IB Biology SL Flashcards: Complete Course Review
Review the current IB Biology Standard Level course with 960 independently written active-recall cards covering all 34 SL topics across molecules, cells, organisms, genetics, evolution, and ecology.
Bu deste hakkında
Study the current IB Biology SL course with 960 independently written English flashcards. The deck covers all 34 Standard Level topics through four broad groups: molecules and cells; metabolism and genetics; organisms and systems; and evolution and ecology.
Cards move from essential terms and structures to functions, mechanisms, comparisons, predictions, and compact interpretation prompts. Useful two-way term cards are separated by at least three unrelated cards, while explanatory answers are kept in the direction that supports meaningful recall. Every card carries the root tag ib-bio-sl and exactly one broad group tag.
The order introduces prerequisite ideas before dependent ones and progresses from simpler recall to more demanding reasoning within each topic. The deck is designed for ongoing spaced review. It does not replace data-heavy practice papers, extended-response practice, laboratory work, or the scientific investigation.
Reviewed in 2026 against the current Biology Standard Level course, first assessed in 2025.
Independent, unofficial study aid based on common biological knowledge. Not affiliated with or endorsed by the International Baccalaureate Organization. No copied IB examination questions, mark schemes, or curriculum text are included.
Check the official IB Biology course page for authoritative requirements.
Bu destedeki kartlar
Kart 1
Soru
What is water polarity?
Cevap
The unequal sharing of electrons in a water molecule, giving oxygen a partial negative charge and the hydrogens partial positive charges.
Kart 2
Soru
What is a hydrogen bond?
Cevap
A weak attraction between a partially positive hydrogen atom and a partially negative atom in another molecule.
Kart 3
Soru
What is cohesion?
Cevap
Attraction between molecules of the same substance.
Kart 4
Soru
What is adhesion?
Cevap
Attraction between molecules of different substances.
Kart 5
Soru
Which term describes unequal charge distribution within a water molecule?
Cevap
water polarity
Kart 6
Soru
Which term describes the intermolecular attraction that links neighboring water molecules?
Cevap
a hydrogen bond
Kart 7
Soru
Which term describes attraction between molecules of the same substance?
Cevap
cohesion
Kart 8
Soru
Which term describes attraction between water and a different material?
Cevap
adhesion
Kart 9
Soru
What is a solvent?
Cevap
A liquid that dissolves solutes to form a solution.
Kart 10
Soru
What is specific heat capacity?
Cevap
The energy required to raise the temperature of a unit mass of a substance by one degree.
Kart 11
Soru
What is latent heat of vaporization?
Cevap
The energy required to vaporize a specified amount of liquid without changing its temperature.
Kart 12
Soru
Why does ice float on liquid water?
Cevap
Hydrogen bonds hold water molecules in an open lattice in ice, making ice less dense than liquid water.
Kart 13
Soru
Which term describes a liquid that dissolves solutes?
Cevap
a solvent
Kart 14
Soru
Which term describes the energy needed to raise a unit mass by one degree?
Cevap
specific heat capacity
Kart 15
Soru
Which term describes the energy needed to vaporize a liquid without a temperature change?
Cevap
latent heat of vaporization
Kart 16
Soru
Which property of water makes sweating an effective cooling mechanism?
Cevap
Water absorbs substantial energy as it evaporates; the highest-energy molecules leave, carrying heat away from the skin.
Kart 17
Soru
Why does water resist rapid temperature change?
Cevap
Many hydrogen bonds must absorb energy before molecular motion increases substantially, giving water a high specific heat capacity.
Kart 18
Soru
How do cohesion and adhesion support water transport in narrow tubes?
Cevap
Cohesion keeps water molecules connected, while adhesion helps the water column cling to the tube wall.
Kart 19
Soru
How does water participate differently in hydrolysis and condensation?
Cevap
Hydrolysis consumes water to split a bond; condensation forms a bond and releases water.
Kart 20
Soru
How does floating ice protect aquatic life in winter?
Cevap
Surface ice insulates the liquid water below, slowing further heat loss and preventing the whole body of water from freezing rapidly.
Kart 21
Soru
Why is water effective for transporting many biological solutes?
Cevap
Its polarity allows ions and other polar molecules to become surrounded and dispersed in solution.
Kart 22
Soru
Why do nonpolar substances tend to cluster in water?
Cevap
Clustering reduces the nonpolar surface exposed to water, allowing more water molecules to maintain hydrogen-bond interactions.
Kart 23
Soru
What is a nucleotide?
Cevap
A nucleic-acid monomer made of a pentose sugar, a phosphate group, and a nitrogenous base.
Kart 24
Soru
What is a nucleoside?
Cevap
A nitrogenous base joined to a pentose sugar, without a phosphate group.
Kart 25
Soru
What is a phosphodiester bond?
Cevap
A covalent bond linking the phosphate of one nucleotide to the sugar of the next nucleotide.
Kart 26
Soru
What is DNA?
Cevap
A usually double-stranded nucleic acid that stores hereditary information in its base sequence.
Kart 27
Soru
Which term describes a sugar-phosphate-base monomer?
Cevap
a nucleotide
Kart 28
Soru
Which term describes a base joined to a sugar but no phosphate?
Cevap
a nucleoside
Kart 29
Soru
Which term describes the covalent linkage in a nucleic-acid sugar-phosphate backbone?
Cevap
a phosphodiester bond
Kart 30
Soru
Which term describes the nucleic acid that usually stores hereditary information?
Cevap
DNA
Kart 31
Soru
What is RNA?
Cevap
A usually single-stranded nucleic acid involved in expressing and regulating genetic information.
Kart 32
Soru
What are antiparallel DNA strands?
Cevap
Two DNA strands that run in opposite 5′ to 3′ directions.
Kart 33
Soru
What is complementary base pairing?
Cevap
Specific pairing in which adenine pairs with thymine in DNA, or uracil in RNA, and cytosine pairs with guanine.
Kart 34
Soru
What is a purine?
Cevap
A nitrogenous base with two fused rings; adenine and guanine are purines.
Kart 35
Soru
Which term describes the usually single-stranded nucleic acid used in gene expression?
Cevap
RNA
Kart 36
Soru
Which term describes DNA strands running in opposite directions?
Cevap
antiparallel DNA strands
Kart 37
Soru
Which term describes specific A–T or A–U and C–G pairing?
Cevap
complementary base pairing
Kart 38
Soru
Which term describes a two-ring nitrogenous base?
Cevap
a purine
Kart 39
Soru
What is a pyrimidine?
Cevap
A nitrogenous base with one ring; cytosine, thymine, and uracil are pyrimidines.
Kart 40
Soru
What is a genome?
Cevap
The complete genetic material of an organism or cell.
Kart 41
Soru
What three structural features commonly distinguish RNA from DNA?
Cevap
RNA usually contains ribose, uses uracil instead of thymine, and is single-stranded rather than double-stranded.
Kart 42
Soru
What determines the base sequence of the second DNA strand?
Cevap
Complementary base-pairing rules determine it: A pairs with T, and C pairs with G.
Kart 43
Soru
Which term describes a one-ring nitrogenous base?
Cevap
a pyrimidine
Kart 44
Soru
Which term describes the complete genetic material of an organism?
Cevap
a genome
Kart 45
Soru
What do the 5′ and 3′ labels of a nucleic-acid strand refer to?
Cevap
They refer to numbered carbon atoms in the pentose sugar and define the strand's chemical direction.
Kart 46
Soru
Where is genetic information encoded in DNA?
Cevap
In the order of nitrogenous bases along the DNA strand.
Kart 47
Soru
Why is ATP classified as a nucleotide?
Cevap
It contains adenine, ribose, and phosphate groups, the three component types of a nucleotide.
Kart 48
Soru
How do mRNA, tRNA, and rRNA contribute to protein synthesis?
Cevap
mRNA carries the coding sequence, tRNA delivers amino acids, and rRNA forms the catalytic and structural core of ribosomes.
Kart 49
Soru
How are a gene and a chromosome related?
Cevap
A gene is a DNA sequence with a biological function; a chromosome is one long DNA molecule containing many genes and other sequences.
Kart 50
Soru
What happens to double-stranded DNA when it is denatured by heat?
Cevap
Hydrogen bonds between complementary bases break and the two strands separate; the covalent backbones usually remain intact.
Kart 51
Soru
Why can each DNA strand serve as a template during replication?
Cevap
Its base sequence determines a complementary sequence through specific base pairing.
Kart 52
Soru
In which direction are new nucleic-acid strands synthesized?
Cevap
Nucleotides are added to the 3′ end, so synthesis proceeds 5′ to 3′.
Kart 53
Soru
What is a monosaccharide?
Cevap
A single sugar unit that can serve as a carbohydrate monomer.
Kart 54
Soru
What is a disaccharide?
Cevap
A carbohydrate formed from two monosaccharides joined by a glycosidic bond.
Kart 55
Soru
What is a polysaccharide?
Cevap
A polymer made from many monosaccharide units.
Kart 56
Soru
What is a glycosidic bond?
Cevap
A covalent bond joining monosaccharides in a carbohydrate.
Kart 57
Soru
Which term describes a single sugar unit?
Cevap
a monosaccharide
Kart 58
Soru
Which term describes two monosaccharides joined together?
Cevap
a disaccharide
Kart 59
Soru
Which term describes a polymer of many sugar units?
Cevap
a polysaccharide
Kart 60
Soru
Which term describes the covalent linkage between monosaccharides?
Cevap
a glycosidic bond
Kart 61
Soru
What is a triglyceride?
Cevap
A lipid formed from glycerol joined to three fatty acids.
Kart 62
Soru
What is a fatty acid?
Cevap
A hydrocarbon chain with a carboxyl group that can form part of many lipids.
Kart 63
Soru
What is a saturated fatty acid?
Cevap
A fatty acid with no carbon-carbon double bonds in its hydrocarbon chain.
Kart 64
Soru
What is a phospholipid?
Cevap
An amphipathic lipid with a phosphate-containing hydrophilic head and hydrophobic fatty-acid tails.
Kart 65
Soru
Which term describes glycerol joined to three fatty acids?
Cevap
a triglyceride
Kart 66
Soru
Which term describes a hydrocarbon chain ending in a carboxyl group?
Cevap
a fatty acid
Kart 67
Soru
Which term describes a fatty acid without carbon-carbon double bonds?
Cevap
a saturated fatty acid
Kart 68
Soru
Which term describes a lipid with a polar head and nonpolar tails?
Cevap
a phospholipid
Kart 69
Soru
How is a glycosidic bond formed between two monosaccharides?
Cevap
A condensation reaction joins them and releases a molecule of water.
Kart 70
Soru
How is a polysaccharide broken into smaller sugars?
Cevap
Hydrolysis adds water across glycosidic bonds, splitting the polymer.
Kart 71
Soru
Which polysaccharides store glucose in plants and animals?
Cevap
Starch stores glucose in plants; glycogen stores glucose in animals and fungi.
Kart 72
Soru
Why is cellulose suitable for plant cell walls?
Cevap
Its straight β-glucose chains hydrogen-bond into strong microfibrils that resist stretching.
Kart 73
Soru
Why do lipids store more energy per gram than carbohydrates?
Cevap
Lipids contain more energy-rich carbon-hydrogen bonds and are more reduced.
Kart 74
Soru
Why do phospholipids form bilayers in water?
Cevap
Hydrophilic heads interact with water while hydrophobic tails cluster away from water.
Kart 75
Soru
Besides energy storage, what are three biological roles of lipids?
Cevap
They form membranes, provide thermal insulation and cushioning, and can act as signaling molecules.
Kart 76
Soru
How do cis double bonds affect fatty-acid packing and melting point?
Cevap
They introduce bends that reduce close packing, usually lowering the melting point.
Kart 77
Soru
What is an amino acid?
Cevap
A protein monomer with an amino group, a carboxyl group, a hydrogen, and a variable R group attached to a central carbon.
Kart 78
Soru
What is a peptide bond?
Cevap
The covalent bond formed between the amino group of one amino acid and the carboxyl group of another.
Kart 79
Soru
What is a polypeptide?
Cevap
A chain of amino acids joined by peptide bonds.
Kart 80
Soru
What is protein primary structure?
Cevap
The amino-acid sequence of a polypeptide.
Kart 81
Soru
Which term describes a protein monomer with amino, carboxyl, and variable R groups?
Cevap
an amino acid
Kart 82
Soru
Which term describes the covalent linkage between amino acids?
Cevap
a peptide bond
Kart 83
Soru
Which term describes a chain of peptide-linked amino acids?
Cevap
a polypeptide
Kart 84
Soru
Which term describes a protein's amino-acid sequence?
Cevap
protein primary structure
Kart 85
Soru
What is protein secondary structure?
Cevap
Local folding such as α-helices and β-sheets stabilized mainly by backbone hydrogen bonds.
Kart 86
Soru
What is protein tertiary structure?
Cevap
The overall three-dimensional shape of one polypeptide produced by interactions among R groups and the backbone.
Kart 87
Soru
What is protein quaternary structure?
Cevap
The arrangement of multiple polypeptide subunits in one functional protein.
Kart 88
Soru
What is protein denaturation?
Cevap
Loss of a protein's normal three-dimensional shape and therefore usually its function.
Kart 89
Soru
Which term describes local α-helix and β-sheet folding?
Cevap
protein secondary structure
Kart 90
Soru
Which term describes the overall three-dimensional shape of one polypeptide?
Cevap
protein tertiary structure
Kart 91
Soru
Which term describes the association of multiple polypeptide subunits?
Cevap
protein quaternary structure
Kart 92
Soru
Which term describes loss of a protein's native shape?
Cevap
protein denaturation
Kart 93
Soru
What mainly gives different amino acids their different chemical properties?
Cevap
Their variable R groups.
Kart 94
Soru
What reaction forms a peptide bond?
Cevap
A condensation reaction releases water as the amino and carboxyl groups join.
Kart 95
Soru
Why can high temperature denature a protein?
Cevap
Increased molecular motion disrupts weak interactions that maintain the protein's shape.
Kart 96
Soru
Why can extreme pH denature a protein?
Cevap
It changes the charges of R groups and disrupts ionic and hydrogen-bond interactions.
Kart 97
Soru
How do fibrous and globular proteins generally differ?
Cevap
Fibrous proteins are elongated and mainly structural; globular proteins are compact and often perform dynamic functions.
Kart 98
Soru
Why is three-dimensional shape crucial to protein function?
Cevap
It creates specific binding, catalytic, structural, or interaction surfaces.
Kart 99
Soru
Name four broad biological roles of proteins.
Cevap
Catalysis, transport, signaling, defense, movement, and structural support are major roles; any four are sufficient.
Kart 100
Soru
How can changing one amino acid alter protein function?
Cevap
The substitution can change R-group interactions, folding, stability, or an active or binding site.
Kart 101
Soru
What is cell theory?
Cevap
The principles that living organisms are made of cells, cells are the basic units of life, and cells arise from pre-existing cells.
Kart 102
Soru
What is a prokaryotic cell?
Cevap
A cell without a nucleus or other membrane-bound organelles.
Kart 103
Soru
What is a eukaryotic cell?
Cevap
A cell with DNA enclosed in a nucleus and with membrane-bound organelles.
Kart 104
Soru
What is the nucleus?
Cevap
The double-membrane organelle that contains most of a eukaryotic cell's DNA.
Kart 105
Soru
Which term describes the principles describing cells as life's basic units?
Cevap
cell theory
Kart 106
Soru
Which term describes a cell lacking a nucleus and membrane-bound organelles?
Cevap
a prokaryotic cell
Kart 107
Soru
Which term describes a cell with a nucleus and membrane-bound organelles?
Cevap
a eukaryotic cell
Kart 108
Soru
Which term describes the organelle containing most eukaryotic DNA?
Cevap
the nucleus
Kart 109
Soru
What is a ribosome?
Cevap
A molecular complex of rRNA and proteins that synthesizes polypeptides.
Kart 110
Soru
What is the cytoplasm?
Cevap
The material inside the plasma membrane but outside the nucleus, including cytosol and organelles.
