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.
دربارهٔ این دسته
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.
کارتهای این دسته
کارت ۱
پرسش
What is water polarity?
پاسخ
The unequal sharing of electrons in a water molecule, giving oxygen a partial negative charge and the hydrogens partial positive charges.
کارت ۲
پرسش
What is a hydrogen bond?
پاسخ
A weak attraction between a partially positive hydrogen atom and a partially negative atom in another molecule.
کارت ۳
پرسش
What is cohesion?
پاسخ
Attraction between molecules of the same substance.
کارت ۴
پرسش
What is adhesion?
پاسخ
Attraction between molecules of different substances.
کارت ۵
پرسش
Which term describes unequal charge distribution within a water molecule?
پاسخ
water polarity
کارت ۶
پرسش
Which term describes the intermolecular attraction that links neighboring water molecules?
پاسخ
a hydrogen bond
کارت ۷
پرسش
Which term describes attraction between molecules of the same substance?
پاسخ
cohesion
کارت ۸
پرسش
Which term describes attraction between water and a different material?
پاسخ
adhesion
کارت ۹
پرسش
What is a solvent?
پاسخ
A liquid that dissolves solutes to form a solution.
کارت ۱۰
پرسش
What is specific heat capacity?
پاسخ
The energy required to raise the temperature of a unit mass of a substance by one degree.
کارت ۱۱
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What is latent heat of vaporization?
پاسخ
The energy required to vaporize a specified amount of liquid without changing its temperature.
کارت ۱۲
پرسش
Why does ice float on liquid water?
پاسخ
Hydrogen bonds hold water molecules in an open lattice in ice, making ice less dense than liquid water.
کارت ۱۳
پرسش
Which term describes a liquid that dissolves solutes?
پاسخ
a solvent
کارت ۱۴
پرسش
Which term describes the energy needed to raise a unit mass by one degree?
پاسخ
specific heat capacity
کارت ۱۵
پرسش
Which term describes the energy needed to vaporize a liquid without a temperature change?
پاسخ
latent heat of vaporization
کارت ۱۶
پرسش
Which property of water makes sweating an effective cooling mechanism?
پاسخ
Water absorbs substantial energy as it evaporates; the highest-energy molecules leave, carrying heat away from the skin.
کارت ۱۷
پرسش
Why does water resist rapid temperature change?
پاسخ
Many hydrogen bonds must absorb energy before molecular motion increases substantially, giving water a high specific heat capacity.
کارت ۱۸
پرسش
How do cohesion and adhesion support water transport in narrow tubes?
پاسخ
Cohesion keeps water molecules connected, while adhesion helps the water column cling to the tube wall.
کارت ۱۹
پرسش
How does water participate differently in hydrolysis and condensation?
پاسخ
Hydrolysis consumes water to split a bond; condensation forms a bond and releases water.
کارت ۲۰
پرسش
How does floating ice protect aquatic life in winter?
پاسخ
Surface ice insulates the liquid water below, slowing further heat loss and preventing the whole body of water from freezing rapidly.
کارت ۲۱
پرسش
Why is water effective for transporting many biological solutes?
پاسخ
Its polarity allows ions and other polar molecules to become surrounded and dispersed in solution.
کارت ۲۲
پرسش
Why do nonpolar substances tend to cluster in water?
پاسخ
Clustering reduces the nonpolar surface exposed to water, allowing more water molecules to maintain hydrogen-bond interactions.
کارت ۲۳
پرسش
What is a nucleotide?
پاسخ
A nucleic-acid monomer made of a pentose sugar, a phosphate group, and a nitrogenous base.
کارت ۲۴
پرسش
What is a nucleoside?
پاسخ
A nitrogenous base joined to a pentose sugar, without a phosphate group.
کارت ۲۵
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What is a phosphodiester bond?
پاسخ
A covalent bond linking the phosphate of one nucleotide to the sugar of the next nucleotide.
کارت ۲۶
پرسش
What is DNA?
پاسخ
A usually double-stranded nucleic acid that stores hereditary information in its base sequence.
کارت ۲۷
پرسش
Which term describes a sugar-phosphate-base monomer?
پاسخ
a nucleotide
کارت ۲۸
پرسش
Which term describes a base joined to a sugar but no phosphate?
پاسخ
a nucleoside
کارت ۲۹
پرسش
Which term describes the covalent linkage in a nucleic-acid sugar-phosphate backbone?
پاسخ
a phosphodiester bond
کارت ۳۰
پرسش
Which term describes the nucleic acid that usually stores hereditary information?
پاسخ
DNA
کارت ۳۱
پرسش
What is RNA?
پاسخ
A usually single-stranded nucleic acid involved in expressing and regulating genetic information.
کارت ۳۲
پرسش
What are antiparallel DNA strands?
پاسخ
Two DNA strands that run in opposite 5′ to 3′ directions.
کارت ۳۳
پرسش
What is complementary base pairing?
پاسخ
Specific pairing in which adenine pairs with thymine in DNA, or uracil in RNA, and cytosine pairs with guanine.
کارت ۳۴
پرسش
What is a purine?
پاسخ
A nitrogenous base with two fused rings; adenine and guanine are purines.
کارت ۳۵
پرسش
Which term describes the usually single-stranded nucleic acid used in gene expression?
پاسخ
RNA
کارت ۳۶
پرسش
Which term describes DNA strands running in opposite directions?
پاسخ
antiparallel DNA strands
کارت ۳۷
پرسش
Which term describes specific A–T or A–U and C–G pairing?
پاسخ
complementary base pairing
کارت ۳۸
پرسش
Which term describes a two-ring nitrogenous base?
پاسخ
a purine
کارت ۳۹
پرسش
What is a pyrimidine?
پاسخ
A nitrogenous base with one ring; cytosine, thymine, and uracil are pyrimidines.
کارت ۴۰
پرسش
What is a genome?
پاسخ
The complete genetic material of an organism or cell.
کارت ۴۱
پرسش
What three structural features commonly distinguish RNA from DNA?
پاسخ
RNA usually contains ribose, uses uracil instead of thymine, and is single-stranded rather than double-stranded.
کارت ۴۲
پرسش
What determines the base sequence of the second DNA strand?
پاسخ
Complementary base-pairing rules determine it: A pairs with T, and C pairs with G.
کارت ۴۳
پرسش
Which term describes a one-ring nitrogenous base?
پاسخ
a pyrimidine
کارت ۴۴
پرسش
Which term describes the complete genetic material of an organism?
پاسخ
a genome
کارت ۴۵
پرسش
What do the 5′ and 3′ labels of a nucleic-acid strand refer to?
پاسخ
They refer to numbered carbon atoms in the pentose sugar and define the strand's chemical direction.
کارت ۴۶
پرسش
Where is genetic information encoded in DNA?
پاسخ
In the order of nitrogenous bases along the DNA strand.
کارت ۴۷
پرسش
Why is ATP classified as a nucleotide?
پاسخ
It contains adenine, ribose, and phosphate groups, the three component types of a nucleotide.
کارت ۴۸
پرسش
How do mRNA, tRNA, and rRNA contribute to protein synthesis?
پاسخ
mRNA carries the coding sequence, tRNA delivers amino acids, and rRNA forms the catalytic and structural core of ribosomes.
کارت ۴۹
پرسش
How are a gene and a chromosome related?
پاسخ
A gene is a DNA sequence with a biological function; a chromosome is one long DNA molecule containing many genes and other sequences.
کارت ۵۰
پرسش
What happens to double-stranded DNA when it is denatured by heat?
پاسخ
Hydrogen bonds between complementary bases break and the two strands separate; the covalent backbones usually remain intact.
کارت ۵۱
پرسش
Why can each DNA strand serve as a template during replication?
پاسخ
Its base sequence determines a complementary sequence through specific base pairing.
کارت ۵۲
پرسش
In which direction are new nucleic-acid strands synthesized?
پاسخ
Nucleotides are added to the 3′ end, so synthesis proceeds 5′ to 3′.
کارت ۵۳
پرسش
What is a monosaccharide?
پاسخ
A single sugar unit that can serve as a carbohydrate monomer.
کارت ۵۴
پرسش
What is a disaccharide?
پاسخ
A carbohydrate formed from two monosaccharides joined by a glycosidic bond.
کارت ۵۵
پرسش
What is a polysaccharide?
پاسخ
A polymer made from many monosaccharide units.
کارت ۵۶
پرسش
What is a glycosidic bond?
پاسخ
A covalent bond joining monosaccharides in a carbohydrate.
کارت ۵۷
پرسش
Which term describes a single sugar unit?
پاسخ
a monosaccharide
کارت ۵۸
پرسش
Which term describes two monosaccharides joined together?
پاسخ
a disaccharide
کارت ۵۹
پرسش
Which term describes a polymer of many sugar units?
پاسخ
a polysaccharide
کارت ۶۰
پرسش
Which term describes the covalent linkage between monosaccharides?
پاسخ
a glycosidic bond
کارت ۶۱
پرسش
What is a triglyceride?
پاسخ
A lipid formed from glycerol joined to three fatty acids.
کارت ۶۲
پرسش
What is a fatty acid?
پاسخ
A hydrocarbon chain with a carboxyl group that can form part of many lipids.
کارت ۶۳
پرسش
What is a saturated fatty acid?
پاسخ
A fatty acid with no carbon-carbon double bonds in its hydrocarbon chain.
کارت ۶۴
پرسش
What is a phospholipid?
پاسخ
An amphipathic lipid with a phosphate-containing hydrophilic head and hydrophobic fatty-acid tails.
کارت ۶۵
پرسش
Which term describes glycerol joined to three fatty acids?
پاسخ
a triglyceride
کارت ۶۶
پرسش
Which term describes a hydrocarbon chain ending in a carboxyl group?
پاسخ
a fatty acid
کارت ۶۷
پرسش
Which term describes a fatty acid without carbon-carbon double bonds?
پاسخ
a saturated fatty acid
کارت ۶۸
پرسش
Which term describes a lipid with a polar head and nonpolar tails?
پاسخ
a phospholipid
کارت ۶۹
پرسش
How is a glycosidic bond formed between two monosaccharides?
پاسخ
A condensation reaction joins them and releases a molecule of water.
کارت ۷۰
پرسش
How is a polysaccharide broken into smaller sugars?
پاسخ
Hydrolysis adds water across glycosidic bonds, splitting the polymer.
کارت ۷۱
پرسش
Which polysaccharides store glucose in plants and animals?
پاسخ
Starch stores glucose in plants; glycogen stores glucose in animals and fungi.
کارت ۷۲
پرسش
Why is cellulose suitable for plant cell walls?
پاسخ
Its straight β-glucose chains hydrogen-bond into strong microfibrils that resist stretching.
کارت ۷۳
پرسش
Why do lipids store more energy per gram than carbohydrates?
پاسخ
Lipids contain more energy-rich carbon-hydrogen bonds and are more reduced.
کارت ۷۴
پرسش
Why do phospholipids form bilayers in water?
پاسخ
Hydrophilic heads interact with water while hydrophobic tails cluster away from water.
کارت ۷۵
پرسش
Besides energy storage, what are three biological roles of lipids?
پاسخ
They form membranes, provide thermal insulation and cushioning, and can act as signaling molecules.
کارت ۷۶
پرسش
How do cis double bonds affect fatty-acid packing and melting point?
پاسخ
They introduce bends that reduce close packing, usually lowering the melting point.
کارت ۷۷
پرسش
What is an amino acid?
پاسخ
A protein monomer with an amino group, a carboxyl group, a hydrogen, and a variable R group attached to a central carbon.
کارت ۷۸
پرسش
What is a peptide bond?
پاسخ
The covalent bond formed between the amino group of one amino acid and the carboxyl group of another.
کارت ۷۹
پرسش
What is a polypeptide?
پاسخ
A chain of amino acids joined by peptide bonds.
کارت ۸۰
پرسش
What is protein primary structure?
پاسخ
The amino-acid sequence of a polypeptide.
کارت ۸۱
پرسش
Which term describes a protein monomer with amino, carboxyl, and variable R groups?
پاسخ
an amino acid
کارت ۸۲
پرسش
Which term describes the covalent linkage between amino acids?
پاسخ
a peptide bond
کارت ۸۳
پرسش
Which term describes a chain of peptide-linked amino acids?
پاسخ
a polypeptide
کارت ۸۴
پرسش
Which term describes a protein's amino-acid sequence?
پاسخ
protein primary structure
کارت ۸۵
پرسش
What is protein secondary structure?
پاسخ
Local folding such as α-helices and β-sheets stabilized mainly by backbone hydrogen bonds.
کارت ۸۶
پرسش
What is protein tertiary structure?
پاسخ
The overall three-dimensional shape of one polypeptide produced by interactions among R groups and the backbone.
کارت ۸۷
پرسش
What is protein quaternary structure?
پاسخ
The arrangement of multiple polypeptide subunits in one functional protein.
کارت ۸۸
پرسش
What is protein denaturation?
پاسخ
Loss of a protein's normal three-dimensional shape and therefore usually its function.
کارت ۸۹
پرسش
Which term describes local α-helix and β-sheet folding?
پاسخ
protein secondary structure
کارت ۹۰
پرسش
Which term describes the overall three-dimensional shape of one polypeptide?
پاسخ
protein tertiary structure
کارت ۹۱
پرسش
Which term describes the association of multiple polypeptide subunits?
پاسخ
protein quaternary structure
کارت ۹۲
پرسش
Which term describes loss of a protein's native shape?
پاسخ
protein denaturation
کارت ۹۳
پرسش
What mainly gives different amino acids their different chemical properties?
پاسخ
Their variable R groups.
کارت ۹۴
پرسش
What reaction forms a peptide bond?
پاسخ
A condensation reaction releases water as the amino and carboxyl groups join.
کارت ۹۵
پرسش
Why can high temperature denature a protein?
پاسخ
Increased molecular motion disrupts weak interactions that maintain the protein's shape.
کارت ۹۶
پرسش
Why can extreme pH denature a protein?
پاسخ
It changes the charges of R groups and disrupts ionic and hydrogen-bond interactions.
کارت ۹۷
پرسش
How do fibrous and globular proteins generally differ?
پاسخ
Fibrous proteins are elongated and mainly structural; globular proteins are compact and often perform dynamic functions.
کارت ۹۸
پرسش
Why is three-dimensional shape crucial to protein function?
پاسخ
It creates specific binding, catalytic, structural, or interaction surfaces.
کارت ۹۹
پرسش
Name four broad biological roles of proteins.
پاسخ
Catalysis, transport, signaling, defense, movement, and structural support are major roles; any four are sufficient.
کارت ۱۰۰
پرسش
How can changing one amino acid alter protein function?
پاسخ
The substitution can change R-group interactions, folding, stability, or an active or binding site.
کارت ۱۰۱
پرسش
What is cell theory?
پاسخ
The principles that living organisms are made of cells, cells are the basic units of life, and cells arise from pre-existing cells.
کارت ۱۰۲
پرسش
What is a prokaryotic cell?
پاسخ
A cell without a nucleus or other membrane-bound organelles.
کارت ۱۰۳
پرسش
What is a eukaryotic cell?
پاسخ
A cell with DNA enclosed in a nucleus and with membrane-bound organelles.
کارت ۱۰۴
پرسش
What is the nucleus?
پاسخ
The double-membrane organelle that contains most of a eukaryotic cell's DNA.
کارت ۱۰۵
پرسش
Which term describes the principles describing cells as life's basic units?
پاسخ
cell theory
کارت ۱۰۶
پرسش
Which term describes a cell lacking a nucleus and membrane-bound organelles?
پاسخ
a prokaryotic cell
کارت ۱۰۷
پرسش
Which term describes a cell with a nucleus and membrane-bound organelles?
پاسخ
a eukaryotic cell
کارت ۱۰۸
پرسش
Which term describes the organelle containing most eukaryotic DNA?
پاسخ
the nucleus
کارت ۱۰۹
پرسش
What is a ribosome?
پاسخ
A molecular complex of rRNA and proteins that synthesizes polypeptides.
کارت ۱۱۰
پرسش
What is the cytoplasm?
پاسخ
The material inside the plasma membrane but outside the nucleus, including cytosol and organelles.
کارت ۱۱۱
پرسش
What is the plasma membrane?
پاسخ
The selectively permeable boundary separating a cell from its environment.
کارت ۱۱۲
پرسش
What is a cell wall?
پاسخ
A rigid extracellular layer that supports and protects cells in plants, fungi, and most prokaryotes.
کارت ۱۱۳
پرسش
Which term describes the complex that synthesizes polypeptides?
پاسخ
a ribosome
کارت ۱۱۴
پرسش
Which term describes cell contents inside the plasma membrane but outside the nucleus?
پاسخ
the cytoplasm
کارت ۱۱۵
پرسش
Which term describes the selectively permeable cell boundary?
پاسخ
the plasma membrane
کارت ۱۱۶
پرسش
Which term describes a rigid extracellular support layer?
پاسخ
a cell wall
کارت ۱۱۷
پرسش
What is the nucleoid?
پاسخ
The non-membrane-bound region containing the main chromosome of a prokaryotic cell.
کارت ۱۱۸
پرسش
What is the cytoskeleton?
پاسخ
A dynamic network of protein filaments involved in cell shape, transport, division, and movement.
کارت ۱۱۹
پرسش
What structures are shared by all cells?
پاسخ
A plasma membrane, cytoplasm, genetic material, and ribosomes.
کارت ۱۲۰
پرسش
Which structures distinguish a typical plant cell from a typical animal cell?
پاسخ
A plant cell has a cellulose wall, chloroplasts in photosynthetic tissues, and a large central vacuole; an animal cell lacks these.
کارت ۱۲۱
پرسش
Which term describes the prokaryotic chromosome-containing region?
پاسخ
the nucleoid
کارت ۱۲۲
پرسش
Which term describes the internal network of protein filaments?
پاسخ
the cytoskeleton
کارت ۱۲۳
پرسش
How is genetic material commonly organized in a prokaryotic cell?
پاسخ
The main DNA is usually one circular chromosome in the nucleoid, often accompanied by smaller plasmids.
کارت ۱۲۴
پرسش
How is microscope magnification calculated?
پاسخ
Magnification = image size ÷ actual size, using the same units.
کارت ۱۲۵
پرسش
What does microscope resolution describe?
پاسخ
The ability to distinguish two close points as separate.
کارت ۱۲۶
پرسش
Arrange these from smallest to largest: ribosome, bacterium, animal cell.
پاسخ
Ribosome, bacterium, animal cell.
کارت ۱۲۷
پرسش
How does the cytoskeleton support intracellular transport?
پاسخ
Motor proteins move vesicles and other cargo along cytoskeletal filaments.
کارت ۱۲۸
پرسش
Why does a small cell usually exchange materials more efficiently than a geometrically similar large cell?
پاسخ
It has a larger surface-area-to-volume ratio, providing more exchange surface per unit of cell contents.
کارت ۱۲۹
پرسش
Why is a cell more than a collection of isolated molecules?
پاسخ
Organized interactions among components produce emergent functions such as metabolism, regulation, and reproduction.
کارت ۱۳۰
پرسش
What major advantage do membrane-bound organelles give eukaryotic cells?
پاسخ
They separate incompatible reactions and create specialized local conditions.
کارت ۱۳۱
پرسش
What is a phospholipid bilayer?
پاسخ
A double layer of phospholipids with hydrophilic heads facing water and hydrophobic tails facing inward.
کارت ۱۳۲
پرسش
What is the fluid mosaic model?
پاسخ
A model describing membranes as mobile phospholipids containing a changing mosaic of proteins and other components.
کارت ۱۳۳
پرسش
What is an integral membrane protein?
پاسخ
A protein embedded in the bilayer, often spanning it.
کارت ۱۳۴
پرسش
What is a peripheral membrane protein?
پاسخ
A protein attached to a membrane surface rather than embedded in the bilayer.
کارت ۱۳۵
پرسش
Which term describes a double phospholipid layer with inward-facing tails?
پاسخ
a phospholipid bilayer
کارت ۱۳۶
پرسش
Which term describes the model of a mobile lipid layer containing varied proteins?
پاسخ
the fluid mosaic model
کارت ۱۳۷
پرسش
Which term describes a protein embedded within the lipid bilayer?
پاسخ
an integral membrane protein
کارت ۱۳۸
پرسش
Which term describes a protein attached to a membrane surface?
پاسخ
a peripheral membrane protein
کارت ۱۳۹
پرسش
What is membrane cholesterol?
پاسخ
An amphipathic lipid that buffers membrane fluidity and reduces permeability in animal cells.
کارت ۱۴۰
پرسش
What is a glycoprotein?
پاسخ
A protein with an attached carbohydrate chain, often used in recognition, adhesion, or signaling.
کارت ۱۴۱
پرسش
What is diffusion?
پاسخ
Net movement of particles from a region of higher concentration to lower concentration due to random motion.
کارت ۱۴۲
پرسش
What is osmosis?
پاسخ
Net movement of water across a selectively permeable membrane from higher water potential to lower water potential.
کارت ۱۴۳
پرسش
Which term describes the animal-membrane lipid that buffers fluidity?
پاسخ
membrane cholesterol
کارت ۱۴۴
پرسش
Which term describes a carbohydrate-bearing protein?
پاسخ
a glycoprotein
کارت ۱۴۵
پرسش
Which term describes net movement down a concentration gradient?
پاسخ
diffusion
کارت ۱۴۶
پرسش
Which term describes net water movement across a selectively permeable membrane?
پاسخ
osmosis
کارت ۱۴۷
پرسش
What is facilitated diffusion?
پاسخ
Passive movement down a gradient through a membrane channel or carrier protein.
کارت ۱۴۸
پرسش
What is active transport?
پاسخ
Energy-requiring movement of a substance against its concentration or electrochemical gradient.
کارت ۱۴۹
پرسش
Why is the phospholipid bilayer selectively permeable?
پاسخ
Its hydrophobic interior allows small nonpolar molecules through more readily than ions and most large or polar molecules.
کارت ۱۵۰
پرسش
How do simple diffusion and facilitated diffusion differ?
پاسخ
Both are passive, but facilitated diffusion uses specific membrane proteins while simple diffusion passes through the bilayer.
کارت ۱۵۱
پرسش
Which term describes passive transport through a channel or carrier?
پاسخ
facilitated diffusion
کارت ۱۵۲
پرسش
Which term describes energy-dependent transport against a gradient?
پاسخ
active transport
کارت ۱۵۳
پرسش
How do channel and carrier proteins differ?