Kart 111
Soru
What is the plasma membrane?
Cevap
The selectively permeable boundary separating a cell from its environment.
Kart 112
Soru
What is a cell wall?
Cevap
A rigid extracellular layer that supports and protects cells in plants, fungi, and most prokaryotes.
Kart 113
Soru
Which term describes the complex that synthesizes polypeptides?
Cevap
a ribosome
Kart 114
Soru
Which term describes cell contents inside the plasma membrane but outside the nucleus?
Cevap
the cytoplasm
Kart 115
Soru
Which term describes the selectively permeable cell boundary?
Cevap
the plasma membrane
Kart 116
Soru
Which term describes a rigid extracellular support layer?
Cevap
a cell wall
Kart 117
Soru
What is the nucleoid?
Cevap
The non-membrane-bound region containing the main chromosome of a prokaryotic cell.
Kart 118
Soru
What is the cytoskeleton?
Cevap
A dynamic network of protein filaments involved in cell shape, transport, division, and movement.
Kart 119
Soru
What structures are shared by all cells?
Cevap
A plasma membrane, cytoplasm, genetic material, and ribosomes.
Kart 120
Soru
Which structures distinguish a typical plant cell from a typical animal cell?
Cevap
A plant cell has a cellulose wall, chloroplasts in photosynthetic tissues, and a large central vacuole; an animal cell lacks these.
Kart 121
Soru
Which term describes the prokaryotic chromosome-containing region?
Cevap
the nucleoid
Kart 122
Soru
Which term describes the internal network of protein filaments?
Cevap
the cytoskeleton
Kart 123
Soru
How is genetic material commonly organized in a prokaryotic cell?
Cevap
The main DNA is usually one circular chromosome in the nucleoid, often accompanied by smaller plasmids.
Kart 124
Soru
How is microscope magnification calculated?
Cevap
Magnification = image size ÷ actual size, using the same units.
Kart 125
Soru
What does microscope resolution describe?
Cevap
The ability to distinguish two close points as separate.
Kart 126
Soru
Arrange these from smallest to largest: ribosome, bacterium, animal cell.
Cevap
Ribosome, bacterium, animal cell.
Kart 127
Soru
How does the cytoskeleton support intracellular transport?
Cevap
Motor proteins move vesicles and other cargo along cytoskeletal filaments.
Kart 128
Soru
Why does a small cell usually exchange materials more efficiently than a geometrically similar large cell?
Cevap
It has a larger surface-area-to-volume ratio, providing more exchange surface per unit of cell contents.
Kart 129
Soru
Why is a cell more than a collection of isolated molecules?
Cevap
Organized interactions among components produce emergent functions such as metabolism, regulation, and reproduction.
Kart 130
Soru
What major advantage do membrane-bound organelles give eukaryotic cells?
Cevap
They separate incompatible reactions and create specialized local conditions.
Kart 131
Soru
What is a phospholipid bilayer?
Cevap
A double layer of phospholipids with hydrophilic heads facing water and hydrophobic tails facing inward.
Kart 132
Soru
What is the fluid mosaic model?
Cevap
A model describing membranes as mobile phospholipids containing a changing mosaic of proteins and other components.
Kart 133
Soru
What is an integral membrane protein?
Cevap
A protein embedded in the bilayer, often spanning it.
Kart 134
Soru
What is a peripheral membrane protein?
Cevap
A protein attached to a membrane surface rather than embedded in the bilayer.
Kart 135
Soru
Which term describes a double phospholipid layer with inward-facing tails?
Cevap
a phospholipid bilayer
Kart 136
Soru
Which term describes the model of a mobile lipid layer containing varied proteins?
Cevap
the fluid mosaic model
Kart 137
Soru
Which term describes a protein embedded within the lipid bilayer?
Cevap
an integral membrane protein
Kart 138
Soru
Which term describes a protein attached to a membrane surface?
Cevap
a peripheral membrane protein
Kart 139
Soru
What is membrane cholesterol?
Cevap
An amphipathic lipid that buffers membrane fluidity and reduces permeability in animal cells.
Kart 140
Soru
What is a glycoprotein?
Cevap
A protein with an attached carbohydrate chain, often used in recognition, adhesion, or signaling.
Kart 141
Soru
What is diffusion?
Cevap
Net movement of particles from a region of higher concentration to lower concentration due to random motion.
Kart 142
Soru
What is osmosis?
Cevap
Net movement of water across a selectively permeable membrane from higher water potential to lower water potential.
Kart 143
Soru
Which term describes the animal-membrane lipid that buffers fluidity?
Cevap
membrane cholesterol
Kart 144
Soru
Which term describes a carbohydrate-bearing protein?
Cevap
a glycoprotein
Kart 145
Soru
Which term describes net movement down a concentration gradient?
Cevap
diffusion
Kart 146
Soru
Which term describes net water movement across a selectively permeable membrane?
Cevap
osmosis
Kart 147
Soru
What is facilitated diffusion?
Cevap
Passive movement down a gradient through a membrane channel or carrier protein.
Kart 148
Soru
What is active transport?
Cevap
Energy-requiring movement of a substance against its concentration or electrochemical gradient.
Kart 149
Soru
Why is the phospholipid bilayer selectively permeable?
Cevap
Its hydrophobic interior allows small nonpolar molecules through more readily than ions and most large or polar molecules.
Kart 150
Soru
How do simple diffusion and facilitated diffusion differ?
Cevap
Both are passive, but facilitated diffusion uses specific membrane proteins while simple diffusion passes through the bilayer.
Kart 151
Soru
Which term describes passive transport through a channel or carrier?
Cevap
facilitated diffusion
Kart 152
Soru
Which term describes energy-dependent transport against a gradient?
Cevap
active transport
Kart 153
Soru
How do channel and carrier proteins differ?
Cevap
Channels provide hydrophilic pores; carriers bind solutes and change shape to move them.
Kart 154
Soru
How can an ATP-driven pump maintain an ion gradient?
Cevap
It couples ATP hydrolysis to a conformational change that moves ions against their electrochemical gradient.
Kart 155
Soru
How does endocytosis move material into a cell?
Cevap
The plasma membrane folds inward and pinches off a vesicle containing the material.
Kart 156
Soru
How does exocytosis move material out of a cell?
Cevap
An intracellular vesicle fuses with the plasma membrane and releases its contents outside.
Kart 157
Soru
What happens to an animal cell in a strongly hypotonic solution?
Cevap
Water enters by osmosis; without a cell wall, the cell may swell and lyse.
Kart 158
Soru
Does molecular movement stop when diffusion reaches equilibrium?
Cevap
No. Molecules continue moving randomly, but there is no net movement between regions.
Kart 159
Soru
How does decreasing temperature generally affect membrane fluidity?
Cevap
It reduces phospholipid movement and makes the membrane less fluid.
Kart 160
Soru
Why do unsaturated fatty-acid tails increase membrane fluidity?
Cevap
Their cis double-bond bends prevent phospholipids from packing tightly.
Kart 161
Soru
What changes increase the rate of simple diffusion across a membrane?
Cevap
A steeper gradient, larger surface area, higher temperature, shorter distance, and greater membrane permeability increase the rate.
Kart 162
Soru
What is a mitochondrion?
Cevap
A double-membrane organelle where most aerobic ATP production occurs.
Kart 163
Soru
What is a chloroplast?
Cevap
A double-membrane organelle where photosynthesis occurs in plants and algae.
Kart 164
Soru
What is rough endoplasmic reticulum?
Cevap
A membrane network bearing ribosomes that synthesizes and begins processing many secreted and membrane proteins.
Kart 165
Soru
What is smooth endoplasmic reticulum?
Cevap
A membrane network involved in lipid synthesis, detoxification, and calcium storage.
Kart 166
Soru
Which term describes the main organelle of aerobic ATP production?
Cevap
a mitochondrion
Kart 167
Soru
Which term describes the photosynthetic organelle of plants and algae?
Cevap
a chloroplast
Kart 168
Soru
Which term describes the ribosome-studded membrane network?
Cevap
rough endoplasmic reticulum
Kart 169
Soru
Which term describes the membrane network that lacks ribosomes and synthesizes lipids?
Cevap
smooth endoplasmic reticulum
Kart 170
Soru
What is the Golgi apparatus?
Cevap
Stacked membranes that modify, sort, and package proteins and lipids into vesicles.
Kart 171
Soru
What is a lysosome?
Cevap
An acidic enzyme-containing organelle that digests macromolecules and worn cellular components.
Kart 172
Soru
What is a vesicle?
Cevap
A small membrane-bound compartment used for transport, storage, or chemical reactions.
Kart 173
Soru
What is the central vacuole?
Cevap
A large plant-cell compartment that stores solutes and helps maintain turgor pressure.
Kart 174
Soru
Which term describes the organelle that modifies and sorts cellular cargo?
Cevap
the Golgi apparatus
Kart 175
Soru
Which term describes the acidic digestive organelle?
Cevap
a lysosome
Kart 176
Soru
Which term describes a small membrane-bound transport compartment?
Cevap
a vesicle
Kart 177
Soru
Which term describes the large plant compartment that supports turgor?
Cevap
the central vacuole
Kart 178
Soru
Why can compartmentalization increase metabolic efficiency?
Cevap
It concentrates enzymes and substrates, maintains suitable local conditions, and separates incompatible reactions.
Kart 179
Soru
How do mitochondrial cristae support ATP production?
Cevap
They increase inner-membrane area for electron transport chains and ATP synthase.
Kart 180
Soru
Why are chloroplast thylakoids arranged as extensive membranes?
Cevap
They provide a large surface for light-absorbing complexes, electron transport chains, and ATP synthase.
Kart 181
Soru
What is the main function of the nucleolus?
Cevap
It produces rRNA and assembles ribosomal subunits.
Kart 182
Soru
Trace a secreted protein from synthesis to release.
Cevap
Ribosome on rough ER → ER lumen → transport vesicle → Golgi apparatus → secretory vesicle → plasma membrane → exocytosis.
Kart 183
Soru
Why does a lysosome maintain an acidic interior?
Cevap
Its hydrolytic enzymes work best at low pH, and acidity helps confine their activity from the cytosol.
Kart 184
Soru
How do the nucleus, ribosomes, ER, and Golgi cooperate in protein production?
Cevap
DNA instructions are transcribed in the nucleus; ribosomes translate them; ER folds or modifies many products; Golgi further modifies and sorts them.
Kart 185
Soru
How are transport vesicles directed to the correct target membrane?
Cevap
Specific recognition proteins on vesicles and target membranes interact, allowing selective docking and fusion.
Kart 186
Soru
What is cell differentiation?
Cevap
The process by which a cell develops specialized structure and function.
Kart 187
Soru
What is a stem cell?
Cevap
An unspecialized cell able to self-renew and produce differentiated cells.
Kart 188
Soru
What is gene expression?
Cevap
Use of genetic information to produce a functional RNA or protein product.
Kart 189
Soru
What is a tissue?
Cevap
A coordinated group of similar or related cells performing a shared function.
Kart 190
Soru
Which term describes development of specialized cell structure and function?
Cevap
cell differentiation
Kart 191
Soru
Which term describes an unspecialized self-renewing cell?
Cevap
a stem cell
Kart 192
Soru
Which term describes production of a functional product from genetic information?
Cevap
gene expression
Kart 193
Soru
Which term describes a group of coordinated cells with a shared function?
Cevap
a tissue
Kart 194
Soru
What is an organ?
Cevap
A structure made of multiple tissues working together for particular functions.
Kart 195
Soru
What is the organ-system level of biological organization?
Cevap
A group of organs that coordinate to perform major functions for an organism.
Kart 196
Soru
What is surface-area-to-volume ratio?
Cevap
The amount of surface area available relative to the volume it must serve.
Kart 197
Soru
How can two specialized cells have the same genome but different structures?
Cevap
They express different sets and amounts of genes, producing different proteins and cellular features.
Kart 198
Soru
Which term describes a structure composed of multiple tissue types?
Cevap
an organ
Kart 199
Soru
Which term describes the level of biological organization formed by coordinated organs?
Cevap
an organ system
Kart 200
Soru
Which term describes surface area available per unit volume?
Cevap
surface-area-to-volume ratio
Kart 201
Soru
How is a mammalian red blood cell specialized for oxygen transport?
Cevap
Its biconcave shape increases exchange area, it is flexible, and loss of its nucleus leaves more space for hemoglobin.
Kart 202
Soru
How is a sperm cell specialized for fertilization?
Cevap
It has a flagellum for movement, many mitochondria for ATP, a haploid nucleus, and an acrosome containing enzymes.
Kart 203
Soru
How is a neuron specialized for rapid communication?
Cevap
Long processes carry signals over distance, branching dendrites receive inputs, and synaptic terminals transmit signals to other cells.
Kart 204
Soru
How is a root hair cell specialized for mineral and water uptake?
Cevap
Its long projection increases surface area, its thin wall shortens the pathway, and membrane transport proteins take up ions.
Kart 205
Soru
How is a palisade mesophyll cell specialized for photosynthesis?
Cevap
It contains many chloroplasts and is positioned near the upper leaf surface where light is strongest.
Kart 206
Soru
How do ciliated epithelial cells help protect airways?
Cevap
Their cilia move mucus containing trapped particles and microbes toward the throat.
Kart 207
Soru
Why can extreme specialization reduce a cell's independence?
Cevap
Resources and structures are committed to a narrow role, so the cell depends on other cells for functions it no longer performs well.
Kart 208
Soru
What is water potential?
Cevap
The potential energy of water per unit volume relative to pure water, used to predict the direction of water movement.
Kart 209
Soru
What is solute potential?
Cevap
The negative contribution of dissolved solutes to water potential.
Kart 210
Soru
What is pressure potential?
Cevap
The contribution of physical pressure to water potential.
Kart 211
Soru
What is turgor pressure?
Cevap
Outward pressure of a plant-cell interior against its cell wall after water uptake.
Kart 212
Soru
Which term describes the tendency of water to move relative to pure water?
Cevap
water potential
Kart 213
Soru
Which term describes the water-potential component lowered by dissolved solutes?
Cevap
solute potential
Kart 214
Soru
Which term describes the water-potential component caused by physical pressure?
Cevap
pressure potential
Kart 215
Soru
Which term describes pressure of plant-cell contents against the wall?
Cevap
turgor pressure
Kart 216
Soru
What is plasmolysis?
Cevap
Separation of the plasma membrane from the cell wall after a plant cell loses water.
Kart 217
Soru
What is a flaccid plant cell?
Cevap
A plant cell with insufficient turgor pressure to be firm.
Kart 218
Soru
What is an isotonic condition?
Cevap
A condition in which two solutions have equal effective water potential and no net water movement occurs.
Kart 219
Soru
In which direction does water move across a permeable membrane?
Cevap
From higher water potential to lower water potential.
Kart 220
Soru
Which term describes membrane separation from the plant cell wall after water loss?
Cevap
plasmolysis
Kart 221
Soru
Which term describes a plant cell lacking firm turgor?
Cevap
a flaccid plant cell
Kart 222
Soru
Which term describes equal effective water potential across a membrane?
Cevap
an isotonic condition
Kart 223
Soru
What is the water potential of pure water at standard pressure?
Cevap
Zero; adding solute makes water potential more negative.
Kart 224
Soru
How are water potential, solute potential, and pressure potential related?
Cevap
Water potential equals solute potential plus pressure potential: Ψ = Ψs + Ψp.
Kart 225
Soru
Why does a plant cell usually become turgid rather than burst in a hypotonic solution?
Cevap
Water entry raises pressure potential, while the rigid cell wall resists further expansion.
Kart 226
Soru
What happens to a plant cell placed in a solution with much lower water potential?
Cevap
Water leaves the cell, turgor falls, and severe loss can cause plasmolysis.
Kart 227
Soru
Can two solutions have different solute concentrations but equal water potential?
Cevap
Yes. A difference in pressure potential can offset a difference in solute potential.
Kart 228
Soru
What is an enzyme?
Cevap
A biological catalyst that increases reaction rate without being consumed.
Kart 229
Soru
What is an active site?