پاسخ
Channels provide hydrophilic pores; carriers bind solutes and change shape to move them.
کارت ۱۵۴
پرسش
How can an ATP-driven pump maintain an ion gradient?
پاسخ
It couples ATP hydrolysis to a conformational change that moves ions against their electrochemical gradient.
کارت ۱۵۵
پرسش
How does endocytosis move material into a cell?
پاسخ
The plasma membrane folds inward and pinches off a vesicle containing the material.
کارت ۱۵۶
پرسش
How does exocytosis move material out of a cell?
پاسخ
An intracellular vesicle fuses with the plasma membrane and releases its contents outside.
کارت ۱۵۷
پرسش
What happens to an animal cell in a strongly hypotonic solution?
پاسخ
Water enters by osmosis; without a cell wall, the cell may swell and lyse.
کارت ۱۵۸
پرسش
Does molecular movement stop when diffusion reaches equilibrium?
پاسخ
No. Molecules continue moving randomly, but there is no net movement between regions.
کارت ۱۵۹
پرسش
How does decreasing temperature generally affect membrane fluidity?
پاسخ
It reduces phospholipid movement and makes the membrane less fluid.
کارت ۱۶۰
پرسش
Why do unsaturated fatty-acid tails increase membrane fluidity?
پاسخ
Their cis double-bond bends prevent phospholipids from packing tightly.
کارت ۱۶۱
پرسش
What changes increase the rate of simple diffusion across a membrane?
پاسخ
A steeper gradient, larger surface area, higher temperature, shorter distance, and greater membrane permeability increase the rate.
کارت ۱۶۲
پرسش
What is a mitochondrion?
پاسخ
A double-membrane organelle where most aerobic ATP production occurs.
کارت ۱۶۳
پرسش
What is a chloroplast?
پاسخ
A double-membrane organelle where photosynthesis occurs in plants and algae.
کارت ۱۶۴
پرسش
What is rough endoplasmic reticulum?
پاسخ
A membrane network bearing ribosomes that synthesizes and begins processing many secreted and membrane proteins.
کارت ۱۶۵
پرسش
What is smooth endoplasmic reticulum?
پاسخ
A membrane network involved in lipid synthesis, detoxification, and calcium storage.
کارت ۱۶۶
پرسش
Which term describes the main organelle of aerobic ATP production?
پاسخ
a mitochondrion
کارت ۱۶۷
پرسش
Which term describes the photosynthetic organelle of plants and algae?
پاسخ
a chloroplast
کارت ۱۶۸
پرسش
Which term describes the ribosome-studded membrane network?
پاسخ
rough endoplasmic reticulum
کارت ۱۶۹
پرسش
Which term describes the membrane network that lacks ribosomes and synthesizes lipids?
پاسخ
smooth endoplasmic reticulum
کارت ۱۷۰
پرسش
What is the Golgi apparatus?
پاسخ
Stacked membranes that modify, sort, and package proteins and lipids into vesicles.
کارت ۱۷۱
پرسش
What is a lysosome?
پاسخ
An acidic enzyme-containing organelle that digests macromolecules and worn cellular components.
کارت ۱۷۲
پرسش
What is a vesicle?
پاسخ
A small membrane-bound compartment used for transport, storage, or chemical reactions.
کارت ۱۷۳
پرسش
What is the central vacuole?
پاسخ
A large plant-cell compartment that stores solutes and helps maintain turgor pressure.
کارت ۱۷۴
پرسش
Which term describes the organelle that modifies and sorts cellular cargo?
پاسخ
the Golgi apparatus
کارت ۱۷۵
پرسش
Which term describes the acidic digestive organelle?
پاسخ
a lysosome
کارت ۱۷۶
پرسش
Which term describes a small membrane-bound transport compartment?
پاسخ
a vesicle
کارت ۱۷۷
پرسش
Which term describes the large plant compartment that supports turgor?
پاسخ
the central vacuole
کارت ۱۷۸
پرسش
Why can compartmentalization increase metabolic efficiency?
پاسخ
It concentrates enzymes and substrates, maintains suitable local conditions, and separates incompatible reactions.
کارت ۱۷۹
پرسش
How do mitochondrial cristae support ATP production?
پاسخ
They increase inner-membrane area for electron transport chains and ATP synthase.
کارت ۱۸۰
پرسش
Why are chloroplast thylakoids arranged as extensive membranes?
پاسخ
They provide a large surface for light-absorbing complexes, electron transport chains, and ATP synthase.
کارت ۱۸۱
پرسش
What is the main function of the nucleolus?
پاسخ
It produces rRNA and assembles ribosomal subunits.
کارت ۱۸۲
پرسش
Trace a secreted protein from synthesis to release.
پاسخ
Ribosome on rough ER → ER lumen → transport vesicle → Golgi apparatus → secretory vesicle → plasma membrane → exocytosis.
کارت ۱۸۳
پرسش
Why does a lysosome maintain an acidic interior?
پاسخ
Its hydrolytic enzymes work best at low pH, and acidity helps confine their activity from the cytosol.
کارت ۱۸۴
پرسش
How do the nucleus, ribosomes, ER, and Golgi cooperate in protein production?
پاسخ
DNA instructions are transcribed in the nucleus; ribosomes translate them; ER folds or modifies many products; Golgi further modifies and sorts them.
کارت ۱۸۵
پرسش
How are transport vesicles directed to the correct target membrane?
پاسخ
Specific recognition proteins on vesicles and target membranes interact, allowing selective docking and fusion.
کارت ۱۸۶
پرسش
What is cell differentiation?
پاسخ
The process by which a cell develops specialized structure and function.
کارت ۱۸۷
پرسش
What is a stem cell?
پاسخ
An unspecialized cell able to self-renew and produce differentiated cells.
کارت ۱۸۸
پرسش
What is gene expression?
پاسخ
Use of genetic information to produce a functional RNA or protein product.
کارت ۱۸۹
پرسش
What is a tissue?
پاسخ
A coordinated group of similar or related cells performing a shared function.
کارت ۱۹۰
پرسش
Which term describes development of specialized cell structure and function?
پاسخ
cell differentiation
کارت ۱۹۱
پرسش
Which term describes an unspecialized self-renewing cell?
پاسخ
a stem cell
کارت ۱۹۲
پرسش
Which term describes production of a functional product from genetic information?
پاسخ
gene expression
کارت ۱۹۳
پرسش
Which term describes a group of coordinated cells with a shared function?
پاسخ
a tissue
کارت ۱۹۴
پرسش
What is an organ?
پاسخ
A structure made of multiple tissues working together for particular functions.
کارت ۱۹۵
پرسش
What is the organ-system level of biological organization?
پاسخ
A group of organs that coordinate to perform major functions for an organism.
کارت ۱۹۶
پرسش
What is surface-area-to-volume ratio?
پاسخ
The amount of surface area available relative to the volume it must serve.
کارت ۱۹۷
پرسش
How can two specialized cells have the same genome but different structures?
پاسخ
They express different sets and amounts of genes, producing different proteins and cellular features.
کارت ۱۹۸
پرسش
Which term describes a structure composed of multiple tissue types?
پاسخ
an organ
کارت ۱۹۹
پرسش
Which term describes the level of biological organization formed by coordinated organs?
پاسخ
an organ system
کارت ۲۰۰
پرسش
Which term describes surface area available per unit volume?
پاسخ
surface-area-to-volume ratio
کارت ۲۰۱
پرسش
How is a mammalian red blood cell specialized for oxygen transport?
پاسخ
Its biconcave shape increases exchange area, it is flexible, and loss of its nucleus leaves more space for hemoglobin.
کارت ۲۰۲
پرسش
How is a sperm cell specialized for fertilization?
پاسخ
It has a flagellum for movement, many mitochondria for ATP, a haploid nucleus, and an acrosome containing enzymes.
کارت ۲۰۳
پرسش
How is a neuron specialized for rapid communication?
پاسخ
Long processes carry signals over distance, branching dendrites receive inputs, and synaptic terminals transmit signals to other cells.
کارت ۲۰۴
پرسش
How is a root hair cell specialized for mineral and water uptake?
پاسخ
Its long projection increases surface area, its thin wall shortens the pathway, and membrane transport proteins take up ions.
کارت ۲۰۵
پرسش
How is a palisade mesophyll cell specialized for photosynthesis?
پاسخ
It contains many chloroplasts and is positioned near the upper leaf surface where light is strongest.
کارت ۲۰۶
پرسش
How do ciliated epithelial cells help protect airways?
پاسخ
Their cilia move mucus containing trapped particles and microbes toward the throat.
کارت ۲۰۷
پرسش
Why can extreme specialization reduce a cell's independence?
پاسخ
Resources and structures are committed to a narrow role, so the cell depends on other cells for functions it no longer performs well.
کارت ۲۰۸
پرسش
What is water potential?
پاسخ
The potential energy of water per unit volume relative to pure water, used to predict the direction of water movement.
کارت ۲۰۹
پرسش
What is solute potential?
پاسخ
The negative contribution of dissolved solutes to water potential.
کارت ۲۱۰
پرسش
What is pressure potential?
پاسخ
The contribution of physical pressure to water potential.
کارت ۲۱۱
پرسش
What is turgor pressure?
پاسخ
Outward pressure of a plant-cell interior against its cell wall after water uptake.
کارت ۲۱۲
پرسش
Which term describes the tendency of water to move relative to pure water?
پاسخ
water potential
کارت ۲۱۳
پرسش
Which term describes the water-potential component lowered by dissolved solutes?
پاسخ
solute potential
کارت ۲۱۴
پرسش
Which term describes the water-potential component caused by physical pressure?
پاسخ
pressure potential
کارت ۲۱۵
پرسش
Which term describes pressure of plant-cell contents against the wall?
پاسخ
turgor pressure
کارت ۲۱۶
پرسش
What is plasmolysis?
پاسخ
Separation of the plasma membrane from the cell wall after a plant cell loses water.
کارت ۲۱۷
پرسش
What is a flaccid plant cell?
پاسخ
A plant cell with insufficient turgor pressure to be firm.
کارت ۲۱۸
پرسش
What is an isotonic condition?
پاسخ
A condition in which two solutions have equal effective water potential and no net water movement occurs.
کارت ۲۱۹
پرسش
In which direction does water move across a permeable membrane?
پاسخ
From higher water potential to lower water potential.
کارت ۲۲۰
پرسش
Which term describes membrane separation from the plant cell wall after water loss?
پاسخ
plasmolysis
کارت ۲۲۱
پرسش
Which term describes a plant cell lacking firm turgor?
پاسخ
a flaccid plant cell
کارت ۲۲۲
پرسش
Which term describes equal effective water potential across a membrane?
پاسخ
an isotonic condition
کارت ۲۲۳
پرسش
What is the water potential of pure water at standard pressure?
پاسخ
Zero; adding solute makes water potential more negative.
کارت ۲۲۴
پرسش
How are water potential, solute potential, and pressure potential related?
پاسخ
Water potential equals solute potential plus pressure potential: Ψ = Ψs + Ψp.
کارت ۲۲۵
پرسش
Why does a plant cell usually become turgid rather than burst in a hypotonic solution?
پاسخ
Water entry raises pressure potential, while the rigid cell wall resists further expansion.
کارت ۲۲۶
پرسش
What happens to a plant cell placed in a solution with much lower water potential?
پاسخ
Water leaves the cell, turgor falls, and severe loss can cause plasmolysis.
کارت ۲۲۷
پرسش
Can two solutions have different solute concentrations but equal water potential?
پاسخ
Yes. A difference in pressure potential can offset a difference in solute potential.
کارت ۲۲۸
پرسش
What is an enzyme?
پاسخ
A biological catalyst that increases reaction rate without being consumed.
کارت ۲۲۹
پرسش
What is an active site?
پاسخ
The region of an enzyme where substrate binds and catalysis occurs.
کارت ۲۳۰
پرسش
What is a substrate?
پاسخ
A reactant molecule on which an enzyme acts.
کارت ۲۳۱
پرسش
What is activation energy?
پاسخ
The minimum energy input needed for a reaction to begin.
کارت ۲۳۲
پرسش
Which term describes a biological catalyst?
پاسخ
an enzyme
کارت ۲۳۳
پرسش
Which term describes the substrate-binding catalytic region of an enzyme?
پاسخ
an active site
کارت ۲۳۴
پرسش
Which term describes a reactant bound and changed by an enzyme?
پاسخ
a substrate
کارت ۲۳۵
پرسش
Which term describes the energy barrier that must be overcome for a reaction?
پاسخ
activation energy
کارت ۲۳۶
پرسش
What is the induced-fit model?
پاسخ
The model in which substrate binding changes active-site shape to improve catalytic interactions.
کارت ۲۳۷
پرسش
What is enzyme denaturation?
پاسخ
Loss of the active three-dimensional shape of an enzyme, usually causing loss of activity.
کارت ۲۳۸
پرسش
What is competitive inhibition?
پاسخ
Inhibition caused by a molecule competing with substrate for the active site.
کارت ۲۳۹
پرسش
What is noncompetitive inhibition?
پاسخ
Inhibition caused by binding away from the active site and reducing catalytic function.
کارت ۲۴۰
پرسش
Which term describes the model where substrate binding reshapes the active site?
پاسخ
the induced-fit model
کارت ۲۴۱
پرسش
Which term describes loss of an enzyme's functional shape?
پاسخ
enzyme denaturation
کارت ۲۴۲
پرسش
Which term describes inhibition by active-site competition?
پاسخ
competitive inhibition
کارت ۲۴۳
پرسش
Which term describes inhibition by binding outside the active site?
پاسخ
noncompetitive inhibition
کارت ۲۴۴
پرسش
What is an enzyme optimum?
پاسخ
The condition, such as temperature or pH, at which an enzyme's activity is highest.
کارت ۲۴۵
پرسش
What is feedback inhibition?
پاسخ
Control in which a pathway product inhibits an enzyme acting earlier in the pathway.
کارت ۲۴۶
پرسش
How does an enzyme increase reaction rate?
پاسخ
It stabilizes the transition state and provides a pathway with lower activation energy.
کارت ۲۴۷
پرسش
Why does enzyme activity often rise and then fall as temperature increases?
پاسخ
Molecular collisions initially increase, but excessive heat disrupts enzyme shape and denatures the active site.
کارت ۲۴۸
پرسش
Which term describes the condition producing maximum enzyme activity?
پاسخ
an enzyme optimum
کارت ۲۴۹
پرسش
Which term describes pathway control by inhibition from an end product?
پاسخ
feedback inhibition
کارت ۲۵۰
پرسش
Why does each enzyme have a characteristic pH range?
پاسخ
pH changes the ionization of amino-acid side chains, affecting active-site shape and chemical interactions.
کارت ۲۵۱
پرسش
Why does increasing substrate concentration eventually stop increasing enzyme rate?
پاسخ
At saturation, nearly all active sites are occupied and enzyme concentration limits the maximum rate.
کارت ۲۵۲
پرسش
How does increasing enzyme concentration affect rate when substrate is abundant?
پاسخ
More active sites are available, so the initial rate increases roughly in proportion to enzyme concentration.
کارت ۲۵۳
پرسش
What gives an enzyme substrate specificity?
پاسخ
The active site's shape, charge, polarity, and chemical groups complement particular substrates and transition states.
کارت ۲۵۴
پرسش
What is one practical advantage of immobilizing an enzyme?
پاسخ
The enzyme can be separated from products and reused while conditions around it are controlled.
کارت ۲۵۵
پرسش
Does an enzyme change a reaction's equilibrium position?
پاسخ
No. It speeds forward and reverse reactions but does not change the equilibrium constant or final equilibrium position.
کارت ۲۵۶
پرسش
How can high substrate concentration reduce competitive inhibition?
پاسخ
More substrate molecules increase the chance that substrate rather than inhibitor occupies the active site.
کارت ۲۵۷
پرسش
Why are metabolic reactions commonly organized into pathways?
پاسخ
A sequence of enzyme-controlled steps allows energy changes and intermediates to be controlled and coupled.
کارت ۲۵۸
پرسش
What is ATP?
پاسخ
A nucleotide that transfers usable energy through coupling of its hydrolysis to cellular processes.
کارت ۲۵۹
پرسش
What is cellular respiration?
پاسخ
Controlled release of energy from organic molecules to produce ATP.
کارت ۲۶۰
پرسش
What is glycolysis?
پاسخ
A cytosolic pathway that splits glucose into two pyruvate molecules and yields a small amount of ATP and reduced electron carriers.
کارت ۲۶۱
پرسش
What is pyruvate?
پاسخ
The three-carbon product of glycolysis that can enter aerobic or anaerobic pathways.
کارت ۲۶۲
پرسش
Which term describes the cell's immediate phosphoryl-group energy carrier?
پاسخ
ATP
کارت ۲۶۳
پرسش
Which term describes controlled ATP-producing breakdown of organic molecules?
پاسخ
cellular respiration
کارت ۲۶۴
پرسش
Which term describes the cytosolic splitting of glucose into pyruvate?
پاسخ
glycolysis
کارت ۲۶۵
پرسش
Which term describes the three-carbon product of glycolysis?
پاسخ
pyruvate
کارت ۲۶۶
پرسش
What is aerobic respiration?
پاسخ
Respiration that uses oxygen as the final electron acceptor and produces much more ATP than fermentation.
کارت ۲۶۷
پرسش
What is anaerobic metabolism?
پاسخ
ATP-producing metabolism that proceeds without oxygen.
کارت ۲۶۸
پرسش
What is fermentation?
پاسخ
An anaerobic pathway that regenerates oxidized electron carriers so glycolysis can continue.
کارت ۲۶۹
پرسش
What is oxidation?
پاسخ
Loss of electrons, often accompanied in biology by loss of hydrogen or gain of oxygen.
کارت ۲۷۰
پرسش
Which term describes respiration using oxygen as final electron acceptor?
پاسخ
aerobic respiration
کارت ۲۷۱
پرسش
Which term describes ATP-producing metabolism without oxygen?
پاسخ
anaerobic metabolism
کارت ۲۷۲
پرسش
Which term describes anaerobic regeneration of electron carriers after glycolysis?
پاسخ
fermentation
کارت ۲۷۳
پرسش
Which term describes loss of electrons?
پاسخ
oxidation
کارت ۲۷۴
پرسش
What is reduction?
پاسخ
Gain of electrons, often accompanied in biology by gain of hydrogen or loss of oxygen.
کارت ۲۷۵
پرسش
What is a reduced electron carrier?
پاسخ
A molecule such as NADH that carries high-energy electrons and hydrogen from one reaction to another.
کارت ۲۷۶
پرسش
What is chemiosmosis?
پاسخ
ATP production driven by ions moving down an electrochemical gradient through ATP synthase.
کارت ۲۷۷
پرسش
What is the overall word equation for aerobic respiration of glucose?
پاسخ
Glucose + oxygen → carbon dioxide + water + energy transferred to ATP and heat.
کارت ۲۷۸
پرسش
Which term describes gain of electrons?
پاسخ
reduction
کارت ۲۷۹
پرسش
Which term describes a molecule carrying high-energy electrons between reactions?
پاسخ
a reduced electron carrier
کارت ۲۸۰
پرسش
Which term describes ATP production powered by an ion gradient?
پاسخ
chemiosmosis
کارت ۲۸۱
پرسش
Where does glycolysis occur?
پاسخ
In the cytosol.
کارت ۲۸۲
پرسش
What major stages of aerobic respiration occur in mitochondria?
پاسخ
Pyruvate oxidation and the citric acid cycle occur in the matrix; electron transport and chemiosmosis occur at the inner membrane.
کارت ۲۸۳
پرسش
What is oxygen's direct role in aerobic respiration?
پاسخ
It accepts electrons and hydrogen ions at the end of the electron transport chain, forming water.
کارت ۲۸۴
پرسش
Why does aerobic respiration yield much more ATP per glucose than fermentation?
پاسخ
It transfers electrons through an electron transport chain and uses oxidative phosphorylation, extracting far more of glucose's energy.
کارت ۲۸۵
پرسش
What is the purpose of lactate formation in oxygen-limited animal cells?
پاسخ
It regenerates NAD⁺ so glycolysis can continue producing a small amount of ATP.
کارت ۲۸۶
پرسش
What products are formed during alcoholic fermentation in yeast?
پاسخ
Ethanol and carbon dioxide, while NAD⁺ is regenerated.
کارت ۲۸۷
پرسش
Why is some energy released by respiration transferred as heat rather than captured in ATP?
پاسخ
Energy conversions are not fully efficient, so part of the chemical energy becomes disordered molecular motion.
کارت ۲۸۸
پرسش
What is substrate-level phosphorylation?
پاسخ
Direct transfer of a phosphate group from a metabolic intermediate to ADP to form ATP.
کارت ۲۸۹
پرسش
How does electron transport lead to ATP synthesis in mitochondria?
پاسخ
Electron energy pumps protons across the inner membrane; proton flow back through ATP synthase drives ATP formation.
کارت ۲۹۰
پرسش
Why can intense exercise increase lactate production?
پاسخ
ATP demand can exceed oxygen delivery and aerobic capacity, so cells regenerate NAD⁺ through lactate formation to sustain glycolysis.
کارت ۲۹۱
پرسش
What is photosynthesis?
پاسخ
Conversion of light energy into chemical energy used to synthesize organic molecules from carbon dioxide.
کارت ۲۹۲
پرسش
What is chlorophyll?
پاسخ
A green pigment that absorbs light energy for photosynthesis.
کارت ۲۹۳
پرسش
What is an absorption spectrum?
پاسخ
A graph showing how strongly a pigment absorbs different wavelengths of light.
کارت ۲۹۴
پرسش
What is an action spectrum?
پاسخ
A graph showing the rate or effectiveness of photosynthesis at different wavelengths.
کارت ۲۹۵
پرسش
Which term describes light-driven synthesis of organic molecules from carbon dioxide?
پاسخ
photosynthesis
کارت ۲۹۶
پرسش
Which term describes the principal green photosynthetic pigment?
پاسخ
chlorophyll
کارت ۲۹۷
پرسش
Which term describes a graph of pigment absorption versus wavelength?
پاسخ
an absorption spectrum
کارت ۲۹۸
پرسش
Which term describes a graph of photosynthetic effectiveness versus wavelength?
پاسخ
an action spectrum
کارت ۲۹۹
پرسش
What is photolysis of water?
پاسخ
Light-driven splitting of water that supplies electrons and hydrogen ions and releases oxygen.
کارت ۳۰۰
پرسش
What are light-dependent reactions?