Cevap
The region of an enzyme where substrate binds and catalysis occurs.
Kart 230
Soru
What is a substrate?
Cevap
A reactant molecule on which an enzyme acts.
Kart 231
Soru
What is activation energy?
Cevap
The minimum energy input needed for a reaction to begin.
Kart 232
Soru
Which term describes a biological catalyst?
Cevap
an enzyme
Kart 233
Soru
Which term describes the substrate-binding catalytic region of an enzyme?
Cevap
an active site
Kart 234
Soru
Which term describes a reactant bound and changed by an enzyme?
Cevap
a substrate
Kart 235
Soru
Which term describes the energy barrier that must be overcome for a reaction?
Cevap
activation energy
Kart 236
Soru
What is the induced-fit model?
Cevap
The model in which substrate binding changes active-site shape to improve catalytic interactions.
Kart 237
Soru
What is enzyme denaturation?
Cevap
Loss of the active three-dimensional shape of an enzyme, usually causing loss of activity.
Kart 238
Soru
What is competitive inhibition?
Cevap
Inhibition caused by a molecule competing with substrate for the active site.
Kart 239
Soru
What is noncompetitive inhibition?
Cevap
Inhibition caused by binding away from the active site and reducing catalytic function.
Kart 240
Soru
Which term describes the model where substrate binding reshapes the active site?
Cevap
the induced-fit model
Kart 241
Soru
Which term describes loss of an enzyme's functional shape?
Cevap
enzyme denaturation
Kart 242
Soru
Which term describes inhibition by active-site competition?
Cevap
competitive inhibition
Kart 243
Soru
Which term describes inhibition by binding outside the active site?
Cevap
noncompetitive inhibition
Kart 244
Soru
What is an enzyme optimum?
Cevap
The condition, such as temperature or pH, at which an enzyme's activity is highest.
Kart 245
Soru
What is feedback inhibition?
Cevap
Control in which a pathway product inhibits an enzyme acting earlier in the pathway.
Kart 246
Soru
How does an enzyme increase reaction rate?
Cevap
It stabilizes the transition state and provides a pathway with lower activation energy.
Kart 247
Soru
Why does enzyme activity often rise and then fall as temperature increases?
Cevap
Molecular collisions initially increase, but excessive heat disrupts enzyme shape and denatures the active site.
Kart 248
Soru
Which term describes the condition producing maximum enzyme activity?
Cevap
an enzyme optimum
Kart 249
Soru
Which term describes pathway control by inhibition from an end product?
Cevap
feedback inhibition
Kart 250
Soru
Why does each enzyme have a characteristic pH range?
Cevap
pH changes the ionization of amino-acid side chains, affecting active-site shape and chemical interactions.
Kart 251
Soru
Why does increasing substrate concentration eventually stop increasing enzyme rate?
Cevap
At saturation, nearly all active sites are occupied and enzyme concentration limits the maximum rate.
Kart 252
Soru
How does increasing enzyme concentration affect rate when substrate is abundant?
Cevap
More active sites are available, so the initial rate increases roughly in proportion to enzyme concentration.
Kart 253
Soru
What gives an enzyme substrate specificity?
Cevap
The active site's shape, charge, polarity, and chemical groups complement particular substrates and transition states.
Kart 254
Soru
What is one practical advantage of immobilizing an enzyme?
Cevap
The enzyme can be separated from products and reused while conditions around it are controlled.
Kart 255
Soru
Does an enzyme change a reaction's equilibrium position?
Cevap
No. It speeds forward and reverse reactions but does not change the equilibrium constant or final equilibrium position.
Kart 256
Soru
How can high substrate concentration reduce competitive inhibition?
Cevap
More substrate molecules increase the chance that substrate rather than inhibitor occupies the active site.
Kart 257
Soru
Why are metabolic reactions commonly organized into pathways?
Cevap
A sequence of enzyme-controlled steps allows energy changes and intermediates to be controlled and coupled.
Kart 258
Soru
What is ATP?
Cevap
A nucleotide that transfers usable energy through coupling of its hydrolysis to cellular processes.
Kart 259
Soru
What is cellular respiration?
Cevap
Controlled release of energy from organic molecules to produce ATP.
Kart 260
Soru
What is glycolysis?
Cevap
A cytosolic pathway that splits glucose into two pyruvate molecules and yields a small amount of ATP and reduced electron carriers.
Kart 261
Soru
What is pyruvate?
Cevap
The three-carbon product of glycolysis that can enter aerobic or anaerobic pathways.
Kart 262
Soru
Which term describes the cell's immediate phosphoryl-group energy carrier?
Cevap
ATP
Kart 263
Soru
Which term describes controlled ATP-producing breakdown of organic molecules?
Cevap
cellular respiration
Kart 264
Soru
Which term describes the cytosolic splitting of glucose into pyruvate?
Cevap
glycolysis
Kart 265
Soru
Which term describes the three-carbon product of glycolysis?
Cevap
pyruvate
Kart 266
Soru
What is aerobic respiration?
Cevap
Respiration that uses oxygen as the final electron acceptor and produces much more ATP than fermentation.
Kart 267
Soru
What is anaerobic metabolism?
Cevap
ATP-producing metabolism that proceeds without oxygen.
Kart 268
Soru
What is fermentation?
Cevap
An anaerobic pathway that regenerates oxidized electron carriers so glycolysis can continue.
Kart 269
Soru
What is oxidation?
Cevap
Loss of electrons, often accompanied in biology by loss of hydrogen or gain of oxygen.
Kart 270
Soru
Which term describes respiration using oxygen as final electron acceptor?
Cevap
aerobic respiration
Kart 271
Soru
Which term describes ATP-producing metabolism without oxygen?
Cevap
anaerobic metabolism
Kart 272
Soru
Which term describes anaerobic regeneration of electron carriers after glycolysis?
Cevap
fermentation
Kart 273
Soru
Which term describes loss of electrons?
Cevap
oxidation
Kart 274
Soru
What is reduction?
Cevap
Gain of electrons, often accompanied in biology by gain of hydrogen or loss of oxygen.
Kart 275
Soru
What is a reduced electron carrier?
Cevap
A molecule such as NADH that carries high-energy electrons and hydrogen from one reaction to another.
Kart 276
Soru
What is chemiosmosis?
Cevap
ATP production driven by ions moving down an electrochemical gradient through ATP synthase.
Kart 277
Soru
What is the overall word equation for aerobic respiration of glucose?
Cevap
Glucose + oxygen → carbon dioxide + water + energy transferred to ATP and heat.
Kart 278
Soru
Which term describes gain of electrons?
Cevap
reduction
Kart 279
Soru
Which term describes a molecule carrying high-energy electrons between reactions?
Cevap
a reduced electron carrier
Kart 280
Soru
Which term describes ATP production powered by an ion gradient?
Cevap
chemiosmosis
Kart 281
Soru
Where does glycolysis occur?
Cevap
In the cytosol.
Kart 282
Soru
What major stages of aerobic respiration occur in mitochondria?
Cevap
Pyruvate oxidation and the citric acid cycle occur in the matrix; electron transport and chemiosmosis occur at the inner membrane.
Kart 283
Soru
What is oxygen's direct role in aerobic respiration?
Cevap
It accepts electrons and hydrogen ions at the end of the electron transport chain, forming water.
Kart 284
Soru
Why does aerobic respiration yield much more ATP per glucose than fermentation?
Cevap
It transfers electrons through an electron transport chain and uses oxidative phosphorylation, extracting far more of glucose's energy.
Kart 285
Soru
What is the purpose of lactate formation in oxygen-limited animal cells?
Cevap
It regenerates NAD⁺ so glycolysis can continue producing a small amount of ATP.
Kart 286
Soru
What products are formed during alcoholic fermentation in yeast?
Cevap
Ethanol and carbon dioxide, while NAD⁺ is regenerated.
Kart 287
Soru
Why is some energy released by respiration transferred as heat rather than captured in ATP?
Cevap
Energy conversions are not fully efficient, so part of the chemical energy becomes disordered molecular motion.
Kart 288
Soru
What is substrate-level phosphorylation?
Cevap
Direct transfer of a phosphate group from a metabolic intermediate to ADP to form ATP.
Kart 289
Soru
How does electron transport lead to ATP synthesis in mitochondria?
Cevap
Electron energy pumps protons across the inner membrane; proton flow back through ATP synthase drives ATP formation.
Kart 290
Soru
Why can intense exercise increase lactate production?
Cevap
ATP demand can exceed oxygen delivery and aerobic capacity, so cells regenerate NAD⁺ through lactate formation to sustain glycolysis.
Kart 291
Soru
What is photosynthesis?
Cevap
Conversion of light energy into chemical energy used to synthesize organic molecules from carbon dioxide.
Kart 292
Soru
What is chlorophyll?
Cevap
A green pigment that absorbs light energy for photosynthesis.
Kart 293
Soru
What is an absorption spectrum?
Cevap
A graph showing how strongly a pigment absorbs different wavelengths of light.
Kart 294
Soru
What is an action spectrum?
Cevap
A graph showing the rate or effectiveness of photosynthesis at different wavelengths.
Kart 295
Soru
Which term describes light-driven synthesis of organic molecules from carbon dioxide?
Cevap
photosynthesis
Kart 296
Soru
Which term describes the principal green photosynthetic pigment?
Cevap
chlorophyll
Kart 297
Soru
Which term describes a graph of pigment absorption versus wavelength?
Cevap
an absorption spectrum
Kart 298
Soru
Which term describes a graph of photosynthetic effectiveness versus wavelength?
Cevap
an action spectrum
Kart 299
Soru
What is photolysis of water?
Cevap
Light-driven splitting of water that supplies electrons and hydrogen ions and releases oxygen.
Kart 300
Soru
What are light-dependent reactions?
Cevap
Photosynthetic reactions that use light to generate ATP and reduced electron carriers while releasing oxygen.
Kart 301
Soru
What is the Calvin cycle?
Cevap
A set of chloroplast reactions that uses ATP and reduced electron carriers to convert carbon dioxide into carbohydrate precursors.
Kart 302
Soru
What is carbon fixation?
Cevap
Incorporation of inorganic carbon dioxide into an organic molecule.
Kart 303
Soru
Which term describes light-driven splitting of water?
Cevap
photolysis of water
Kart 304
Soru
Which term describes photosynthetic reactions that directly capture light energy?
Cevap
light-dependent reactions
Kart 305
Soru
Which term describes the carbon-reduction cycle of photosynthesis?
Cevap
the Calvin cycle
Kart 306
Soru
Which term describes incorporation of carbon dioxide into organic matter?
Cevap
carbon fixation
Kart 307
Soru
What is the role of a stoma in photosynthesis?
Cevap
A pore in the leaf epidermis that regulates carbon-dioxide entry as well as water loss.
Kart 308
Soru
What is a limiting factor of photosynthesis?
Cevap
The environmental factor whose availability currently restricts the photosynthetic rate.
Kart 309
Soru
What is the light compensation point?
Cevap
The light intensity at which photosynthetic carbon uptake equals respiratory carbon release.
Kart 310
Soru
What is the overall word equation for oxygenic photosynthesis?
Cevap
Carbon dioxide + water → carbohydrate + oxygen, using light energy.
Kart 311
Soru
Which term describes the regulated leaf pore controlling carbon-dioxide entry for photosynthesis?
Cevap
a stoma
Kart 312
Soru
Which term describes the factor currently restricting photosynthetic rate?
Cevap
a limiting factor
Kart 313
Soru
Which term describes the light level where photosynthesis and respiration balance?
Cevap
the light compensation point
Kart 314
Soru
Where do the main stages of photosynthesis occur in a chloroplast?
Cevap
Light-dependent reactions occur in thylakoid membranes; carbon-fixation reactions occur in the stroma.
Kart 315
Soru
What energy conversion occurs during photosynthesis?
Cevap
Light energy is converted into chemical energy stored first in ATP and reduced carriers and ultimately in organic molecules.
Kart 316
Soru
From which reactant does the oxygen released by photosynthesis originate?
Cevap
Water.
Kart 317
Soru
What role does RuBisCO play in photosynthesis?
Cevap
It catalyzes fixation of carbon dioxide by adding it to an organic acceptor molecule.
Kart 318
Soru
What tradeoff is controlled when stomata open?
Cevap
Opening permits carbon dioxide entry but increases water loss by transpiration.
Kart 319
Soru
Name three leaf features that support photosynthesis.
Cevap
A broad surface captures light, a thin structure shortens diffusion paths, and veins supply water and remove sugars; chloroplast-rich cells and stomata also help.
Kart 320
Soru
What can a plant do with carbohydrate made by photosynthesis?
Cevap
Use it in respiration, convert it to storage or structural carbohydrates, or use its carbon to make lipids, amino acids, and other molecules.
Kart 321
Soru
How are products of the light-dependent reactions used in carbon fixation?
Cevap
ATP supplies energy and NADPH supplies reducing power for conversion of fixed carbon into carbohydrate precursors.
Kart 322
Soru
Why does increasing light intensity eventually stop increasing photosynthetic rate?
Cevap
Another factor, such as carbon dioxide supply, temperature, or biochemical capacity, becomes limiting.
Kart 323
Soru
How can increasing carbon dioxide concentration affect photosynthetic rate?
Cevap
It can increase the rate until another factor becomes limiting.
Kart 324
Soru
Why does photosynthetic rate usually have a temperature optimum?
Cevap
Enzyme-controlled reactions accelerate with temperature up to an optimum, then decline as enzymes and membranes lose effective function.
Kart 325
Soru
Why does an action spectrum broadly resemble the combined absorption spectra of photosynthetic pigments?
Cevap
Wavelengths absorbed by the pigments supply more energy for photosynthesis than poorly absorbed wavelengths.
Kart 326
Soru
What is semiconservative replication?
Cevap
DNA replication in which each daughter molecule contains one parental strand and one newly synthesized strand.
Kart 327
Soru
What is DNA helicase?
Cevap
An enzyme that unwinds the double helix and separates the strands by disrupting base pairing.
Kart 328
Soru
What is DNA polymerase?
Cevap
An enzyme that adds nucleotides to a growing DNA strand using a template.
Kart 329
Soru
What is a primer?
Cevap
A short nucleic-acid segment providing a free 3′ end from which DNA polymerase can extend.
Kart 330
Soru
Which term describes replication producing one old and one new strand per DNA molecule?
Cevap
semiconservative replication
Kart 331
Soru
Which term describes the enzyme that separates DNA strands?
Cevap
DNA helicase
Kart 332
Soru
Which term describes the enzyme that builds DNA from a template?
Cevap
DNA polymerase
Kart 333
Soru
Which term describes the short segment providing a starting 3′ end?
Cevap
a primer
Kart 334
Soru
What is the leading strand?
Cevap
The new DNA strand synthesized continuously toward the replication fork.
Kart 335
Soru
What is the lagging strand?
Cevap
The new DNA strand synthesized discontinuously away from the replication fork.
Kart 336
Soru
What is an Okazaki fragment?
Cevap
A short DNA segment synthesized on the lagging strand.
Kart 337
Soru
What is DNA ligase?
Cevap
An enzyme that seals breaks in the sugar-phosphate backbone, joining DNA fragments.
Kart 338
Soru
Which term describes the continuously synthesized daughter strand?
Cevap
the leading strand
Kart 339
Soru
Which term describes the discontinuously synthesized daughter strand?
Cevap
the lagging strand
Kart 340
Soru
Which term describes a short newly made segment of lagging-strand DNA?
Cevap
an Okazaki fragment
Kart 341
Soru
Which term describes the enzyme that joins DNA fragments by sealing the backbone?
Cevap
DNA ligase
Kart 342
Soru
How does complementary base pairing ensure accurate DNA copying?
Cevap
Each template base specifies the nucleotide added opposite it: A pairs with T, and C pairs with G.
Kart 343
Soru
Why does DNA polymerase synthesize DNA only 5′ to 3′?
Cevap
It can add a nucleotide only to the free 3′ hydroxyl group of the growing strand.
Kart 344
Soru
When in the cell cycle is nuclear DNA replicated?
Cevap
During S phase of interphase, before cell division.
Kart 345
Soru
How can a replication error become a permanent mutation?
Cevap
If it escapes proofreading and repair, the altered sequence can be copied in later cell generations.
Kart 346
Soru
Why are leading and lagging strands synthesized differently?
Cevap
The templates are antiparallel while DNA polymerase works only 5′ to 3′, forcing one strand to be made discontinuously.
Kart 347
Soru
How do proofreading and repair reduce replication errors?
Cevap
Incorrectly paired nucleotides are recognized, removed, and replaced before or after replication continues.
Kart 348
Soru
What three repeating steps amplify DNA in PCR?
Cevap
Strand separation by heating, primer annealing during cooling, and DNA extension by a heat-stable polymerase.
Kart 349
Soru
What determines which DNA region PCR amplifies?
Cevap
The sequences and positions of the two primers flanking the target region.
Kart 350
Soru
What is transcription?
Cevap
Synthesis of RNA from a DNA template.
Kart 351
Soru
What is RNA polymerase?
Cevap
The enzyme that synthesizes RNA complementary to a DNA template strand.
Kart 352
Soru
What is messenger RNA?
Cevap
RNA carrying a coding sequence from DNA to ribosomes.
Kart 353
Soru
What is a codon?
Cevap
A three-base sequence in mRNA that specifies an amino acid or a translation signal.
Kart 354
Soru
Which term describes RNA synthesis from DNA?
Cevap
transcription
Kart 355
Soru
Which term describes the enzyme that builds RNA from a DNA template?
Cevap
RNA polymerase
Kart 356
Soru
Which term describes RNA that carries coding information to ribosomes?
Cevap
messenger RNA
Kart 357
Soru
Which term describes a three-base mRNA unit?
Cevap
a codon
Kart 358
Soru
What is translation?
Cevap
Synthesis of a polypeptide using the codon sequence of mRNA.
Kart 359
Soru
What does a ribosome do during translation?
Cevap
It reads mRNA and catalyzes polypeptide synthesis using its rRNA-protein machinery.
Kart 360
Soru
What is transfer RNA?
Cevap
RNA that carries a specific amino acid and pairs its anticodon with an mRNA codon.
Kart 361
Soru
What is an anticodon?
Cevap
A three-base tRNA sequence complementary to an mRNA codon.
Kart 362
Soru
Which term describes polypeptide synthesis from an mRNA sequence?
Cevap
translation
Kart 363
Soru
Which term describes the translation complex that reads mRNA and builds a polypeptide?
Cevap
a ribosome
Kart 364
Soru
Which term describes the adaptor RNA carrying an amino acid?
Cevap
transfer RNA
Kart 365
Soru
Which term describes the tRNA triplet that pairs with a codon?
Cevap
an anticodon
Kart 366
Soru
What is the genetic code?
Cevap
The set of rules relating mRNA codons to amino acids and translation signals.
Kart 367
Soru
What are start and stop codons?
Cevap
mRNA signals that establish the reading frame or terminate translation.
Kart 368
Soru
Where do transcription and translation occur in a eukaryotic cell?
Cevap
Transcription occurs in the nucleus; translation occurs on ribosomes in the cytoplasm or on rough ER.
Kart 369
Soru
How is an mRNA sequence related to its DNA template strand?
Cevap
It is complementary and antiparallel, with uracil in RNA opposite adenine in DNA.
Kart 370
Soru
Which term describes the codon-to-amino-acid rule set?
Cevap
the genetic code
Kart 371
Soru
Which term describes codons that begin or end translation?
Cevap
start and stop codons
Kart 372
Soru
What reaction does the ribosome catalyze as a polypeptide grows?
Cevap
Formation of peptide bonds between adjacent amino acids.
Kart 373
Soru
What does it mean that the genetic code is degenerate?
Cevap
Most amino acids are specified by more than one codon.
Kart 374
Soru
How can one mRNA produce many polypeptides quickly?
Cevap
Multiple ribosomes can translate the same mRNA simultaneously as a polyribosome.
Kart 375
Soru
Why is translation not the final step in producing many functional proteins?
Cevap
The polypeptide must fold and may undergo cleavage, chemical modification, or assembly with other subunits.
Kart 376
Soru
How does mRNA compare with the DNA coding strand?
Cevap
It has the same base sequence except that RNA contains uracil where DNA contains thymine.
Kart 377
Soru
What happens during eukaryotic RNA splicing?
Cevap
Introns are removed and exons are joined to form mature mRNA.
Kart 378
Soru
Why must codons be read in the correct reading frame?
Cevap
Changing the starting position changes every downstream triplet and therefore the amino-acid sequence.
Kart 379
Soru
How is the correct amino acid matched to each mRNA codon?
Cevap
Each tRNA is charged with a particular amino acid, and its anticodon pairs with the complementary codon.
Kart 380
Soru
How can a base substitution affect a protein?
Cevap
It may be silent, change one amino acid, create a stop codon, or sometimes alter RNA processing.
Kart 381
Soru
What is a mutation?
Cevap
A change in a DNA sequence or chromosome structure that can be passed to daughter cells.
Kart 382
Soru
What is a base substitution?
Cevap
Replacement of one nucleotide pair by another.
Kart 383
Soru
What is an insertion mutation?
Cevap
Addition of one or more nucleotides to a DNA sequence.
Kart 384
Soru
What is a deletion mutation?
Cevap
Loss of one or more nucleotides from a DNA sequence.
Kart 385
Soru
Which term describes a lasting DNA-sequence or chromosome change?
Cevap
a mutation
Kart 386
Soru
Which term describes replacement of one DNA base pair?
Cevap
a base substitution
Kart 387
Soru
Which term describes addition of nucleotides to DNA?
Cevap
an insertion mutation
Kart 388
Soru
Which term describes loss of nucleotides from DNA?
Cevap
a deletion mutation
Kart 389
Soru
What is a frameshift mutation?
Cevap
A coding-sequence insertion or deletion not divisible by three that changes downstream codon grouping.
Kart 390
Soru
What is a silent mutation?
Cevap
A sequence change that does not alter the encoded amino acid.
Kart 391
Soru
What is a missense mutation?
Cevap
A mutation that changes a codon so a different amino acid is incorporated.
Kart 392
Soru
What is a nonsense mutation?
Cevap
A mutation that changes an amino-acid codon into a stop codon.
Kart 393
Soru
Which term describes a mutation that shifts downstream codon grouping?
Cevap
a frameshift mutation
Kart 394
Soru
Which term describes a coding change that leaves the amino acid unchanged?
Cevap
a silent mutation
Kart 395
Soru
Which term describes a mutation causing one amino-acid substitution?
Cevap
a missense mutation
Kart 396
Soru
Which term describes a mutation creating a premature stop codon?
Cevap
a nonsense mutation
Kart 397
Soru
How do germline and somatic mutations differ in inheritance?
Cevap
Germline mutations can enter gametes and be inherited; somatic mutations affect a cell lineage within the individual.
Kart 398
Soru
What can cause mutations?
Cevap
Replication errors, spontaneous chemical changes, radiation, and mutagenic chemicals can alter DNA.
Kart 399
Soru
How does DNA repair protect genome stability?
Cevap
Repair systems detect damaged or mismatched DNA and restore the correct structure or sequence when possible.
Kart 400
Soru
Why are mutations essential to evolution despite often being neutral or harmful?
Cevap
They create new alleles, providing the heritable variation on which selection and drift act.
Kart 401
Soru
What is the basic role of guide RNA in CRISPR gene editing?
Cevap
It directs a nuclease to a complementary DNA sequence.
Kart 402
Soru
Why can the same type of DNA mutation have effects ranging from none to severe?
Cevap
Effects depend on location, genetic-code redundancy, protein role, cell type, and environmental context.
Kart 403
Soru
How can accumulated mutations contribute to cancer?
Cevap
Mutations can activate growth-promoting genes or disable genes that restrain division, repair DNA, or trigger cell death.
Kart 404
Soru
Why can repairing a CRISPR-induced DNA break produce different editing outcomes?
Cevap
Different cellular repair pathways may disrupt the target sequence or use a supplied template for a specific change.
Kart 405
Soru
What is an off-target effect in gene editing?
Cevap
An unintended DNA change at a site sufficiently similar to the intended target.
Kart 406
Soru
Why does heritable human genome editing raise additional ethical concerns?
Cevap
Changes could pass to future generations who cannot consent, with uncertain long-term biological and social effects.
Kart 407
Soru
What is the cell cycle?
Cevap
The ordered sequence of cell growth, DNA replication, nuclear division, and cell division.
Kart 408
Soru
What is interphase?
Cevap
The period of growth, normal activity, and DNA replication between nuclear divisions.
Kart 409
Soru
What is mitosis?
Cevap
Nuclear division that usually produces genetically equivalent daughter nuclei.
Kart 410
Soru
What is cytokinesis?
Cevap
Division of the cytoplasm to form separate daughter cells.
Kart 411
Soru
Which term describes the ordered sequence from one cell division to the next?
Cevap
the cell cycle
Kart 412
Soru
Which term describes the growth and DNA-replication period between divisions?
Cevap
interphase
Kart 413
Soru
Which term describes division producing genetically equivalent nuclei?
Cevap
mitosis
Kart 414
Soru
Which term describes physical division of the cytoplasm?
Cevap
cytokinesis
Kart 415
Soru
What is a chromosome?
Cevap
One DNA molecule packaged with associated proteins.
Kart 416
Soru
What are sister chromatids?
Cevap
The two replicated copies of a chromosome joined before separation.
Kart 417
Soru
What is a centromere?
Cevap
The chromosome region that holds sister chromatids together and organizes kinetochore attachment.
Kart 418
Soru
What is the mitotic spindle?
Cevap
A microtubule system that attaches to and separates chromosomes during cell division.
Kart 419
Soru
Which term describes a protein-packaged DNA molecule?
Cevap
a chromosome
Kart 420
Soru
Which term describes joined replicated copies of one chromosome?
Cevap
sister chromatids
Kart 421
Soru
Which term describes the chromosome region joining sister chromatids?
Cevap
a centromere
Kart 422
Soru
Which term describes the chromosome-separating microtubule system?
Cevap
the mitotic spindle
Kart 423
Soru
What is the basic sequence of mitosis?
Cevap
Chromosomes condense, align at the cell equator, sister chromatids separate to opposite poles, and new nuclei form.
Kart 424
Soru
Why must DNA replicate before mitosis?
Cevap
Each chromosome must have two copies so each daughter nucleus can receive a complete genome.
Kart 425
Soru
Why are daughter cells from mitosis usually genetically similar?
Cevap
Replicated sister chromatids are separated so each daughter receives one copy of every chromosome.
Kart 426
Soru
What are major roles of mitosis in multicellular organisms?
Cevap
Growth, tissue repair, cell replacement, and some forms of asexual reproduction.
Kart 427
Soru
How do homologous chromosomes differ from sister chromatids?
Cevap
Homologs carry the same gene loci but may have different alleles; sister chromatids are replicated copies of one chromosome.
Kart 428
Soru
What key outcome distinguishes mitosis from meiosis?
Cevap
Mitosis usually preserves chromosome number and similarity; meiosis halves chromosome number and generates genetically varied haploid cells.
Kart 429
Soru
How does cytokinesis commonly occur in animal cells?
Cevap
A contractile ring tightens the plasma membrane into a cleavage furrow.
Kart 430
Soru
How does cytokinesis commonly occur in plant cells?
Cevap
Vesicles fuse at the center to form a cell plate that develops into new membranes and a cell wall.
Kart 431
Soru
What is the purpose of cell-cycle checkpoints?
Cevap
They delay progression when conditions are unsuitable or DNA and chromosome attachment are defective.
Kart 432
Soru
How is loss of cell-cycle control related to cancer?
Cevap
Cells can divide despite damage or growth restraints, producing an expanding abnormal clone.
Kart 433
Soru
What is a gene?
Cevap
A DNA sequence that contributes to a functional product and influences a characteristic or cellular process.
Kart 434
Soru
What is an allele?
Cevap
One of the alternative DNA-sequence forms at a gene locus.
Kart 435
Soru
What is a gene locus?
Cevap
The physical position of a gene on a chromosome.
Kart 436
Soru
What is a genotype?
Cevap
The allele combination of an organism at one or more loci.
Kart 437
Soru
Which term describes a functional DNA sequence?
Cevap
a gene
Kart 438
Soru
Which term describes an alternative form of a gene?
Cevap
an allele
Kart 439
Soru
Which term describes a gene's chromosome position?
Cevap
a gene locus
Kart 440
Soru
Which term describes an organism's allele combination?
Cevap
a genotype
Kart 441
Soru
What is a phenotype?
Cevap
An observable or measurable trait produced by genotype and environment.
Kart 442
Soru
What is homozygous?
Cevap
Having two identical alleles at a diploid locus.
Kart 443
Soru
What is heterozygous?
Cevap
Having two different alleles at a diploid locus.
Kart 444
Soru
What is a dominant allele?
Cevap
An allele expressed in the phenotype of a heterozygote under a specified inheritance model.
Kart 445
Soru
Which term describes an observable trait resulting from genes and environment?
Cevap
a phenotype
Kart 446
Soru
Which term describes having two identical alleles at a locus?
Cevap
homozygous
Kart 447
Soru
Which term describes having two different alleles at a locus?
Cevap
heterozygous
Kart 448
Soru
Which term describes an allele expressed in a heterozygote?
Cevap
a dominant allele
Kart 449
Soru
What is a recessive allele?
Cevap
An allele whose phenotype is masked by a dominant allele in a heterozygote.
Kart 450
Soru
What is a genetic carrier?
Cevap
An unaffected heterozygote who can transmit a recessive disease allele.
Kart 451
Soru
What is a test cross?
Cevap
A cross with a homozygous recessive individual used to infer an unknown dominant phenotype's genotype.
Kart 452
Soru
What is a pedigree?
Cevap
A diagram showing biological relationships and occurrence of a trait across generations.
Kart 453
Soru
Which term describes an allele masked in a heterozygote?
Cevap
a recessive allele
Kart 454
Soru
Which term describes an unaffected heterozygote carrying a recessive disease allele?
Cevap
a genetic carrier
Kart 455
Soru
Which term describes a cross used to reveal an unknown dominant genotype?
Cevap
a test cross
Kart 456
Soru
Which term describes a family diagram tracking a trait across generations?
Cevap
a pedigree
Kart 457
Soru
What does allele segregation mean during gamete formation?
Cevap
The two alleles at a diploid locus separate so each gamete receives one.
Kart 458
Soru
What does a Punnett square predict?
Cevap
Expected genotype and phenotype probabilities from specified parental gametes, not guaranteed family outcomes.
Kart 459
Soru
What phenotypic ratio is expected from Aa × Aa with complete dominance?
Cevap
Approximately 3 dominant phenotype : 1 recessive phenotype.
Kart 460
Soru
What genotypic ratio is expected from Aa × Aa?
Cevap
1 AA : 2 Aa : 1 aa.
Kart 461
Soru
What happens in codominance?
Cevap
Both alleles contribute distinctly to the heterozygous phenotype.
Kart 462
Soru
What happens in incomplete dominance?
Cevap
The heterozygote has a phenotype intermediate between the two homozygotes.
Kart 463
Soru
How can environment affect phenotype without changing genotype?
Cevap
Conditions alter development, physiology, or gene expression, changing the observed trait.
Kart 464
Soru
What is the ultimate source of new alleles?
Cevap
Mutation.
Kart 465
Soru
Why are X-linked recessive traits more common in XY individuals?
Cevap
They have only one X chromosome, so one recessive allele on it can determine the phenotype.
Kart 466
Soru
When is the product rule used in genetic probability?
Cevap
For independent events that must both occur; multiply their probabilities.
Kart 467
Soru
When is the sum rule used in genetic probability?
Cevap
For mutually exclusive alternative outcomes; add their probabilities.
Kart 468
Soru
Why do polygenic traits often show continuous variation?
Cevap
Many loci contribute small effects, creating many possible genotypes and phenotypes, often further influenced by environment.