پاسخ
Photosynthetic reactions that use light to generate ATP and reduced electron carriers while releasing oxygen.
کارت ۳۰۱
پرسش
What is the Calvin cycle?
پاسخ
A set of chloroplast reactions that uses ATP and reduced electron carriers to convert carbon dioxide into carbohydrate precursors.
کارت ۳۰۲
پرسش
What is carbon fixation?
پاسخ
Incorporation of inorganic carbon dioxide into an organic molecule.
کارت ۳۰۳
پرسش
Which term describes light-driven splitting of water?
پاسخ
photolysis of water
کارت ۳۰۴
پرسش
Which term describes photosynthetic reactions that directly capture light energy?
پاسخ
light-dependent reactions
کارت ۳۰۵
پرسش
Which term describes the carbon-reduction cycle of photosynthesis?
پاسخ
the Calvin cycle
کارت ۳۰۶
پرسش
Which term describes incorporation of carbon dioxide into organic matter?
پاسخ
carbon fixation
کارت ۳۰۷
پرسش
What is the role of a stoma in photosynthesis?
پاسخ
A pore in the leaf epidermis that regulates carbon-dioxide entry as well as water loss.
کارت ۳۰۸
پرسش
What is a limiting factor of photosynthesis?
پاسخ
The environmental factor whose availability currently restricts the photosynthetic rate.
کارت ۳۰۹
پرسش
What is the light compensation point?
پاسخ
The light intensity at which photosynthetic carbon uptake equals respiratory carbon release.
کارت ۳۱۰
پرسش
What is the overall word equation for oxygenic photosynthesis?
پاسخ
Carbon dioxide + water → carbohydrate + oxygen, using light energy.
کارت ۳۱۱
پرسش
Which term describes the regulated leaf pore controlling carbon-dioxide entry for photosynthesis?
پاسخ
a stoma
کارت ۳۱۲
پرسش
Which term describes the factor currently restricting photosynthetic rate?
پاسخ
a limiting factor
کارت ۳۱۳
پرسش
Which term describes the light level where photosynthesis and respiration balance?
پاسخ
the light compensation point
کارت ۳۱۴
پرسش
Where do the main stages of photosynthesis occur in a chloroplast?
پاسخ
Light-dependent reactions occur in thylakoid membranes; carbon-fixation reactions occur in the stroma.
کارت ۳۱۵
پرسش
What energy conversion occurs during photosynthesis?
پاسخ
Light energy is converted into chemical energy stored first in ATP and reduced carriers and ultimately in organic molecules.
کارت ۳۱۶
پرسش
From which reactant does the oxygen released by photosynthesis originate?
پاسخ
Water.
کارت ۳۱۷
پرسش
What role does RuBisCO play in photosynthesis?
پاسخ
It catalyzes fixation of carbon dioxide by adding it to an organic acceptor molecule.
کارت ۳۱۸
پرسش
What tradeoff is controlled when stomata open?
پاسخ
Opening permits carbon dioxide entry but increases water loss by transpiration.
کارت ۳۱۹
پرسش
Name three leaf features that support photosynthesis.
پاسخ
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.
کارت ۳۲۰
پرسش
What can a plant do with carbohydrate made by photosynthesis?
پاسخ
Use it in respiration, convert it to storage or structural carbohydrates, or use its carbon to make lipids, amino acids, and other molecules.
کارت ۳۲۱
پرسش
How are products of the light-dependent reactions used in carbon fixation?
پاسخ
ATP supplies energy and NADPH supplies reducing power for conversion of fixed carbon into carbohydrate precursors.
کارت ۳۲۲
پرسش
Why does increasing light intensity eventually stop increasing photosynthetic rate?
پاسخ
Another factor, such as carbon dioxide supply, temperature, or biochemical capacity, becomes limiting.
کارت ۳۲۳
پرسش
How can increasing carbon dioxide concentration affect photosynthetic rate?
پاسخ
It can increase the rate until another factor becomes limiting.
کارت ۳۲۴
پرسش
Why does photosynthetic rate usually have a temperature optimum?
پاسخ
Enzyme-controlled reactions accelerate with temperature up to an optimum, then decline as enzymes and membranes lose effective function.
کارت ۳۲۵
پرسش
Why does an action spectrum broadly resemble the combined absorption spectra of photosynthetic pigments?
پاسخ
Wavelengths absorbed by the pigments supply more energy for photosynthesis than poorly absorbed wavelengths.
کارت ۳۲۶
پرسش
What is semiconservative replication?
پاسخ
DNA replication in which each daughter molecule contains one parental strand and one newly synthesized strand.
کارت ۳۲۷
پرسش
What is DNA helicase?
پاسخ
An enzyme that unwinds the double helix and separates the strands by disrupting base pairing.
کارت ۳۲۸
پرسش
What is DNA polymerase?
پاسخ
An enzyme that adds nucleotides to a growing DNA strand using a template.
کارت ۳۲۹
پرسش
What is a primer?
پاسخ
A short nucleic-acid segment providing a free 3′ end from which DNA polymerase can extend.
کارت ۳۳۰
پرسش
Which term describes replication producing one old and one new strand per DNA molecule?
پاسخ
semiconservative replication
کارت ۳۳۱
پرسش
Which term describes the enzyme that separates DNA strands?
پاسخ
DNA helicase
کارت ۳۳۲
پرسش
Which term describes the enzyme that builds DNA from a template?
پاسخ
DNA polymerase
کارت ۳۳۳
پرسش
Which term describes the short segment providing a starting 3′ end?
پاسخ
a primer
کارت ۳۳۴
پرسش
What is the leading strand?
پاسخ
The new DNA strand synthesized continuously toward the replication fork.
کارت ۳۳۵
پرسش
What is the lagging strand?
پاسخ
The new DNA strand synthesized discontinuously away from the replication fork.
کارت ۳۳۶
پرسش
What is an Okazaki fragment?
پاسخ
A short DNA segment synthesized on the lagging strand.
کارت ۳۳۷
پرسش
What is DNA ligase?
پاسخ
An enzyme that seals breaks in the sugar-phosphate backbone, joining DNA fragments.
کارت ۳۳۸
پرسش
Which term describes the continuously synthesized daughter strand?
پاسخ
the leading strand
کارت ۳۳۹
پرسش
Which term describes the discontinuously synthesized daughter strand?
پاسخ
the lagging strand
کارت ۳۴۰
پرسش
Which term describes a short newly made segment of lagging-strand DNA?
پاسخ
an Okazaki fragment
کارت ۳۴۱
پرسش
Which term describes the enzyme that joins DNA fragments by sealing the backbone?
پاسخ
DNA ligase
کارت ۳۴۲
پرسش
How does complementary base pairing ensure accurate DNA copying?
پاسخ
Each template base specifies the nucleotide added opposite it: A pairs with T, and C pairs with G.
کارت ۳۴۳
پرسش
Why does DNA polymerase synthesize DNA only 5′ to 3′?
پاسخ
It can add a nucleotide only to the free 3′ hydroxyl group of the growing strand.
کارت ۳۴۴
پرسش
When in the cell cycle is nuclear DNA replicated?
پاسخ
During S phase of interphase, before cell division.
کارت ۳۴۵
پرسش
How can a replication error become a permanent mutation?
پاسخ
If it escapes proofreading and repair, the altered sequence can be copied in later cell generations.
کارت ۳۴۶
پرسش
Why are leading and lagging strands synthesized differently?
پاسخ
The templates are antiparallel while DNA polymerase works only 5′ to 3′, forcing one strand to be made discontinuously.
کارت ۳۴۷
پرسش
How do proofreading and repair reduce replication errors?
پاسخ
Incorrectly paired nucleotides are recognized, removed, and replaced before or after replication continues.
کارت ۳۴۸
پرسش
What three repeating steps amplify DNA in PCR?
پاسخ
Strand separation by heating, primer annealing during cooling, and DNA extension by a heat-stable polymerase.
کارت ۳۴۹
پرسش
What determines which DNA region PCR amplifies?
پاسخ
The sequences and positions of the two primers flanking the target region.
کارت ۳۵۰
پرسش
What is transcription?
پاسخ
Synthesis of RNA from a DNA template.
کارت ۳۵۱
پرسش
What is RNA polymerase?
پاسخ
The enzyme that synthesizes RNA complementary to a DNA template strand.
کارت ۳۵۲
پرسش
What is messenger RNA?
پاسخ
RNA carrying a coding sequence from DNA to ribosomes.
کارت ۳۵۳
پرسش
What is a codon?
پاسخ
A three-base sequence in mRNA that specifies an amino acid or a translation signal.
کارت ۳۵۴
پرسش
Which term describes RNA synthesis from DNA?
پاسخ
transcription
کارت ۳۵۵
پرسش
Which term describes the enzyme that builds RNA from a DNA template?
پاسخ
RNA polymerase
کارت ۳۵۶
پرسش
Which term describes RNA that carries coding information to ribosomes?
پاسخ
messenger RNA
کارت ۳۵۷
پرسش
Which term describes a three-base mRNA unit?
پاسخ
a codon
کارت ۳۵۸
پرسش
What is translation?
پاسخ
Synthesis of a polypeptide using the codon sequence of mRNA.
کارت ۳۵۹
پرسش
What does a ribosome do during translation?
پاسخ
It reads mRNA and catalyzes polypeptide synthesis using its rRNA-protein machinery.
کارت ۳۶۰
پرسش
What is transfer RNA?
پاسخ
RNA that carries a specific amino acid and pairs its anticodon with an mRNA codon.
کارت ۳۶۱
پرسش
What is an anticodon?
پاسخ
A three-base tRNA sequence complementary to an mRNA codon.
کارت ۳۶۲
پرسش
Which term describes polypeptide synthesis from an mRNA sequence?
پاسخ
translation
کارت ۳۶۳
پرسش
Which term describes the translation complex that reads mRNA and builds a polypeptide?
پاسخ
a ribosome
کارت ۳۶۴
پرسش
Which term describes the adaptor RNA carrying an amino acid?
پاسخ
transfer RNA
کارت ۳۶۵
پرسش
Which term describes the tRNA triplet that pairs with a codon?
پاسخ
an anticodon
کارت ۳۶۶
پرسش
What is the genetic code?
پاسخ
The set of rules relating mRNA codons to amino acids and translation signals.
کارت ۳۶۷
پرسش
What are start and stop codons?
پاسخ
mRNA signals that establish the reading frame or terminate translation.
کارت ۳۶۸
پرسش
Where do transcription and translation occur in a eukaryotic cell?
پاسخ
Transcription occurs in the nucleus; translation occurs on ribosomes in the cytoplasm or on rough ER.
کارت ۳۶۹
پرسش
How is an mRNA sequence related to its DNA template strand?
پاسخ
It is complementary and antiparallel, with uracil in RNA opposite adenine in DNA.
کارت ۳۷۰
پرسش
Which term describes the codon-to-amino-acid rule set?
پاسخ
the genetic code
کارت ۳۷۱
پرسش
Which term describes codons that begin or end translation?
پاسخ
start and stop codons
کارت ۳۷۲
پرسش
What reaction does the ribosome catalyze as a polypeptide grows?
پاسخ
Formation of peptide bonds between adjacent amino acids.
کارت ۳۷۳
پرسش
What does it mean that the genetic code is degenerate?
پاسخ
Most amino acids are specified by more than one codon.