Kart 469
Soru
What pedigree pattern can suggest an autosomal recessive trait?
Cevap
Unaffected parents can have affected children, and all sexes are affected at similar frequencies.
Kart 470
Soru
What is a species?
Cevap
A group of organisms whose members can potentially interbreed and produce fertile offspring under natural conditions.
Kart 471
Soru
What is binomial nomenclature?
Cevap
The two-part scientific naming system using a genus name followed by a specific epithet.
Kart 472
Soru
What is taxonomy?
Cevap
The naming and classification of organisms.
Kart 473
Soru
What is a biological domain?
Cevap
The broadest commonly used taxonomic rank, separating Bacteria, Archaea, and Eukarya.
Kart 474
Soru
Which term describes a naturally interbreeding group producing fertile offspring?
Cevap
a species
Kart 475
Soru
Which term describes the genus-plus-specific-epithet naming system?
Cevap
binomial nomenclature
Kart 476
Soru
Which term describes the science of naming and classifying organisms?
Cevap
taxonomy
Kart 477
Soru
Which term describes the broadest common taxonomic rank?
Cevap
a biological domain
Kart 478
Soru
What is biodiversity?
Cevap
Variation of life at genetic, species, and ecosystem levels.
Kart 479
Soru
What is an autotroph?
Cevap
An organism that makes organic compounds from inorganic carbon using light or chemical energy.
Kart 480
Soru
What is a heterotroph?
Cevap
An organism that obtains organic carbon by consuming other organisms or their products.
960 kart
IB Biology SL Flashcards: Complete Course Review
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Kart 481
Soru
What is a unicellular organism?
Cevap
An organism consisting of one cell that carries out all essential life functions.
Kart 482
Soru
Which term describes variation of life across genes, species, and ecosystems?
Cevap
biodiversity
Kart 483
Soru
Which term describes an organism that builds organic matter from inorganic carbon?
Cevap
an autotroph
Kart 484
Soru
Which term describes an organism obtaining organic carbon from other organisms?
Cevap
a heterotroph
Kart 485
Soru
Which term describes an organism made of one cell?
Cevap
a unicellular organism
Kart 486
Soru
What is a multicellular organism?
Cevap
An organism composed of many cooperating cells, often with specialized cell types.
Kart 487
Soru
What is a karyotype?
Cevap
An ordered display of chromosomes used to examine their number and large-scale structure.
Kart 488
Soru
What broad feature distinguishes both Bacteria and Archaea from Eukarya?
Cevap
Their cells lack a nucleus and other membrane-bound organelles.
Kart 489
Soru
What features characterize most plant cells?
Cevap
Cellulose walls, chloroplasts in photosynthetic tissues, and large vacuoles are typical features.
Kart 490
Soru
Which term describes an organism made of many cooperating cells?
Cevap
a multicellular organism
Kart 491
Soru
Which term describes an ordered display of an individual's chromosomes?
Cevap
a karyotype
Kart 492
Soru
How do fungi obtain nutrients?
Cevap
They secrete digestive enzymes and absorb soluble products; their cells usually have chitin-containing walls.
Kart 493
Soru
What distinguishes animal nutrition and cell structure?
Cevap
Animals ingest organic material, and their cells lack cell walls and chloroplasts.
Kart 494
Soru
Why are scientific names useful across languages?
Cevap
A standardized name identifies the same organism internationally and reduces ambiguity from local common names.
Kart 495
Soru
Why can genetic diversity improve a population's resilience?
Cevap
More heritable variation increases the chance that some individuals tolerate new diseases or environmental changes.
Kart 496
Soru
What does ecosystem diversity measure?
Cevap
The variety of habitats, communities, and ecological processes within a region.
Kart 497
Soru
Why are Archaea classified separately from Bacteria?
Cevap
They differ in genetic sequences, membrane chemistry, cell-wall composition, and aspects of molecular machinery.
Kart 498
Soru
Why is the biological species concept difficult to apply to fossils or asexual organisms?
Cevap
Their ability to interbreed and produce fertile offspring cannot be tested in the usual way.
Kart 499
Soru
Does a larger chromosome number necessarily mean a more complex organism?
Cevap
No. Chromosome number varies through fusion, fission, and duplication and does not directly measure biological complexity.
Kart 500
Soru
Does genome size reliably predict organismal complexity?
Cevap
No. Large amounts of noncoding and repeated DNA make genome size a poor simple measure of complexity.
Kart 501
Soru
What evidence can be combined when classifying organisms?
Cevap
Molecular sequences, cell structure, anatomy, development, physiology, and reproductive evidence can all contribute.
Kart 502
Soru
What is gas exchange?
Cevap
Diffusion of respiratory gases between an organism and its environment or transport fluid.
Kart 503
Soru
What is ventilation?
Cevap
Bulk movement of air or water over a gas-exchange surface.
Kart 504
Soru
What is an alveolus?
Cevap
A microscopic air sac in the lung where gases diffuse between air and blood.
Kart 505
Soru
What is pulmonary surfactant?
Cevap
A substance lining alveoli that lowers surface tension and reduces collapse.
Kart 506
Soru
Which term describes diffusion of oxygen and carbon dioxide across a respiratory surface?
Cevap
gas exchange
Kart 507
Soru
Which term describes bulk movement of respiratory medium over an exchange surface?
Cevap
ventilation
Kart 508
Soru
Which term describes a microscopic lung air sac?
Cevap
an alveolus
Kart 509
Soru
Which term describes the alveolar lining that lowers surface tension?
Cevap
pulmonary surfactant
Kart 510
Soru
What is the diaphragm?
Cevap
A sheet of skeletal muscle whose contraction increases thoracic volume during inhalation.
Kart 511
Soru
What is tidal volume?
Cevap
The volume of air moved in or out during a normal breath.
Kart 512
Soru
What is a stoma?
Cevap
A regulated epidermal pore through which gases diffuse in leaves.
Kart 513
Soru
What is countercurrent exchange?
Cevap
Exchange between fluids moving in opposite directions, maintaining a gradient along most of the surface.
Kart 514
Soru
Which term describes the muscle sheet that expands the thorax during inhalation?
Cevap
the diaphragm
Kart 515
Soru
Which term describes air volume moved in one normal breath?
Cevap
tidal volume
Kart 516
Soru
Which term describes a regulated leaf gas-exchange pore?
Cevap
a stoma
Kart 517
Soru
Which term describes opposite fluid flow that maintains an exchange gradient?
Cevap
countercurrent exchange
Kart 518
Soru
What features make an efficient gas-exchange surface?
Cevap
Large area, short diffusion distance, permeability, and maintained concentration gradients.
Kart 519
Soru
How is a steep oxygen gradient maintained across alveoli?
Cevap
Ventilation replenishes alveolar oxygen and blood flow removes absorbed oxygen.
Kart 520
Soru
How does diaphragm contraction cause inhalation?
Cevap
Thoracic volume increases, lung pressure falls below atmospheric pressure, and air flows inward.
Kart 521
Soru
What drives quiet exhalation?
Cevap
The diaphragm relaxes and elastic recoil reduces thoracic and lung volume, raising pressure and pushing air out.
Kart 522
Soru
Why do ventilation rate and depth increase during exercise?
Cevap
They increase oxygen uptake and carbon dioxide removal to support higher cellular respiration.
Kart 523
Soru
How does leaf structure shorten the pathway for carbon dioxide diffusion?
Cevap
Stomata open into air spaces, and mesophyll cells expose moist surfaces close to those spaces.
Kart 524
Soru
Why does carbon dioxide diffuse from tissues into blood?
Cevap
Respiring cells produce carbon dioxide, making its partial pressure higher in tissues than in incoming blood.
Kart 525
Soru
How does countercurrent flow improve oxygen uptake at fish gills?
Cevap
Blood continually meets water with a higher oxygen concentration, preserving diffusion along the lamella.
Kart 526
Soru
Why does closing stomata reduce both water loss and photosynthesis?
Cevap
It limits water-vapor diffusion out but also restricts carbon dioxide diffusion into the leaf.
Kart 527
Soru
What is a circulatory system?
Cevap
A transport system that moves a fluid carrying gases, nutrients, wastes, hormones, and heat through an organism.
Kart 528
Soru
What is an artery?
Cevap
A blood vessel carrying blood away from the heart under relatively high pressure.
Kart 529
Soru
What is a vein?
Cevap
A blood vessel carrying blood toward the heart, usually with low pressure and often valves.
Kart 530
Soru
What is a capillary?
Cevap
A microscopic thin-walled vessel where substances exchange between blood and tissues.
Kart 531
Soru
Which term describes an internal fluid-transport system?
Cevap
a circulatory system
Kart 532
Soru
Which term describes a vessel carrying blood away from the heart?
Cevap
an artery
Kart 533
Soru
Which term describes a vessel carrying blood toward the heart?
Cevap
a vein
Kart 534
Soru
Which term describes a microscopic exchange blood vessel?
Cevap
a capillary
Kart 535
Soru
What is the cardiac cycle?
Cevap
The repeating sequence of heart-chamber contraction and relaxation that pumps blood.
Kart 536
Soru
What is hemoglobin?
Cevap
An iron-containing protein in red blood cells that binds oxygen reversibly.
Kart 537
Soru
What is xylem?
Cevap
Plant vascular tissue that transports water and mineral ions and provides structural support.
Kart 538
Soru
What is phloem?
Cevap
Plant vascular tissue that transports sucrose and other organic solutes between sources and sinks.
Kart 539
Soru
Which term describes the repeating pumping sequence of the heart?
Cevap
the cardiac cycle
Kart 540
Soru
Which term describes the oxygen-carrying protein of red blood cells?
Cevap
hemoglobin
Kart 541
Soru
Which term describes plant tissue carrying water and minerals?
Cevap
xylem
Kart 542
Soru
Which term describes plant tissue carrying organic solutes?
Cevap
phloem
Kart 543
Soru
What is transpiration?
Cevap
Loss of water vapor from plant surfaces, mainly through stomata.
Kart 544
Soru
What is phloem translocation?
Cevap
Movement of organic solutes through phloem from sources to sinks.
Kart 545
Soru
How do a source and a sink differ in plant transport?
Cevap
A source releases assimilates to phloem; a sink removes them for use or storage.
Kart 546
Soru
What makes human circulation a double circulation?
Cevap
Blood passes through the heart once in the pulmonary circuit and again in the systemic circuit during one complete journey.
Kart 547
Soru
Which term describes water-vapor loss from plant surfaces?
Cevap
transpiration
Kart 548
Soru
Which term describes movement of organic solutes through phloem?
Cevap
phloem translocation
Kart 549
Soru
Which term describes the exporting and importing regions of phloem transport?
Cevap
source and sink
Kart 550
Soru
How is an artery adapted to high pressure?
Cevap
It has thick elastic and muscular walls and a relatively narrow lumen.
Kart 551
Soru
How is a vein adapted to return low-pressure blood?
Cevap
It has a wide lumen, thinner walls, and valves that reduce backflow.
Kart 552
Soru
How does capillary structure support exchange?
Cevap
One-cell-thick walls give a short diffusion distance; extensive branching gives a large total area; narrow lumens slow flow and keep blood close to tissues.
Kart 553
Soru
What determines whether a heart valve opens or closes?
Cevap
Pressure differences across the valve.
Kart 554
Soru
Trace water from soil to the atmosphere through a plant.
Cevap
Soil → root hairs → root tissues → xylem → leaf mesophyll → leaf air spaces → stomata → atmosphere.
Kart 555
Soru
Why may root cells use active transport to absorb mineral ions?
Cevap
Ion concentrations can be lower in soil than in root cells, so uptake must occur against a gradient.
Kart 556
Soru
Why do large multicellular organisms need bulk transport systems?
Cevap
Their low surface-area-to-volume ratio and long diffusion distances make diffusion alone too slow for whole-body supply.
Kart 557
Soru
Why does hemoglobin unload more oxygen in actively respiring tissues?
Cevap
Lower oxygen and often higher carbon dioxide and acidity reduce hemoglobin's oxygen affinity.
Kart 558
Soru
How does transpiration pull water upward through xylem?
Cevap
Evaporation lowers leaf water potential and creates tension; cohesion transmits the pull through the continuous water column.
Kart 559
Soru
How do wind and low humidity generally affect transpiration?
Cevap
Both maintain a steep water-vapor gradient outside the leaf, increasing transpiration if stomata remain open.
Kart 560
Soru
What drives mass flow in phloem?
Cevap
Sugar loading draws in water and raises pressure at a source; unloading lowers pressure at a sink, producing bulk flow.
Kart 561
Soru
Can the same plant organ be a source at one time and a sink at another?
Cevap
Yes. A storage organ may import sugars while filling and export them later during growth or germination.
Kart 562
Soru
What is a neuron?
Cevap
An excitable cell specialized to receive, process, and transmit information.
Kart 563
Soru
What is a sensory neuron?
Cevap
A neuron carrying information from a receptor toward the central nervous system.
Kart 564
Soru
What is a motor neuron?
Cevap
A neuron carrying commands from the central nervous system to an effector.
Kart 565
Soru
What is the resting potential?
Cevap
The voltage difference across an unstimulated neuron's membrane, with the inside negative relative to outside.
Kart 566
Soru
Which term describes an excitable information-transmitting cell?
Cevap
a neuron
Kart 567
Soru
Which term describes a neuron carrying receptor information to the CNS?
Cevap
a sensory neuron
Kart 568
Soru
Which term describes a neuron carrying CNS commands to an effector?
Cevap
a motor neuron
Kart 569
Soru
Which term describes the negative-inside voltage of an unstimulated neuron?
Cevap
the resting potential
Kart 570
Soru
What is an action potential?
Cevap
A brief, self-propagating reversal and restoration of membrane potential along an excitable membrane.
Kart 571
Soru
What is depolarization?
Cevap
A change that makes membrane potential less negative, and during an action potential often positive.
Kart 572
Soru
What is repolarization?
Cevap
Return of membrane potential toward its resting negative value after depolarization.
Kart 573
Soru
What is a synapse?
Cevap
A junction where one cell communicates with another cell.
Kart 574
Soru
Which term describes a brief propagating change in neuron membrane voltage?
Cevap
an action potential
Kart 575
Soru
Which term describes a membrane-voltage change toward a less negative value?
Cevap
depolarization
Kart 576
Soru
Which term describes return toward resting membrane voltage?
Cevap
repolarization
Kart 577
Soru
Which term describes a communication junction between cells?
Cevap
a synapse
Kart 578
Soru
What is a neurotransmitter?
Cevap
A chemical released by a neuron that changes the activity of a target cell.
Kart 579
Soru
What is the refractory period?
Cevap
A brief period after an action potential when another is impossible or requires a stronger stimulus.
Kart 580
Soru
What is myelin?
Cevap
An insulating sheath around some axons that speeds impulse conduction.
Kart 581
Soru
What happens when membrane depolarization reaches threshold?
Cevap
Voltage-gated channels trigger the self-amplifying events of an action potential.
Kart 582
Soru
Which term describes a neuron-released signaling chemical?
Cevap
a neurotransmitter
Kart 583
Soru
Which term describes the recovery interval after an action potential?
Cevap
the refractory period
Kart 584
Soru
Which term describes the insulating axon sheath?
Cevap
myelin
Kart 585
Soru
What does the all-or-none principle mean for an action potential?
Cevap
Once threshold is reached, the action potential has a characteristic size; stronger stimuli increase frequency, not its amplitude.
Kart 586
Soru
How does myelin increase conduction speed?
Cevap
Depolarizing current travels rapidly beneath myelin and action potentials regenerate mainly at gaps in the sheath.
Kart 587
Soru
What is the basic sequence at a chemical synapse?
Cevap
An impulse triggers neurotransmitter release; it diffuses across the cleft, binds receptors, and alters the postsynaptic cell.
Kart 588
Soru
Why can a reflex response be rapid?
Cevap
A short neural pathway produces an automatic response without waiting for conscious processing.
Kart 589
Soru
What is sensory transduction?
Cevap
Conversion of a physical or chemical stimulus into an electrical signal in a receptor cell.
Kart 590
Soru
How does an action potential propagate along an axon?
Cevap
Local current depolarizes the next membrane region to threshold, opening voltage-gated channels there.
Kart 591
Soru
Why does an action potential normally travel in one direction along an axon?
Cevap
The membrane just behind it is refractory and cannot immediately fire again.
Kart 592
Soru
How is neurotransmitter action ended?
Cevap
The transmitter is removed by enzymatic breakdown, reuptake, or diffusion away.
Kart 593
Soru
What is sensory adaptation?
Cevap
Reduced receptor or neural response during a constant, unchanging stimulus.
Kart 594
Soru
How can a drug alter synaptic transmission?
Cevap
It may mimic or block a transmitter, change its release, or change its removal from the synaptic cleft.
Kart 595
Soru
What is an organ system?
Cevap
A group of organs coordinating to perform major functions for an organism.
Kart 596
Soru
What is a hormone?
Cevap
A signaling molecule released into transport fluid and acting on target cells with suitable receptors.
Kart 597
Soru
What is an endocrine gland?
Cevap
A gland that secretes hormones into extracellular fluid and blood rather than through a duct.
Kart 598
Soru
What is a hormone target cell?
Cevap
A cell able to respond because it has the appropriate receptor.
Kart 599
Soru
Which term describes a coordinated group of organs?
Cevap
an organ system
Kart 600
Soru
Which term describes a long-distance chemical messenger carried in body fluid?
Cevap
a hormone
Kart 601
Soru
Which term describes a ductless hormone-secreting gland?
Cevap
an endocrine gland
Kart 602
Soru
Which term describes a cell with a receptor for a particular hormone?
Cevap
a hormone target cell
Kart 603
Soru
What is digestion?
Cevap
Mechanical and chemical breakdown of food into molecules small enough to absorb.
Kart 604
Soru
What is absorption?
Cevap
Movement of digested nutrients across an exchange surface into blood or lymph.
Kart 605
Soru
What is peristalsis?
Cevap
Coordinated waves of smooth-muscle contraction that move material through the digestive tract.
Kart 606
Soru
What is an intestinal villus?
Cevap
A finger-like projection increasing the absorptive surface of the small intestine.
Kart 607
Soru
Which term describes breakdown of food into absorbable molecules?
Cevap
digestion
Kart 608
Soru
Which term describes movement of digested nutrients into transport fluids?
Cevap
absorption
Kart 609
Soru
Which term describes wave-like gut contractions moving contents?
Cevap
peristalsis
Kart 610
Soru
Which term describes a finger-like intestinal absorption projection?
Cevap
an intestinal villus
Kart 611
Soru
What is excretion?
Cevap
Removal of metabolic waste products from the body.
Kart 612
Soru
What is a nephron?
Cevap
The microscopic functional unit of the kidney that filters blood and modifies filtrate into urine.
Kart 613
Soru
What is ultrafiltration?
Cevap
Pressure-driven filtration of small molecules from blood into a kidney capsule while cells and most proteins remain in blood.
Kart 614
Soru
What is selective reabsorption?
Cevap
Recovery of useful substances and regulated amounts of water and ions from kidney filtrate into blood.
Kart 615
Soru
Which term describes removal of metabolic wastes?
Cevap
excretion
Kart 616
Soru
Which term describes the kidney's microscopic functional unit?
Cevap
a nephron
Kart 617
Soru
Which term describes pressure filtration at the start of a nephron?
Cevap
ultrafiltration
Kart 618
Soru
Which term describes return of useful substances from kidney filtrate to blood?
Cevap
selective reabsorption
Kart 619
Soru
What is skeletal muscle?
Cevap
Striated voluntary muscle attached to the skeleton and used for movement and posture.
Kart 620
Soru
What is an antagonistic muscle pair?
Cevap
Two muscles producing opposite movements at a joint because muscles pull but do not push.
Kart 621
Soru
How do nervous and endocrine signaling generally differ?
Cevap
Neural signals are rapid and targeted; hormonal signals are usually slower, longer-lasting, and distributed through body fluids.
Kart 622
Soru
Why does a circulating hormone affect only some cells?
Cevap
Only target cells express receptors that recognize the hormone and activate a response.
Kart 623
Soru
Which term describes voluntary striated muscle that moves the skeleton?
Cevap
skeletal muscle
Kart 624
Soru
Which term describes two muscles producing opposite joint movements?
Cevap
an antagonistic muscle pair
Kart 625
Soru
What is the final absorbable product of most dietary carbohydrate digestion?
Cevap
Monosaccharides, especially glucose.
Kart 626
Soru
What are the main absorbable products of protein digestion?
Cevap
Amino acids and small peptides that are completed to amino acids during absorption.
Kart 627
Soru
How is the small intestine adapted for absorption?
Cevap
Folds, villi, and microvilli increase area; a thin epithelium, rich blood supply, and lymph vessels support transport.
Kart 628
Soru
Name three integrative roles of the liver.
Cevap
It processes absorbed nutrients, regulates blood chemistry, detoxifies substances, produces bile, and converts ammonia to urea; any three are sufficient.
Kart 629
Soru
Why are blood cells and most plasma proteins absent from normal kidney filtrate?
Cevap
They are too large to cross the filtration barrier.
Kart 630
Soru
How do muscles move a bone at a joint?
Cevap
Contraction shortens the muscle, pulling through a tendon on the bone.
Kart 631
Soru
Why are antagonistic muscles needed at many joints?
Cevap
A muscle can pull in one direction but cannot push itself back, so an opposing muscle produces the reverse movement.
Kart 632
Soru
Why must organ systems be integrated rather than acting independently?
Cevap
Each system depends on materials, signals, waste removal, and stable conditions supplied by other systems.
Kart 633
Soru
Why do many absorbed lipids enter lymph before blood?
Cevap
Intestinal cells package them into lipoprotein particles too large to enter ordinary blood capillaries directly.
Kart 634
Soru
Why is glucose normally absent from final urine?
Cevap
Filtered glucose is selectively reabsorbed into blood when transporter capacity is not exceeded.
Kart 635
Soru
How do respiratory, circulatory, and muscular systems cooperate during exercise?
Cevap
Ventilation supplies oxygen, circulation transports gases and fuels, and muscles use ATP while returning carbon dioxide, heat, and metabolites.
Kart 636
Soru
How do liver, circulation, and kidneys cooperate in nitrogen-waste removal?
Cevap
The liver converts toxic ammonia to urea, blood carries urea, and kidneys filter and excrete it.
Kart 637
Soru
What is a pathogen?
Cevap
A biological agent capable of causing disease.
Kart 638
Soru
What is an antigen?
Cevap
A molecule recognized specifically by an antibody or lymphocyte receptor.
Kart 639
Soru
What is innate immunity?
Cevap
Rapid, nonspecific defense mechanisms present without prior exposure.
Kart 640
Soru
What is adaptive immunity?
Cevap
Specific defense that develops through lymphocyte activation and can form memory.
Kart 641
Soru
Which term describes a disease-causing biological agent?
Cevap
a pathogen
Kart 642
Soru
Which term describes a molecule specifically recognized by adaptive immune receptors?
Cevap
an antigen
Kart 643
Soru
Which term describes rapid nonspecific immune defense?
Cevap
innate immunity
Kart 644
Soru
Which term describes specific immune defense capable of memory?
Cevap
adaptive immunity
Kart 645
Soru
What is a phagocyte?
Cevap
A cell that engulfs and digests microbes, particles, or damaged cells.
Kart 646
Soru
What is a lymphocyte?
Cevap
An adaptive immune cell with receptors specific to particular antigens.
Kart 647
Soru
What is an antibody?
Cevap
A secreted immunoglobulin that binds a specific antigen.
Kart 648
Soru
What is a B lymphocyte?
Cevap
A lymphocyte that can differentiate into antibody-secreting plasma cells and memory cells.
Kart 649
Soru
Which term describes an engulfing immune cell?
Cevap
a phagocyte
Kart 650
Soru
Which term describes an antigen-specific adaptive immune cell?
Cevap
a lymphocyte
Kart 651
Soru
Which term describes a secreted antigen-binding immunoglobulin?
Cevap
an antibody
Kart 652
Soru
Which term describes the lymphocyte lineage that produces antibody-secreting cells?
Cevap
a B lymphocyte
Kart 653
Soru
What is a helper T cell?
Cevap
A lymphocyte that coordinates immune responses through contact signals and cytokines.
Kart 654
Soru
What is an immune memory cell?
Cevap
A long-lived lymphocyte that responds rapidly after re-exposure to its antigen.
Kart 655
Soru
What is vaccination?
Cevap
Deliberate exposure to a safe form or component of an antigen to generate protective immune memory.
Kart 656
Soru
What is an antibiotic?
Cevap
A substance that kills bacteria or inhibits their growth at clinically useful doses.
Kart 657
Soru
Which term describes the T cell that coordinates other immune cells?
Cevap
a helper T cell
Kart 658
Soru
Which term describes a long-lived lymphocyte enabling faster re-exposure response?
Cevap
an immune memory cell
Kart 659
Soru
Which term describes safe antigen exposure used to create immune memory?
Cevap
vaccination
Kart 660
Soru
Which term describes a drug acting against bacteria?
Cevap
an antibiotic
Kart 661
Soru
What are examples of first-line defenses against pathogens?
Cevap
Intact skin, mucus, cilia, antimicrobial secretions, stomach acidity, and competing microbiota.
Kart 662
Soru
How does inflammation help defend damaged tissue?
Cevap
It increases local blood flow and vessel permeability and recruits immune cells and defensive molecules.
Kart 663
Soru
What happens during phagocytosis?
Cevap
A cell surrounds a particle in a vesicle, then fuses it with digestive compartments to destroy or process it.
Kart 664
Soru
How can antibodies help eliminate a pathogen?
Cevap
They can neutralize targets, block attachment, clump particles, and mark them for phagocytosis or complement attack.
Kart 665
Soru
Why can a vaccine generate protection without causing the full disease?
Cevap
It presents antigen in a weakened, inactivated, partial, or encoded form that stimulates immunity with much lower risk.
Kart 666
Soru
Why do antibiotics not treat viral infections?
Cevap
Viruses lack the bacterial structures and independent metabolic processes targeted by antibiotics.
Kart 667
Soru
What determines the antigen specificity of a lymphocyte?
Cevap
The molecular shape and chemistry of its unique surface receptor.
Kart 668
Soru
What is clonal selection?
Cevap
An antigen activates lymphocytes with matching receptors, causing them to proliferate and differentiate.
Kart 669
Soru
Why is a secondary adaptive immune response usually faster and stronger?
Cevap
Memory cells are more numerous and activate rapidly, producing effective cells and antibodies sooner.
Kart 670
Soru
How can high vaccination coverage protect some unvaccinated people?
Cevap
Reduced transmission makes encounters with infectious individuals less likely, though protection is incomplete and pathogen-dependent.
Kart 671
Soru
How does antibiotic use select for resistant bacteria?
Cevap
Susceptible bacteria are removed while resistant variants survive and reproduce, increasing resistance-allele frequency.
Kart 672
Soru
Why can unnecessary or incomplete antibiotic exposure promote resistance?
Cevap
It creates selection favoring resistant cells while potentially leaving surviving bacteria to multiply and spread.
Kart 673
Soru
What is an allergy?
Cevap
An immune response to a normally harmless antigen that causes tissue symptoms or damage.
Kart 674
Soru
What is asexual reproduction?
Cevap
Production of offspring from one parent without fusion of gametes.
Kart 675
Soru
What is sexual reproduction?
Cevap
Production of offspring involving fusion of haploid gametes.
Kart 676
Soru
What is a gamete?
Cevap
A haploid reproductive cell able to fuse with another gamete.
Kart 677
Soru
What is fertilization?
Cevap
Fusion of gamete nuclei to form a diploid zygote.
Kart 678
Soru
Which term describes reproduction without gamete fusion?
Cevap
asexual reproduction
Kart 679
Soru
Which term describes reproduction involving gamete fusion?
Cevap
sexual reproduction
Kart 680
Soru
Which term describes a haploid reproductive cell?
Cevap
a gamete
Kart 681
Soru
Which term describes fusion of gamete nuclei?
Cevap
fertilization
Kart 682
Soru
What is a zygote?
Cevap
The diploid cell formed by fertilization.
Kart 683
Soru
What is meiosis?
Cevap
Cell division that halves chromosome number and usually produces genetically varied haploid cells.
Kart 684
Soru
What is ovulation?
Cevap
Release of a secondary oocyte from an ovary.
Kart 685
Soru
What is implantation?
Cevap
Attachment and embedding of an early embryo in the uterine lining.
Kart 686
Soru
Which term describes the first diploid cell after fertilization?
Cevap
a zygote
Kart 687
Soru
Which term describes division producing varied haploid cells?
Cevap
meiosis
Kart 688
Soru
Which term describes release of an oocyte from an ovary?
Cevap
ovulation
Kart 689
Soru
Which term describes embedding of an early embryo in the uterine lining?
Cevap
implantation
Kart 690
Soru
What is the placenta?
Cevap
A temporary organ that exchanges materials between maternal and fetal blood supplies without normally mixing them directly.
Kart 691
Soru
What is pollination?
Cevap
Transfer of pollen from an anther to a receptive stigma.
Kart 692
Soru
Why does sexual reproduction usually produce more genetic variation than asexual reproduction?
Cevap
Meiosis reshuffles alleles and random fertilization combines genomes from two gametes.
Kart 693
Soru
Why must gametes be haploid?
Cevap
Fusion of two haploid gametes restores the diploid chromosome number instead of doubling it each generation.
Kart 694
Soru
Which term describes the maternal-fetal exchange organ?
Cevap
the placenta
Kart 695
Soru
Which term describes transfer of pollen to a stigma?
Cevap
pollination
Kart 696
Soru
What are major roles of FSH in the ovarian cycle?
Cevap
It stimulates follicle development and supports estrogen secretion.
Kart 697
Soru
What is a major role of the mid-cycle LH surge?
Cevap
It triggers ovulation and formation of the corpus luteum.
Kart 698
Soru
How does estrogen contribute to the uterine cycle?
Cevap
It promotes repair and thickening of the uterine lining after menstruation.
Kart 699
Soru
How does progesterone contribute to the uterine cycle?
Cevap
It maintains a thick, secretory uterine lining after ovulation.
Kart 700
Soru
Where does human fertilization usually occur?
Cevap
In an oviduct, before the early embryo reaches the uterus.
Kart 701
Soru
What happens after compatible pollen reaches a flower's stigma?
Cevap
A pollen tube grows toward an ovule and delivers male nuclei for fertilization.
Kart 702
Soru
Why does menstruation usually begin if pregnancy does not occur?
Cevap
The corpus luteum degenerates, progesterone and estrogen fall, and the uterine lining is no longer maintained.
Kart 703
Soru
What substances commonly cross the placenta between mother and fetus?
Cevap
Oxygen and nutrients move toward the fetus; carbon dioxide and nitrogenous wastes move toward the mother.
Kart 704
Soru
How can contraception prevent pregnancy in different ways?
Cevap
Methods can inhibit ovulation, block sperm from reaching an egg, prevent fertilization, or permanently interrupt the reproductive ducts.
Kart 705
Soru
What is homeostasis?
Cevap
Maintenance of internal conditions within ranges compatible with normal function despite change.
Kart 706
Soru
What is negative feedback?
Cevap
Control in which a deviation triggers responses that oppose the original change.
Kart 707
Soru
What is a set point?
Cevap
The target value or range around which a regulated variable is maintained.
Kart 708
Soru
What is a homeostatic receptor?
Cevap
A sensor that detects a change in a regulated variable.
Kart 709
Soru
Which term describes maintenance of a stable functional internal environment?
Cevap
homeostasis
Kart 710
Soru
Which term describes feedback that counteracts a deviation?
Cevap
negative feedback
Kart 711
Soru
Which term describes the target around which a variable is regulated?
Cevap
a set point
Kart 712
Soru
Which term describes the sensor in a feedback system?
Cevap
a homeostatic receptor
Kart 713
Soru
What is a control center?