کارت ۳۷۴
پرسش
How can one mRNA produce many polypeptides quickly?
پاسخ
Multiple ribosomes can translate the same mRNA simultaneously as a polyribosome.
کارت ۳۷۵
پرسش
Why is translation not the final step in producing many functional proteins?
پاسخ
The polypeptide must fold and may undergo cleavage, chemical modification, or assembly with other subunits.
کارت ۳۷۶
پرسش
How does mRNA compare with the DNA coding strand?
پاسخ
It has the same base sequence except that RNA contains uracil where DNA contains thymine.
کارت ۳۷۷
پرسش
What happens during eukaryotic RNA splicing?
پاسخ
Introns are removed and exons are joined to form mature mRNA.
کارت ۳۷۸
پرسش
Why must codons be read in the correct reading frame?
پاسخ
Changing the starting position changes every downstream triplet and therefore the amino-acid sequence.
کارت ۳۷۹
پرسش
How is the correct amino acid matched to each mRNA codon?
پاسخ
Each tRNA is charged with a particular amino acid, and its anticodon pairs with the complementary codon.
کارت ۳۸۰
پرسش
How can a base substitution affect a protein?
پاسخ
It may be silent, change one amino acid, create a stop codon, or sometimes alter RNA processing.
کارت ۳۸۱
پرسش
What is a mutation?
پاسخ
A change in a DNA sequence or chromosome structure that can be passed to daughter cells.
کارت ۳۸۲
پرسش
What is a base substitution?
پاسخ
Replacement of one nucleotide pair by another.
کارت ۳۸۳
پرسش
What is an insertion mutation?
پاسخ
Addition of one or more nucleotides to a DNA sequence.
کارت ۳۸۴
پرسش
What is a deletion mutation?
پاسخ
Loss of one or more nucleotides from a DNA sequence.
کارت ۳۸۵
پرسش
Which term describes a lasting DNA-sequence or chromosome change?
پاسخ
a mutation
کارت ۳۸۶
پرسش
Which term describes replacement of one DNA base pair?
پاسخ
a base substitution
کارت ۳۸۷
پرسش
Which term describes addition of nucleotides to DNA?
پاسخ
an insertion mutation
کارت ۳۸۸
پرسش
Which term describes loss of nucleotides from DNA?
پاسخ
a deletion mutation
کارت ۳۸۹
پرسش
What is a frameshift mutation?
پاسخ
A coding-sequence insertion or deletion not divisible by three that changes downstream codon grouping.
کارت ۳۹۰
پرسش
What is a silent mutation?
پاسخ
A sequence change that does not alter the encoded amino acid.
کارت ۳۹۱
پرسش
What is a missense mutation?
پاسخ
A mutation that changes a codon so a different amino acid is incorporated.
کارت ۳۹۲
پرسش
What is a nonsense mutation?
پاسخ
A mutation that changes an amino-acid codon into a stop codon.
کارت ۳۹۳
پرسش
Which term describes a mutation that shifts downstream codon grouping?
پاسخ
a frameshift mutation
کارت ۳۹۴
پرسش
Which term describes a coding change that leaves the amino acid unchanged?
پاسخ
a silent mutation
کارت ۳۹۵
پرسش
Which term describes a mutation causing one amino-acid substitution?
پاسخ
a missense mutation
کارت ۳۹۶
پرسش
Which term describes a mutation creating a premature stop codon?
پاسخ
a nonsense mutation
کارت ۳۹۷
پرسش
How do germline and somatic mutations differ in inheritance?
پاسخ
Germline mutations can enter gametes and be inherited; somatic mutations affect a cell lineage within the individual.
کارت ۳۹۸
پرسش
What can cause mutations?
پاسخ
Replication errors, spontaneous chemical changes, radiation, and mutagenic chemicals can alter DNA.
کارت ۳۹۹
پرسش
How does DNA repair protect genome stability?
پاسخ
Repair systems detect damaged or mismatched DNA and restore the correct structure or sequence when possible.
کارت ۴۰۰
پرسش
Why are mutations essential to evolution despite often being neutral or harmful?
پاسخ
They create new alleles, providing the heritable variation on which selection and drift act.
کارت ۴۰۱
پرسش
What is the basic role of guide RNA in CRISPR gene editing?
پاسخ
It directs a nuclease to a complementary DNA sequence.
کارت ۴۰۲
پرسش
Why can the same type of DNA mutation have effects ranging from none to severe?
پاسخ
Effects depend on location, genetic-code redundancy, protein role, cell type, and environmental context.
کارت ۴۰۳
پرسش
How can accumulated mutations contribute to cancer?
پاسخ
Mutations can activate growth-promoting genes or disable genes that restrain division, repair DNA, or trigger cell death.
کارت ۴۰۴
پرسش
Why can repairing a CRISPR-induced DNA break produce different editing outcomes?
پاسخ
Different cellular repair pathways may disrupt the target sequence or use a supplied template for a specific change.
کارت ۴۰۵
پرسش
What is an off-target effect in gene editing?
پاسخ
An unintended DNA change at a site sufficiently similar to the intended target.
کارت ۴۰۶
پرسش
Why does heritable human genome editing raise additional ethical concerns?
پاسخ
Changes could pass to future generations who cannot consent, with uncertain long-term biological and social effects.
کارت ۴۰۷
پرسش
What is the cell cycle?
پاسخ
The ordered sequence of cell growth, DNA replication, nuclear division, and cell division.
کارت ۴۰۸
پرسش
What is interphase?
پاسخ
The period of growth, normal activity, and DNA replication between nuclear divisions.
کارت ۴۰۹
پرسش
What is mitosis?
پاسخ
Nuclear division that usually produces genetically equivalent daughter nuclei.
کارت ۴۱۰
پرسش
What is cytokinesis?
پاسخ
Division of the cytoplasm to form separate daughter cells.
کارت ۴۱۱
پرسش
Which term describes the ordered sequence from one cell division to the next?
پاسخ
the cell cycle
کارت ۴۱۲
پرسش
Which term describes the growth and DNA-replication period between divisions?
پاسخ
interphase
کارت ۴۱۳
پرسش
Which term describes division producing genetically equivalent nuclei?
پاسخ
mitosis
کارت ۴۱۴
پرسش
Which term describes physical division of the cytoplasm?
پاسخ
cytokinesis
کارت ۴۱۵
پرسش
What is a chromosome?
پاسخ
One DNA molecule packaged with associated proteins.
کارت ۴۱۶
پرسش
What are sister chromatids?
پاسخ
The two replicated copies of a chromosome joined before separation.
کارت ۴۱۷
پرسش
What is a centromere?
پاسخ
The chromosome region that holds sister chromatids together and organizes kinetochore attachment.
کارت ۴۱۸
پرسش
What is the mitotic spindle?
پاسخ
A microtubule system that attaches to and separates chromosomes during cell division.
کارت ۴۱۹
پرسش
Which term describes a protein-packaged DNA molecule?
پاسخ
a chromosome
کارت ۴۲۰
پرسش
Which term describes joined replicated copies of one chromosome?
پاسخ
sister chromatids
کارت ۴۲۱
پرسش
Which term describes the chromosome region joining sister chromatids?
پاسخ
a centromere
کارت ۴۲۲
پرسش
Which term describes the chromosome-separating microtubule system?
پاسخ
the mitotic spindle
کارت ۴۲۳
پرسش
What is the basic sequence of mitosis?
پاسخ
Chromosomes condense, align at the cell equator, sister chromatids separate to opposite poles, and new nuclei form.
کارت ۴۲۴
پرسش
Why must DNA replicate before mitosis?
پاسخ
Each chromosome must have two copies so each daughter nucleus can receive a complete genome.
کارت ۴۲۵
پرسش
Why are daughter cells from mitosis usually genetically similar?
پاسخ
Replicated sister chromatids are separated so each daughter receives one copy of every chromosome.
کارت ۴۲۶
پرسش
What are major roles of mitosis in multicellular organisms?
پاسخ
Growth, tissue repair, cell replacement, and some forms of asexual reproduction.
کارت ۴۲۷
پرسش
How do homologous chromosomes differ from sister chromatids?
پاسخ
Homologs carry the same gene loci but may have different alleles; sister chromatids are replicated copies of one chromosome.
کارت ۴۲۸
پرسش
What key outcome distinguishes mitosis from meiosis?
پاسخ
Mitosis usually preserves chromosome number and similarity; meiosis halves chromosome number and generates genetically varied haploid cells.
کارت ۴۲۹
پرسش
How does cytokinesis commonly occur in animal cells?
پاسخ
A contractile ring tightens the plasma membrane into a cleavage furrow.
کارت ۴۳۰
پرسش
How does cytokinesis commonly occur in plant cells?
پاسخ
Vesicles fuse at the center to form a cell plate that develops into new membranes and a cell wall.
کارت ۴۳۱
پرسش
What is the purpose of cell-cycle checkpoints?
پاسخ
They delay progression when conditions are unsuitable or DNA and chromosome attachment are defective.
کارت ۴۳۲
پرسش
How is loss of cell-cycle control related to cancer?
پاسخ
Cells can divide despite damage or growth restraints, producing an expanding abnormal clone.
کارت ۴۳۳
پرسش
What is a gene?
پاسخ
A DNA sequence that contributes to a functional product and influences a characteristic or cellular process.
کارت ۴۳۴
پرسش
What is an allele?
پاسخ
One of the alternative DNA-sequence forms at a gene locus.
کارت ۴۳۵
پرسش
What is a gene locus?
پاسخ
The physical position of a gene on a chromosome.
کارت ۴۳۶
پرسش
What is a genotype?
پاسخ
The allele combination of an organism at one or more loci.
کارت ۴۳۷
پرسش
Which term describes a functional DNA sequence?
پاسخ
a gene
کارت ۴۳۸
پرسش
Which term describes an alternative form of a gene?
پاسخ
an allele
کارت ۴۳۹
پرسش
Which term describes a gene's chromosome position?
پاسخ
a gene locus
کارت ۴۴۰
پرسش
Which term describes an organism's allele combination?
پاسخ
a genotype
کارت ۴۴۱
پرسش
What is a phenotype?
پاسخ
An observable or measurable trait produced by genotype and environment.
کارت ۴۴۲
پرسش
What is homozygous?
پاسخ
Having two identical alleles at a diploid locus.
کارت ۴۴۳
پرسش
What is heterozygous?
پاسخ
Having two different alleles at a diploid locus.
کارت ۴۴۴
پرسش
What is a dominant allele?
پاسخ
An allele expressed in the phenotype of a heterozygote under a specified inheritance model.
کارت ۴۴۵
پرسش
Which term describes an observable trait resulting from genes and environment?
پاسخ
a phenotype
کارت ۴۴۶
پرسش
Which term describes having two identical alleles at a locus?
پاسخ
homozygous
کارت ۴۴۷
پرسش
Which term describes having two different alleles at a locus?
پاسخ
heterozygous
کارت ۴۴۸
پرسش
Which term describes an allele expressed in a heterozygote?
پاسخ
a dominant allele
کارت ۴۴۹
پرسش
What is a recessive allele?
پاسخ
An allele whose phenotype is masked by a dominant allele in a heterozygote.
کارت ۴۵۰
پرسش
What is a genetic carrier?
پاسخ
An unaffected heterozygote who can transmit a recessive disease allele.