Cevap
The component that compares information with a target and coordinates a response.
Kart 714
Soru
What is an effector?
Cevap
A muscle, gland, or other component that carries out a control response.
Kart 715
Soru
What is thermoregulation?
Cevap
Control of body temperature within a functional range.
Kart 716
Soru
What is vasodilation?
Cevap
Widening of blood vessels, often increasing blood flow near the skin.
Kart 717
Soru
Which term describes the feedback component that evaluates input and directs a response?
Cevap
a control center
Kart 718
Soru
Which term describes the component that executes a physiological response?
Cevap
an effector
Kart 719
Soru
Which term describes physiological regulation of body temperature?
Cevap
thermoregulation
Kart 720
Soru
Which term describes widening of blood vessels?
Cevap
vasodilation
Kart 721
Soru
What is vasoconstriction?
Cevap
Narrowing of blood vessels, often reducing blood flow near the skin.
Kart 722
Soru
What is insulin?
Cevap
A pancreatic hormone that lowers elevated blood glucose by promoting uptake and storage.
Kart 723
Soru
What is glucagon?
Cevap
A pancreatic hormone that raises low blood glucose by promoting release of stored fuel.
Kart 724
Soru
What are the main components of a homeostatic feedback loop?
Cevap
A regulated variable, receptor, control center, effectors, and responses that alter the variable.
Kart 725
Soru
Which term describes narrowing of blood vessels?
Cevap
vasoconstriction
Kart 726
Soru
Which term describes the pancreatic hormone that lowers blood glucose?
Cevap
insulin
Kart 727
Soru
Which term describes the pancreatic hormone that raises blood glucose?
Cevap
glucagon
Kart 728
Soru
What happens when blood glucose rises after a meal?
Cevap
Insulin secretion increases, promoting glucose uptake and storage so blood glucose falls toward its normal range.
Kart 729
Soru
What happens when blood glucose falls during fasting?
Cevap
Glucagon secretion increases, promoting glycogen breakdown and glucose release by the liver.
Kart 730
Soru
How does sweating cool the body?
Cevap
Evaporation of water from skin transfers heat to the environment.
Kart 731
Soru
How does skin vasodilation increase heat loss?
Cevap
It brings more warm blood near the surface, increasing transfer of heat to the environment.
Kart 732
Soru
How does shivering warm the body?
Cevap
Rapid involuntary muscle contractions increase respiration and heat production.
Kart 733
Soru
Does homeostasis keep internal conditions perfectly constant?
Cevap
No. Variables fluctuate within controlled ranges around target values.
Kart 734
Soru
How does ADH help conserve water?
Cevap
It increases water permeability in kidney collecting ducts, so more water is reabsorbed and urine becomes more concentrated.
Kart 735
Soru
How should ADH secretion change during dehydration?
Cevap
It should increase, promoting greater water reabsorption by the kidneys.
Kart 736
Soru
How does positive feedback differ from negative feedback?
Cevap
Positive feedback amplifies a change until an endpoint; negative feedback opposes a change and stabilizes a variable.
Kart 737
Soru
Why can diabetes mellitus cause persistently high blood glucose?
Cevap
Insulin production may be insufficient or target cells may respond poorly to insulin.
Kart 738
Soru
What is biological evolution?
Cevap
Change in heritable characteristics or allele frequencies of a population across generations.
Kart 739
Soru
What is allele frequency?
Cevap
The proportion of gene copies in a population represented by a particular allele.
Kart 740
Soru
What is microevolution?
Cevap
Evolutionary change in allele frequencies within populations over relatively short timescales.
Kart 741
Soru
What is speciation?
Cevap
Evolutionary formation of new species.
Kart 742
Soru
Which term describes change in a population's heritable composition across generations?
Cevap
biological evolution
Kart 743
Soru
Which term describes the proportion of a population's gene copies that are one allele?
Cevap
allele frequency
Kart 744
Soru
Which term describes short-timescale allele-frequency change within populations?
Cevap
microevolution
Kart 745
Soru
Which term describes formation of new species?
Cevap
speciation
Kart 746
Soru
What is reproductive isolation?
Cevap
Barriers that prevent or greatly reduce gene flow between populations.
Kart 747
Soru
What is allopatric speciation?
Cevap
Speciation after populations become geographically separated and diverge.
Kart 748
Soru
What is sympatric speciation?
Cevap
Speciation without geographic separation, through reproductive isolation within the same area.
Kart 749
Soru
What are homologous structures?
Cevap
Structures similar because they were inherited from a common ancestor, even if their functions differ.
Kart 750
Soru
Which term describes barriers reducing gene flow between populations?
Cevap
reproductive isolation
Kart 751
Soru
Which term describes speciation following geographic separation?
Cevap
allopatric speciation
Kart 752
Soru
Which term describes speciation within the same geographic area?
Cevap
sympatric speciation
Kart 753
Soru
Which term describes structures similar through common ancestry?
Cevap
homologous structures
Kart 754
Soru
What are analogous structures?
Cevap
Structures with similar functions that evolved independently rather than from the same ancestral structure.
Kart 755
Soru
What is a common ancestor?
Cevap
An ancestral population from which two or more descendant lineages evolved.
Kart 756
Soru
How does the fossil record provide evidence for evolution?
Cevap
It documents organisms from different times, including appearance, change, persistence, and extinction of lineages.
Kart 757
Soru
How do DNA and protein sequences provide evidence of common ancestry?
Cevap
Shared sequences are inherited; greater similarity generally indicates more recent common ancestry.
Kart 758
Soru
Which term describes functionally similar structures of independent evolutionary origin?
Cevap
analogous structures
Kart 759
Soru
Which term describes an ancestral population shared by descendant lineages?
Cevap
a common ancestor
Kart 760
Soru
What is the evolutionary significance of extinction?
Cevap
It permanently ends a lineage and can alter ecological opportunities and the future diversification of survivors.
Kart 761
Soru
Do individual organisms evolve during their lifetimes?
Cevap
No. Individuals develop and acclimate; evolution is heritable change in populations across generations.
Kart 762
Soru
Why is evolution represented as a branching tree rather than a ladder?
Cevap
Lineages split from common ancestors; living species are not arranged as stages toward a single goal.
Kart 763
Soru
How can island species support evolutionary explanations?
Cevap
Their similarities to nearby mainland ancestors and unique local adaptations fit divergence after colonization and isolation.
Kart 764
Soru
How can geographic isolation lead to reproductive isolation?
Cevap
Separated populations accumulate different mutations and experience different selection and drift until interbreeding is reduced.
Kart 765
Soru
Why can continuing gene flow slow speciation?
Cevap
Movement of alleles between populations counteracts genetic divergence.
Kart 766
Soru
Why can unrelated species evolve similar traits?
Cevap
Similar environmental challenges can favor similar functional solutions through convergent evolution.
Kart 767
Soru
Which parts of evolution are random and which are nonrandom?
Cevap
Mutation and many sampling effects are random with respect to need; natural selection nonrandomly favors variants that reproduce better in a given environment.
Kart 768
Soru
What is conservation biology?
Cevap
The science and practice of protecting biodiversity, ecological processes, and evolutionary potential.
Kart 769
Soru
What is habitat fragmentation?
Cevap
Division of continuous habitat into smaller, isolated patches.
Kart 770
Soru
What is an endangered species?
Cevap
A species facing a high risk of extinction in the wild.
Kart 771
Soru
What is in situ conservation?
Cevap
Protection of species in their natural habitats and ecological communities.
Kart 772
Soru
Which term describes the protection of biodiversity and ecological processes?
Cevap
conservation biology
Kart 773
Soru
Which term describes division of habitat into isolated patches?
Cevap
habitat fragmentation
Kart 774
Soru
Which term describes a species at high risk of extinction?
Cevap
an endangered species
Kart 775
Soru
Which term describes conservation within natural habitat?
Cevap
in situ conservation
Kart 776
Soru
What is ex situ conservation?
Cevap
Protection of organisms or genetic material outside the natural habitat.
Kart 777
Soru
What is a population bottleneck?
Cevap
A sharp population reduction that can remove genetic variation by chance.
Kart 778
Soru
What is a wildlife corridor?
Cevap
Habitat connecting isolated patches to permit movement and gene flow.
Kart 779
Soru
What major human-driven processes threaten biodiversity?
Cevap
Habitat loss, overexploitation, invasive species, pollution, and climate change.
Kart 780
Soru
Which term describes conservation outside natural habitat?
Cevap
ex situ conservation
Kart 781
Soru
Which term describes a severe population reduction that loses genetic diversity?
Cevap
a population bottleneck
Kart 782
Soru
Which term describes habitat linking isolated populations?
Cevap
a wildlife corridor
Kart 783
Soru
What makes a protected area more effective than a boundary alone?
Cevap
Adequate size, representative habitat, enforcement, connectivity, local support, and management of external threats.
Kart 784
Soru
Why is long-term population monitoring important in conservation?
Cevap
It reveals trends, tests whether management works, and provides early warning of decline.
Kart 785
Soru
How can ecosystem services support the case for conservation?
Cevap
Healthy ecosystems provide benefits such as pollination, water purification, carbon storage, soil formation, and cultural value.
Kart 786
Soru
Why are very small populations especially vulnerable to extinction?
Cevap
Chance events, inbreeding, low genetic diversity, and difficulty finding mates can reinforce decline.
Kart 787
Soru
What are benefits and limits of captive-breeding programs?
Cevap
They can prevent immediate extinction and manage breeding, but may lose diversity, alter behavior, and fail without safe habitat for release.
Kart 788
Soru
Why can controlling an invasive species aid conservation?
Cevap
It can reduce predation, competition, disease, or habitat alteration affecting native species.
Kart 789
Soru
Why must conservation priorities consider more than species count?
Cevap
Endemism, evolutionary distinctness, ecological roles, threat severity, feasibility, and human needs also matter.
Kart 790
Soru
What is an adaptation?
Cevap
A heritable characteristic that increases reproductive success in a particular environment.
Kart 791
Soru
What is acclimation?
Cevap
A reversible physiological or behavioral adjustment by an individual to environmental change.
Kart 792
Soru
What is a structural adaptation?
Cevap
An inherited anatomical feature that improves performance in an environment.
Kart 793
Soru
What is a physiological adaptation?
Cevap
An inherited functional or biochemical feature that improves performance in an environment.
Kart 794
Soru
Which term describes a heritable trait improving reproductive success in context?
Cevap
an adaptation
Kart 795
Soru
Which term describes an individual's reversible adjustment to environmental change?
Cevap
acclimation
Kart 796
Soru
Which term describes an adaptive anatomical feature?
Cevap
a structural adaptation
Kart 797
Soru
Which term describes an adaptive functional or biochemical feature?
Cevap
a physiological adaptation
Kart 798
Soru
What is a behavioral adaptation?
Cevap
An inherited behavior pattern that improves survival or reproduction.
Kart 799
Soru
What is an environmental tolerance range?
Cevap
The range of an abiotic condition within which an organism can survive and reproduce.
Kart 800
Soru
What is evolutionary fitness?
Cevap
Relative contribution of an individual or genotype to future generations.
Kart 801
Soru
How can a thick cuticle and reduced leaves help a desert plant?
Cevap
The cuticle lowers surface permeability, while smaller leaves reduce the area from which water can evaporate.
Kart 802
Soru
Which term describes an adaptive behavior pattern?
Cevap
a behavioral adaptation
Kart 803
Soru
Which term describes the survivable range of an abiotic condition?
Cevap
an environmental tolerance range
Kart 804
Soru
Which term describes relative reproductive contribution to future generations?
Cevap
evolutionary fitness
Kart 805
Soru
How can a streamlined body adapt an aquatic animal to movement?
Cevap
It reduces drag, lowering the energy needed to move through water.
Kart 806
Soru
Does an organism develop an adaptation because it needs one?
Cevap
No. Heritable variants arise without regard to need, and selection changes their frequencies across generations.
Kart 807
Soru
Why may organisms from different thermal environments have enzymes with different temperature optima?
Cevap
Selection favors protein structures that balance flexibility and stability under local temperatures.
Kart 808
Soru
Why is an adaptation rarely beneficial in every environment?
Cevap
Traits carry costs and their advantage depends on local resources, competitors, predators, and physical conditions.
Kart 809
Soru
How does phenotypic plasticity differ from genetic adaptation?
Cevap
Plasticity lets one genotype produce different phenotypes; adaptation is a heritable population trait shaped across generations.
Kart 810
Soru
What is local adaptation?
Cevap
A population has higher fitness in its home environment than foreign populations because selection favored local traits.
Kart 811
Soru
What is an ecological niche?
Cevap
The set of environmental conditions, resources, interactions, and functional roles associated with a species.
Kart 812
Soru
What is a habitat?
Cevap
The physical place or environment where an organism lives.
Kart 813
Soru
What is a fundamental niche?
Cevap
The full range of conditions and resources a species could use without limiting biotic interactions.
Kart 814
Soru
What is a realized niche?
Cevap
The conditions and resources a species actually uses after competition and other interactions.
Kart 815
Soru
Which term describes a species' environmental requirements and ecological role?
Cevap
an ecological niche
Kart 816
Soru
Which term describes the place where an organism lives?
Cevap
a habitat
Kart 817
Soru
Which term describes the potential niche without limiting biotic interactions?
Cevap
a fundamental niche
Kart 818
Soru
Which term describes the niche actually occupied in nature?
Cevap
a realized niche
Kart 819
Soru
What is competition?
Cevap
An interaction in which organisms reduce one another's access to a limited resource.
Kart 820
Soru
What is mutualism?
Cevap
An interaction in which both participating species benefit.
Kart 821
Soru
What is predation?
Cevap
An interaction in which one organism kills and consumes another.
Kart 822
Soru
How does a habitat differ from a niche?
Cevap
A habitat is where an organism lives; a niche includes how it uses conditions and resources and interacts there.
Kart 823
Soru
Which term describes an interaction over a limited resource that harms both competitors?
Cevap
competition
Kart 824
Soru
Which term describes an interspecific interaction benefiting both partners?
Cevap
mutualism
Kart 825
Soru
Which term describes an interaction where one organism kills and eats another?
Cevap
predation
Kart 826
Soru
What kinds of factors define a niche?
Cevap
Abiotic factors such as temperature and moisture, plus biotic factors such as food, competitors, predators, and partners.
Kart 827
Soru
What does competitive exclusion predict?
Cevap
Species with effectively identical niches cannot coexist indefinitely under stable conditions; one is excluded or niches diverge.
Kart 828
Soru
How can resource partitioning reduce competition?
Cevap
Species use different resources, places, or times, reducing niche overlap.
Kart 829
Soru
What is a keystone species?
Cevap
A species whose effect on community structure is disproportionately large relative to its abundance.
Kart 830
Soru
Why can an introduced species expand rapidly in a new community?
Cevap
It may encounter abundant resources, suitable climate, and fewer predators, pathogens, or competitors.
Kart 831
Soru
Can an organism alter the niche conditions of other species?
Cevap
Yes. Ecosystem engineers modify habitat structure or resource availability, changing opportunities for other organisms.
Kart 832
Soru
What is a population?
Cevap
Individuals of the same species living in the same area at the same time.
Kart 833
Soru
What is an ecological community?
Cevap
Populations of different species living and interacting in an area.
Kart 834
Soru
What is an ecosystem?
Cevap
A community together with its physical environment and their interactions.
Kart 835
Soru
What is carrying capacity?
Cevap
The population size an environment can sustain over time under given conditions.
Kart 836
Soru
Which term describes same-species individuals sharing an area and time?
Cevap
a population
Kart 837
Soru
Which term describes interacting populations of different species?
Cevap
an ecological community
Kart 838
Soru
Which term describes a community plus its abiotic environment?
Cevap
an ecosystem
Kart 839
Soru
Which term describes the long-term supportable population size?
Cevap
carrying capacity
Kart 840
Soru
What is population density?
Cevap
The number of individuals per unit area or volume.
Kart 841
Soru
What is a limiting factor?
Cevap
A resource or condition that restricts population growth or distribution.
Kart 842
Soru
What is a density-dependent factor?
Cevap
A factor whose effect strengthens as population density increases.
Kart 843
Soru
What is a density-independent factor?
Cevap
A factor whose effect is not primarily determined by population density.
Kart 844
Soru
Which term describes individuals per unit area or volume?
Cevap
population density
Kart 845
Soru
Which term describes a resource or condition restricting a population?
Cevap
a limiting factor
Kart 846
Soru
Which term describes a factor with stronger effects at higher density?
Cevap
a density-dependent factor
Kart 847
Soru
Which term describes a factor acting largely regardless of population density?
Cevap
a density-independent factor
Kart 848
Soru
What is exponential population growth?
Cevap
Growth at a constant per-capita rate, producing a J-shaped curve under ideal conditions.
Kart 849
Soru
What is logistic population growth?
Cevap
Growth that slows as population size approaches carrying capacity, producing an S-shaped model.
Kart 850
Soru
What four processes directly change population size?
Cevap
Births and immigration increase it; deaths and emigration decrease it.
Kart 851
Soru
Under what conditions can exponential growth occur temporarily?
Cevap
Resources are abundant and limiting effects such as competition, disease, and predation are weak.
Kart 852
Soru
Which term describes J-shaped growth at constant per-capita rate?
Cevap
exponential population growth
Kart 853
Soru
Which term describes S-shaped growth that slows near carrying capacity?
Cevap
logistic population growth
Kart 854
Soru
Why is infectious disease often density dependent?
Cevap
Close or frequent contact at high density increases transmission opportunities.
Kart 855
Soru
Give an example of a density-independent population factor.
Cevap
A severe storm, wildfire, drought, or freeze can affect populations regardless of their initial density.
Kart 856
Soru
When is quadrat sampling useful?
Cevap
For estimating abundance or frequency of sessile or slow-moving organisms in defined areas.
Kart 857
Soru
What can a transect reveal?
Cevap
How species occurrence or abundance changes along an environmental gradient.
Kart 858
Soru
What can happen when a population overshoots carrying capacity?
Cevap
Resource depletion may raise mortality or lower reproduction, causing decline or oscillation.
Kart 859
Soru
What is the basic mark–recapture estimate of population size?
Cevap
First sample marked × second sample total ÷ marked individuals recaptured.
Kart 860
Soru
What assumptions improve a mark–recapture estimate?
Cevap
Marks persist and do not affect survival, marked individuals mix, capture probability is similar, and the population is effectively closed.
Kart 861
Soru
Why does a correlation between two population variables not prove causation?
Cevap
A third factor, reverse influence, chance, or biased sampling could produce the association.
Kart 862
Soru
What is a trophic level?
Cevap
A feeding position in a food chain or web.
Kart 863
Soru
What is a producer?
Cevap
An autotroph that converts inorganic carbon into organic matter.
Kart 864
Soru
What is a consumer?
Cevap
An organism obtaining energy and matter by eating other organisms or organic material.
Kart 865
Soru
What is a decomposer?
Cevap
An organism that externally digests dead material and wastes and absorbs the products.
Kart 866
Soru
Which term describes a feeding position in an ecosystem?
Cevap
a trophic level
Kart 867
Soru
Which term describes an autotroph forming organic matter?
Cevap
a producer
Kart 868
Soru
Which term describes an organism feeding on other organic matter?
Cevap
a consumer
Kart 869
Soru
Which term describes an organism digesting dead organic matter externally?
Cevap
a decomposer
Kart 870
Soru
What is a food chain?
Cevap
A linear representation of feeding and energy-transfer relationships.
Kart 871
Soru
What is a food web?
Cevap
A network of interconnected feeding relationships in a community.
Kart 872
Soru
What is gross primary productivity?
Cevap
The total rate at which producers capture energy into organic matter.
Kart 873
Soru
What is net primary productivity?
Cevap
Producer energy stored as new biomass after subtracting producer respiration from gross primary productivity.
Kart 874
Soru
Which term describes a linear feeding sequence?
Cevap
a food chain
Kart 875
Soru
Which term describes a network of connected food chains?
Cevap
a food web
Kart 876
Soru
Which term describes the total producer energy-capture rate?
Cevap
gross primary productivity
Kart 877
Soru
Which term describes producer biomass gain after respiration?
Cevap
net primary productivity
Kart 878
Soru
What is ecological productivity?
Cevap
The rate of biomass or energy production per unit area or volume.
Kart 879
Soru
What is a biogeochemical cycle?
Cevap
Movement of an element or compound through organisms and the physical environment.
Kart 880
Soru
Why is less energy available at each higher trophic level?
Cevap
Not all biomass is eaten or digested, and organisms use energy in respiration, movement, maintenance, and heat loss.
Kart 881
Soru
Why does energy flow rather than cycle through an ecosystem?
Cevap
Energy enters mainly as light and ultimately disperses as heat, which ecosystems cannot fully recycle.
Kart 882
Soru
Which term describes the rate of biomass or energy production?
Cevap
ecological productivity
Kart 883
Soru
Which term describes cycling of matter through living and nonliving reservoirs?
Cevap
a biogeochemical cycle
Kart 884
Soru
Why can matter cycle through an ecosystem?
Cevap
Atoms are conserved and repeatedly transferred among organisms, detritus, soil, water, and atmosphere.
Kart 885
Soru
Why is a pyramid of energy always upright?
Cevap
Usable energy decreases between trophic levels because every transfer includes losses.
Kart 886
Soru
How are gross and net primary productivity related?
Cevap
NPP = GPP − producer respiration.
Kart 887
Soru
How do decomposers support nutrient cycling?
Cevap
They break down dead material and wastes, releasing inorganic nutrients for reuse.
Kart 888
Soru
What processes move carbon rapidly between organisms and the atmosphere?
Cevap
Photosynthesis removes carbon dioxide; respiration, decomposition, and combustion release it.
Kart 889
Soru
Why is nitrogen fixation important?
Cevap
It converts atmospheric nitrogen gas into forms that can enter biological nitrogen metabolism.
Kart 890
Soru
How can excess nitrogen or phosphorus cause eutrophication?
Cevap
Nutrient enrichment drives algal growth; decomposition of the biomass consumes oxygen and can create hypoxic water.
Kart 891
Soru
Why can a persistent pollutant reach higher concentrations at higher trophic levels?
Cevap
Predators consume contaminant stored in many prey, and the substance is not readily broken down or excreted.
Kart 892
Soru
How is trophic-transfer efficiency calculated?
Cevap
Energy or biomass gained by the higher trophic level ÷ energy or biomass available at the lower level × 100%.
Kart 893
Soru
What is phenotypic variation?
Cevap
Differences in observable traits among individuals of a population.
Kart 894
Soru
What is heritable variation?
Cevap
Trait differences that can be transmitted genetically to offspring.
Kart 895
Soru
What is a selection pressure?
Cevap
An environmental factor causing differences in survival or reproduction among phenotypes.
Kart 896
Soru
What is relative fitness?
Cevap
An individual's reproductive success compared with others in the population.
Kart 897
Soru
Which term describes observable differences among individuals?
Cevap
phenotypic variation
Kart 898
Soru
Which term describes genetically transmissible trait differences?
Cevap
heritable variation
Kart 899
Soru
Which term describes an environmental factor producing differential reproductive success?
Cevap
a selection pressure
Kart 900
Soru
Which term describes reproductive success relative to other individuals?
Cevap
relative fitness
Kart 901
Soru
What is directional selection?
Cevap
Selection favoring one extreme phenotype and shifting a population's trait distribution.
Kart 902
Soru
What is stabilizing selection?
Cevap
Selection favoring intermediate phenotypes and acting against extremes.
Kart 903
Soru
What is disruptive selection?
Cevap
Selection favoring both extreme phenotypes over intermediates.
Kart 904
Soru
What is sexual selection?
Cevap
Selection arising from differences in mating success.
Kart 905
Soru
Which term describes selection shifting a trait toward one extreme?
Cevap
directional selection
Kart 906
Soru
Which term describes selection favoring intermediate phenotypes?
Cevap
stabilizing selection
Kart 907
Soru
Which term describes selection favoring both trait extremes?
Cevap
disruptive selection
Kart 908
Soru
Which term describes selection caused by unequal mating success?
Cevap
sexual selection
Kart 909
Soru
What conditions are required for natural selection?
Cevap
Individuals vary, some variation is heritable, more offspring are produced than can reproduce, and variants differ in reproductive success.
Kart 910
Soru
How does natural selection produce antibiotic-resistant bacterial populations?
Cevap
Existing resistant variants survive treatment and reproduce more than susceptible bacteria.
Kart 911
Soru
Does an antibiotic cause bacteria to mutate specifically toward resistance?
Cevap
No. Resistance variants arise without regard to need; treatment selects among them.
Kart 912
Soru
Can an individual become genetically adapted through natural selection?
Cevap
No. Selection acts on individuals, but adaptation is a population change across generations.
Kart 913
Soru
How does artificial selection differ from natural selection?
Cevap
Humans choose breeding traits in artificial selection; environmental conditions determine differential reproduction in natural selection.
Kart 914
Soru
How does natural selection change a population?
Cevap
Individuals with advantageous heritable variants leave more offspring, increasing those alleles over generations.
Kart 915
Soru
Why is fitness environment-dependent?
Cevap
A trait that improves reproduction in one environment may be neutral or costly in another.
Kart 916
Soru
How does genetic drift differ from natural selection?
Cevap
Drift changes allele frequencies by chance sampling; selection changes them through consistent fitness differences.
Kart 917
Soru
What is ecosystem stability?
Cevap
The capacity of an ecosystem to maintain or recover its structure and functions despite disturbance.
Kart 918
Soru
What is an ecological tipping point?
Cevap
A threshold beyond which feedbacks can drive a large and difficult-to-reverse ecosystem shift.
Kart 919
Soru
What is a mesocosm?
Cevap
A controlled, simplified ecosystem used to investigate ecological processes under more realistic conditions than a small laboratory vessel.
Kart 920
Soru
What is a sustainable yield?
Cevap
A harvest rate that can continue without causing long-term resource decline under prevailing conditions.
Kart 921
Soru
Which term describes the capacity of an ecosystem to persist or recover after disturbance?
Cevap
ecosystem stability
Kart 922
Soru
Which term describes a threshold triggering a major hard-to-reverse ecosystem shift?
Cevap
an ecological tipping point
Kart 923
Soru
Which term describes a controlled model ecosystem used for experiments?
Cevap
a mesocosm
Kart 924
Soru
Which term describes a harvest rate that avoids long-term depletion?
Cevap
a sustainable yield
Kart 925
Soru
What is eutrophication?
Cevap
Nutrient enrichment of water that stimulates excess primary production and can lead to oxygen depletion.
Kart 926
Soru
What is biomagnification?
Cevap
Increase in concentration of a persistent pollutant at successively higher trophic levels.
Kart 927
Soru
What is rewilding?
Cevap
Ecosystem restoration that rebuilds natural processes, species interactions, and self-sustaining ecological function.
Kart 928
Soru
What features can make an ecosystem more stable?
Cevap
Diverse functional roles, connected habitats, intact food webs, nutrient cycling, and balancing feedbacks can help the system resist or recover from disturbance.
Kart 929
Soru
Which term describes nutrient enrichment that can deplete oxygen in water?
Cevap
eutrophication
Kart 930
Soru
Which term describes increasing pollutant concentration up a food chain?
Cevap
biomagnification
Kart 931
Soru
Which term describes restoration focused on natural processes and self-sustaining ecosystems?
Cevap
rewilding
Kart 932
Soru
How could extensive Amazon deforestation push the ecosystem toward a tipping point?
Cevap
Loss of trees can reduce rainfall recycling and increase heat and fire, which cause further forest loss and may shift large areas toward a drier state.
Kart 933
Soru
What are a benefit and a limitation of using a mesocosm?
Cevap
It allows controlled experiments with interacting organisms, but its simplified scale cannot reproduce every process or long-term influence in a natural ecosystem.
Kart 934
Soru
Why should a fishery harvest below an uncertain maximum sustainable yield?
Cevap
Population estimates and recruitment vary, so a safety margin reduces the chance that error or a poor breeding year drives long-term decline.
Kart 935
Soru
How can intensive agriculture reduce ecosystem stability?
Cevap
Habitat loss, low crop diversity, soil degradation, heavy water use, pesticides, and nutrient runoff can weaken food webs and ecosystem processes.
Kart 936
Soru
Why can microplastic pollution harm aquatic ecosystems?
Cevap
Small persistent particles can be ingested, carry additives or other pollutants, damage feeding and tissues, and move through food webs.
Kart 937
Soru
How can rewilding improve ecosystem stability?
Cevap
Restoring native species, habitat connections, and natural disturbance or grazing processes can rebuild feedbacks and allow the ecosystem to maintain itself with less intervention.
Kart 938
Soru
What is the greenhouse effect?
Cevap
Warming caused when atmospheric gases absorb and re-emit outgoing infrared radiation.
Kart 939
Soru
What is a greenhouse gas?
Cevap
An atmospheric gas that absorbs infrared radiation at wavelengths emitted by Earth.
Kart 940
Soru
What is carbon dioxide (CO₂)?
Cevap
A long-lived greenhouse gas increased mainly by fossil-fuel combustion, cement production, and land-use change.
Kart 941
Soru
What is methane (CH₄)?
Cevap
A potent greenhouse gas emitted by sources including fossil-fuel systems, livestock, rice cultivation, wetlands, and waste.
Kart 942
Soru
Which term describes warming from absorption and re-emission of infrared radiation?
Cevap
the greenhouse effect
Kart 943
Soru
Which term describes an atmospheric infrared-absorbing gas?
Cevap
a greenhouse gas
Kart 944
Soru
Which term describes the long-lived greenhouse gas strongly increased by fossil fuels?
Cevap
carbon dioxide (CO₂)
Kart 945
Soru
Which term describes the potent short-lived greenhouse gas from biological and fossil sources?
Cevap
methane (CH₄)
Kart 946
Soru
What is albedo?
Cevap
The fraction of incoming radiation reflected by a surface.
Kart 947
Soru
What is a carbon sink?
Cevap
A reservoir that absorbs more carbon than it releases over a specified period.
Kart 948
Soru
What is ocean acidification?
Cevap
Decline in seawater pH caused mainly by absorption of human-emitted carbon dioxide.
Kart 949
Soru
What is climate change?
Cevap
A persistent change in the statistical patterns of climate over decades or longer.
Kart 950
Soru
Which term describes surface reflectivity?
Cevap
albedo
Kart 951
Soru
Which term describes a reservoir with net carbon uptake?
Cevap
a carbon sink
Kart 952
Soru
Which term describes seawater pH decline from absorbed carbon dioxide?
Cevap
ocean acidification
Kart 953
Soru
Which term describes long-term change in climate patterns?
Cevap
climate change
Kart 954
Soru
What is the enhanced greenhouse effect?
Cevap
Additional warming caused by human-driven increases in greenhouse-gas concentrations.
Kart 955
Soru
How do climate mitigation and climate adaptation differ?
Cevap
Mitigation limits the magnitude of climate change; adaptation reduces harm from changes that occur.
Kart 956
Soru
How does increasing greenhouse-gas concentration alter Earth's energy balance?
Cevap
Less outgoing infrared energy initially escapes to space, so the climate warms until energy balance is restored at a higher temperature.
Kart 957
Soru
How can melting ice amplify warming?
Cevap
Less bright ice lowers albedo, so darker land or water absorbs more solar energy and causes further warming.
Kart 958
Soru
How can climate change alter species distributions?
Cevap
Temperature, rainfall, seasons, sea level, and interactions shift, moving or shrinking areas with suitable conditions.
Kart 959
Soru
Why can ocean acidification harm calcifying organisms?
Cevap
Carbonate chemistry changes, reducing availability of carbonate ions used to build calcium-carbonate structures.
Kart 960
Soru
How can ecosystem protection contribute to climate mitigation?
Cevap
Protecting forests, wetlands, soils, and coastal habitats can avoid emissions and maintain or increase carbon storage.
960 kart
IB Biology SL Flashcards: Complete Course Review
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