کارت ۴۵۱
پرسش
What is a test cross?
پاسخ
A cross with a homozygous recessive individual used to infer an unknown dominant phenotype's genotype.
کارت ۴۵۲
پرسش
What is a pedigree?
پاسخ
A diagram showing biological relationships and occurrence of a trait across generations.
کارت ۴۵۳
پرسش
Which term describes an allele masked in a heterozygote?
پاسخ
a recessive allele
کارت ۴۵۴
پرسش
Which term describes an unaffected heterozygote carrying a recessive disease allele?
پاسخ
a genetic carrier
کارت ۴۵۵
پرسش
Which term describes a cross used to reveal an unknown dominant genotype?
پاسخ
a test cross
کارت ۴۵۶
پرسش
Which term describes a family diagram tracking a trait across generations?
پاسخ
a pedigree
کارت ۴۵۷
پرسش
What does allele segregation mean during gamete formation?
پاسخ
The two alleles at a diploid locus separate so each gamete receives one.
کارت ۴۵۸
پرسش
What does a Punnett square predict?
پاسخ
Expected genotype and phenotype probabilities from specified parental gametes, not guaranteed family outcomes.
کارت ۴۵۹
پرسش
What phenotypic ratio is expected from Aa × Aa with complete dominance?
پاسخ
Approximately 3 dominant phenotype : 1 recessive phenotype.
کارت ۴۶۰
پرسش
What genotypic ratio is expected from Aa × Aa?
پاسخ
1 AA : 2 Aa : 1 aa.
کارت ۴۶۱
پرسش
What happens in codominance?
پاسخ
Both alleles contribute distinctly to the heterozygous phenotype.
کارت ۴۶۲
پرسش
What happens in incomplete dominance?
پاسخ
The heterozygote has a phenotype intermediate between the two homozygotes.
کارت ۴۶۳
پرسش
How can environment affect phenotype without changing genotype?
پاسخ
Conditions alter development, physiology, or gene expression, changing the observed trait.
کارت ۴۶۴
پرسش
What is the ultimate source of new alleles?
پاسخ
Mutation.
کارت ۴۶۵
پرسش
Why are X-linked recessive traits more common in XY individuals?
پاسخ
They have only one X chromosome, so one recessive allele on it can determine the phenotype.
کارت ۴۶۶
پرسش
When is the product rule used in genetic probability?
پاسخ
For independent events that must both occur; multiply their probabilities.
کارت ۴۶۷
پرسش
When is the sum rule used in genetic probability?
پاسخ
For mutually exclusive alternative outcomes; add their probabilities.
کارت ۴۶۸
پرسش
Why do polygenic traits often show continuous variation?
پاسخ
Many loci contribute small effects, creating many possible genotypes and phenotypes, often further influenced by environment.
کارت ۴۶۹
پرسش
What pedigree pattern can suggest an autosomal recessive trait?
پاسخ
Unaffected parents can have affected children, and all sexes are affected at similar frequencies.
کارت ۴۷۰
پرسش
What is a species?
پاسخ
A group of organisms whose members can potentially interbreed and produce fertile offspring under natural conditions.
کارت ۴۷۱
پرسش
What is binomial nomenclature?
پاسخ
The two-part scientific naming system using a genus name followed by a specific epithet.
کارت ۴۷۲
پرسش
What is taxonomy?
پاسخ
The naming and classification of organisms.
کارت ۴۷۳
پرسش
What is a biological domain?
پاسخ
The broadest commonly used taxonomic rank, separating Bacteria, Archaea, and Eukarya.
کارت ۴۷۴
پرسش
Which term describes a naturally interbreeding group producing fertile offspring?
پاسخ
a species
کارت ۴۷۵
پرسش
Which term describes the genus-plus-specific-epithet naming system?
پاسخ
binomial nomenclature
کارت ۴۷۶
پرسش
Which term describes the science of naming and classifying organisms?
پاسخ
taxonomy
کارت ۴۷۷
پرسش
Which term describes the broadest common taxonomic rank?
پاسخ
a biological domain
کارت ۴۷۸
پرسش
What is biodiversity?
پاسخ
Variation of life at genetic, species, and ecosystem levels.
کارت ۴۷۹
پرسش
What is an autotroph?
پاسخ
An organism that makes organic compounds from inorganic carbon using light or chemical energy.
کارت ۴۸۰
پرسش
What is a heterotroph?
پاسخ
An organism that obtains organic carbon by consuming other organisms or their products.
۹۶۰ کارت
IB Biology SL Flashcards: Complete Course Review
این دسته را رایگان مطالعه کنیدNibomo باز میشود تا بتوانید مطالعه را شروع کنید.
کارت ۴۸۱
پرسش
What is a unicellular organism?
پاسخ
An organism consisting of one cell that carries out all essential life functions.
کارت ۴۸۲
پرسش
Which term describes variation of life across genes, species, and ecosystems?
پاسخ
biodiversity
کارت ۴۸۳
پرسش
Which term describes an organism that builds organic matter from inorganic carbon?
پاسخ
an autotroph
کارت ۴۸۴
پرسش
Which term describes an organism obtaining organic carbon from other organisms?
پاسخ
a heterotroph
کارت ۴۸۵
پرسش
Which term describes an organism made of one cell?
پاسخ
a unicellular organism
کارت ۴۸۶
پرسش
What is a multicellular organism?
پاسخ
An organism composed of many cooperating cells, often with specialized cell types.
کارت ۴۸۷
پرسش
What is a karyotype?
پاسخ
An ordered display of chromosomes used to examine their number and large-scale structure.
کارت ۴۸۸
پرسش
What broad feature distinguishes both Bacteria and Archaea from Eukarya?
پاسخ
Their cells lack a nucleus and other membrane-bound organelles.
کارت ۴۸۹
پرسش
What features characterize most plant cells?
پاسخ
Cellulose walls, chloroplasts in photosynthetic tissues, and large vacuoles are typical features.
کارت ۴۹۰
پرسش
Which term describes an organism made of many cooperating cells?
پاسخ
a multicellular organism
کارت ۴۹۱
پرسش
Which term describes an ordered display of an individual's chromosomes?
پاسخ
a karyotype
کارت ۴۹۲
پرسش
How do fungi obtain nutrients?
پاسخ
They secrete digestive enzymes and absorb soluble products; their cells usually have chitin-containing walls.
کارت ۴۹۳
پرسش
What distinguishes animal nutrition and cell structure?
پاسخ
Animals ingest organic material, and their cells lack cell walls and chloroplasts.
کارت ۴۹۴
پرسش
Why are scientific names useful across languages?
پاسخ
A standardized name identifies the same organism internationally and reduces ambiguity from local common names.
کارت ۴۹۵
پرسش
Why can genetic diversity improve a population's resilience?
پاسخ
More heritable variation increases the chance that some individuals tolerate new diseases or environmental changes.
کارت ۴۹۶
پرسش
What does ecosystem diversity measure?
پاسخ
The variety of habitats, communities, and ecological processes within a region.
کارت ۴۹۷
پرسش
Why are Archaea classified separately from Bacteria?
پاسخ
They differ in genetic sequences, membrane chemistry, cell-wall composition, and aspects of molecular machinery.
کارت ۴۹۸
پرسش
Why is the biological species concept difficult to apply to fossils or asexual organisms?
پاسخ
Their ability to interbreed and produce fertile offspring cannot be tested in the usual way.
کارت ۴۹۹
پرسش
Does a larger chromosome number necessarily mean a more complex organism?
پاسخ
No. Chromosome number varies through fusion, fission, and duplication and does not directly measure biological complexity.
کارت ۵۰۰
پرسش
Does genome size reliably predict organismal complexity?
پاسخ
No. Large amounts of noncoding and repeated DNA make genome size a poor simple measure of complexity.
کارت ۵۰۱
پرسش
What evidence can be combined when classifying organisms?
پاسخ
Molecular sequences, cell structure, anatomy, development, physiology, and reproductive evidence can all contribute.
کارت ۵۰۲
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What is gas exchange?
پاسخ
Diffusion of respiratory gases between an organism and its environment or transport fluid.
کارت ۵۰۳
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What is ventilation?
پاسخ
Bulk movement of air or water over a gas-exchange surface.
کارت ۵۰۴
پرسش
What is an alveolus?
پاسخ
A microscopic air sac in the lung where gases diffuse between air and blood.
کارت ۵۰۵
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What is pulmonary surfactant?
پاسخ
A substance lining alveoli that lowers surface tension and reduces collapse.
کارت ۵۰۶
پرسش
Which term describes diffusion of oxygen and carbon dioxide across a respiratory surface?
پاسخ
gas exchange
کارت ۵۰۷
پرسش
Which term describes bulk movement of respiratory medium over an exchange surface?
پاسخ
ventilation
کارت ۵۰۸
پرسش
Which term describes a microscopic lung air sac?
پاسخ
an alveolus
کارت ۵۰۹
پرسش
Which term describes the alveolar lining that lowers surface tension?
پاسخ
pulmonary surfactant
کارت ۵۱۰
پرسش
What is the diaphragm?
پاسخ
A sheet of skeletal muscle whose contraction increases thoracic volume during inhalation.
کارت ۵۱۱
پرسش
What is tidal volume?
پاسخ
The volume of air moved in or out during a normal breath.
کارت ۵۱۲
پرسش
What is a stoma?
پاسخ
A regulated epidermal pore through which gases diffuse in leaves.
کارت ۵۱۳
پرسش
What is countercurrent exchange?
پاسخ
Exchange between fluids moving in opposite directions, maintaining a gradient along most of the surface.
کارت ۵۱۴
پرسش
Which term describes the muscle sheet that expands the thorax during inhalation?
پاسخ
the diaphragm
کارت ۵۱۵
پرسش
Which term describes air volume moved in one normal breath?
پاسخ
tidal volume
کارت ۵۱۶
پرسش
Which term describes a regulated leaf gas-exchange pore?
پاسخ
a stoma
کارت ۵۱۷
پرسش
Which term describes opposite fluid flow that maintains an exchange gradient?
پاسخ
countercurrent exchange
کارت ۵۱۸
پرسش
What features make an efficient gas-exchange surface?
پاسخ
Large area, short diffusion distance, permeability, and maintained concentration gradients.
کارت ۵۱۹
پرسش
How is a steep oxygen gradient maintained across alveoli?
پاسخ
Ventilation replenishes alveolar oxygen and blood flow removes absorbed oxygen.
کارت ۵۲۰
پرسش
How does diaphragm contraction cause inhalation?
پاسخ
Thoracic volume increases, lung pressure falls below atmospheric pressure, and air flows inward.
کارت ۵۲۱
پرسش
What drives quiet exhalation?
پاسخ
The diaphragm relaxes and elastic recoil reduces thoracic and lung volume, raising pressure and pushing air out.
کارت ۵۲۲
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Why do ventilation rate and depth increase during exercise?
پاسخ
They increase oxygen uptake and carbon dioxide removal to support higher cellular respiration.
کارت ۵۲۳
پرسش
How does leaf structure shorten the pathway for carbon dioxide diffusion?
پاسخ
Stomata open into air spaces, and mesophyll cells expose moist surfaces close to those spaces.
کارت ۵۲۴
پرسش
Why does carbon dioxide diffuse from tissues into blood?
پاسخ
Respiring cells produce carbon dioxide, making its partial pressure higher in tissues than in incoming blood.
کارت ۵۲۵
پرسش
How does countercurrent flow improve oxygen uptake at fish gills?
پاسخ
Blood continually meets water with a higher oxygen concentration, preserving diffusion along the lamella.
کارت ۵۲۶
پرسش
Why does closing stomata reduce both water loss and photosynthesis?
پاسخ
It limits water-vapor diffusion out but also restricts carbon dioxide diffusion into the leaf.
کارت ۵۲۷
پرسش
What is a circulatory system?
پاسخ
A transport system that moves a fluid carrying gases, nutrients, wastes, hormones, and heat through an organism.
کارت ۵۲۸
پرسش
What is an artery?
پاسخ
A blood vessel carrying blood away from the heart under relatively high pressure.
کارت ۵۲۹
پرسش
What is a vein?
پاسخ
A blood vessel carrying blood toward the heart, usually with low pressure and often valves.
کارت ۵۳۰
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What is a capillary?
پاسخ
A microscopic thin-walled vessel where substances exchange between blood and tissues.
کارت ۵۳۱
پرسش
Which term describes an internal fluid-transport system?
پاسخ
a circulatory system
کارت ۵۳۲
پرسش
Which term describes a vessel carrying blood away from the heart?
پاسخ
an artery
کارت ۵۳۳
پرسش
Which term describes a vessel carrying blood toward the heart?
پاسخ
a vein
کارت ۵۳۴
پرسش
Which term describes a microscopic exchange blood vessel?
پاسخ
a capillary
کارت ۵۳۵
پرسش
What is the cardiac cycle?
پاسخ
The repeating sequence of heart-chamber contraction and relaxation that pumps blood.
کارت ۵۳۶
پرسش
What is hemoglobin?
پاسخ
An iron-containing protein in red blood cells that binds oxygen reversibly.
کارت ۵۳۷
پرسش
What is xylem?
پاسخ
Plant vascular tissue that transports water and mineral ions and provides structural support.
کارت ۵۳۸
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What is phloem?
پاسخ
Plant vascular tissue that transports sucrose and other organic solutes between sources and sinks.
کارت ۵۳۹
پرسش
Which term describes the repeating pumping sequence of the heart?
پاسخ
the cardiac cycle
کارت ۵۴۰
پرسش
Which term describes the oxygen-carrying protein of red blood cells?
پاسخ
hemoglobin
کارت ۵۴۱
پرسش
Which term describes plant tissue carrying water and minerals?
پاسخ
xylem
کارت ۵۴۲
پرسش
Which term describes plant tissue carrying organic solutes?
پاسخ
phloem
کارت ۵۴۳
پرسش
What is transpiration?
پاسخ
Loss of water vapor from plant surfaces, mainly through stomata.
کارت ۵۴۴
پرسش
What is phloem translocation?
پاسخ
Movement of organic solutes through phloem from sources to sinks.
کارت ۵۴۵
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How do a source and a sink differ in plant transport?
پاسخ
A source releases assimilates to phloem; a sink removes them for use or storage.
کارت ۵۴۶
پرسش
What makes human circulation a double circulation?
پاسخ
Blood passes through the heart once in the pulmonary circuit and again in the systemic circuit during one complete journey.
کارت ۵۴۷
پرسش
Which term describes water-vapor loss from plant surfaces?
پاسخ
transpiration
کارت ۵۴۸
پرسش
Which term describes movement of organic solutes through phloem?
پاسخ
phloem translocation
کارت ۵۴۹
پرسش
Which term describes the exporting and importing regions of phloem transport?
پاسخ
source and sink
کارت ۵۵۰
پرسش
How is an artery adapted to high pressure?
پاسخ
It has thick elastic and muscular walls and a relatively narrow lumen.
کارت ۵۵۱
پرسش
How is a vein adapted to return low-pressure blood?
پاسخ
It has a wide lumen, thinner walls, and valves that reduce backflow.
کارت ۵۵۲
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How does capillary structure support exchange?
پاسخ
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.
کارت ۵۵۳
پرسش
What determines whether a heart valve opens or closes?
پاسخ
Pressure differences across the valve.
کارت ۵۵۴
پرسش
Trace water from soil to the atmosphere through a plant.
پاسخ
Soil → root hairs → root tissues → xylem → leaf mesophyll → leaf air spaces → stomata → atmosphere.
کارت ۵۵۵
پرسش
Why may root cells use active transport to absorb mineral ions?
پاسخ
Ion concentrations can be lower in soil than in root cells, so uptake must occur against a gradient.
کارت ۵۵۶
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Why do large multicellular organisms need bulk transport systems?
پاسخ
Their low surface-area-to-volume ratio and long diffusion distances make diffusion alone too slow for whole-body supply.
کارت ۵۵۷
پرسش
Why does hemoglobin unload more oxygen in actively respiring tissues?
پاسخ
Lower oxygen and often higher carbon dioxide and acidity reduce hemoglobin's oxygen affinity.
کارت ۵۵۸
پرسش
How does transpiration pull water upward through xylem?
پاسخ
Evaporation lowers leaf water potential and creates tension; cohesion transmits the pull through the continuous water column.
کارت ۵۵۹
پرسش
How do wind and low humidity generally affect transpiration?
پاسخ
Both maintain a steep water-vapor gradient outside the leaf, increasing transpiration if stomata remain open.
کارت ۵۶۰
پرسش
What drives mass flow in phloem?
پاسخ
Sugar loading draws in water and raises pressure at a source; unloading lowers pressure at a sink, producing bulk flow.
کارت ۵۶۱
پرسش
Can the same plant organ be a source at one time and a sink at another?
پاسخ
Yes. A storage organ may import sugars while filling and export them later during growth or germination.
کارت ۵۶۲
پرسش
What is a neuron?
پاسخ
An excitable cell specialized to receive, process, and transmit information.
کارت ۵۶۳
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What is a sensory neuron?
پاسخ
A neuron carrying information from a receptor toward the central nervous system.
کارت ۵۶۴
پرسش
What is a motor neuron?
پاسخ
A neuron carrying commands from the central nervous system to an effector.
کارت ۵۶۵
پرسش
What is the resting potential?
پاسخ
The voltage difference across an unstimulated neuron's membrane, with the inside negative relative to outside.
کارت ۵۶۶
پرسش
Which term describes an excitable information-transmitting cell?
پاسخ
a neuron
کارت ۵۶۷
پرسش
Which term describes a neuron carrying receptor information to the CNS?
پاسخ
a sensory neuron
کارت ۵۶۸
پرسش
Which term describes a neuron carrying CNS commands to an effector?
پاسخ
a motor neuron
کارت ۵۶۹
پرسش
Which term describes the negative-inside voltage of an unstimulated neuron?
پاسخ
the resting potential
کارت ۵۷۰
پرسش
What is an action potential?
پاسخ
A brief, self-propagating reversal and restoration of membrane potential along an excitable membrane.
کارت ۵۷۱
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What is depolarization?
پاسخ
A change that makes membrane potential less negative, and during an action potential often positive.
کارت ۵۷۲
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What is repolarization?
پاسخ
Return of membrane potential toward its resting negative value after depolarization.
کارت ۵۷۳
پرسش
What is a synapse?
پاسخ
A junction where one cell communicates with another cell.
کارت ۵۷۴
پرسش
Which term describes a brief propagating change in neuron membrane voltage?
پاسخ
an action potential
کارت ۵۷۵
پرسش
Which term describes a membrane-voltage change toward a less negative value?
پاسخ
depolarization
کارت ۵۷۶
پرسش
Which term describes return toward resting membrane voltage?
پاسخ
repolarization
کارت ۵۷۷
پرسش
Which term describes a communication junction between cells?
پاسخ
a synapse
کارت ۵۷۸
پرسش
What is a neurotransmitter?
پاسخ
A chemical released by a neuron that changes the activity of a target cell.
کارت ۵۷۹
پرسش
What is the refractory period?
پاسخ
A brief period after an action potential when another is impossible or requires a stronger stimulus.
کارت ۵۸۰
پرسش
What is myelin?
پاسخ
An insulating sheath around some axons that speeds impulse conduction.
کارت ۵۸۱
پرسش
What happens when membrane depolarization reaches threshold?
پاسخ
Voltage-gated channels trigger the self-amplifying events of an action potential.
کارت ۵۸۲
پرسش
Which term describes a neuron-released signaling chemical?
پاسخ
a neurotransmitter
کارت ۵۸۳
پرسش
Which term describes the recovery interval after an action potential?
پاسخ
the refractory period
کارت ۵۸۴
پرسش
Which term describes the insulating axon sheath?
پاسخ
myelin
کارت ۵۸۵
پرسش
What does the all-or-none principle mean for an action potential?
پاسخ
Once threshold is reached, the action potential has a characteristic size; stronger stimuli increase frequency, not its amplitude.
کارت ۵۸۶
پرسش
How does myelin increase conduction speed?
پاسخ
Depolarizing current travels rapidly beneath myelin and action potentials regenerate mainly at gaps in the sheath.
کارت ۵۸۷
پرسش
What is the basic sequence at a chemical synapse?
پاسخ
An impulse triggers neurotransmitter release; it diffuses across the cleft, binds receptors, and alters the postsynaptic cell.
کارت ۵۸۸
پرسش
Why can a reflex response be rapid?
پاسخ
A short neural pathway produces an automatic response without waiting for conscious processing.
کارت ۵۸۹
پرسش
What is sensory transduction?
پاسخ
Conversion of a physical or chemical stimulus into an electrical signal in a receptor cell.
کارت ۵۹۰
پرسش
How does an action potential propagate along an axon?
پاسخ
Local current depolarizes the next membrane region to threshold, opening voltage-gated channels there.
کارت ۵۹۱
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Why does an action potential normally travel in one direction along an axon?
پاسخ
The membrane just behind it is refractory and cannot immediately fire again.
کارت ۵۹۲
پرسش
How is neurotransmitter action ended?
پاسخ
The transmitter is removed by enzymatic breakdown, reuptake, or diffusion away.
کارت ۵۹۳
پرسش
What is sensory adaptation?
پاسخ
Reduced receptor or neural response during a constant, unchanging stimulus.
کارت ۵۹۴
پرسش
How can a drug alter synaptic transmission?
پاسخ
It may mimic or block a transmitter, change its release, or change its removal from the synaptic cleft.
کارت ۵۹۵
پرسش
What is an organ system?
پاسخ
A group of organs coordinating to perform major functions for an organism.
کارت ۵۹۶
پرسش
What is a hormone?
پاسخ
A signaling molecule released into transport fluid and acting on target cells with suitable receptors.
کارت ۵۹۷
پرسش
What is an endocrine gland?
پاسخ
A gland that secretes hormones into extracellular fluid and blood rather than through a duct.
کارت ۵۹۸
پرسش
What is a hormone target cell?
پاسخ
A cell able to respond because it has the appropriate receptor.
کارت ۵۹۹
پرسش
Which term describes a coordinated group of organs?
پاسخ
an organ system
کارت ۶۰۰
پرسش
Which term describes a long-distance chemical messenger carried in body fluid?
پاسخ
a hormone
کارت ۶۰۱
پرسش
Which term describes a ductless hormone-secreting gland?
پاسخ
an endocrine gland
کارت ۶۰۲
پرسش
Which term describes a cell with a receptor for a particular hormone?
پاسخ
a hormone target cell
کارت ۶۰۳
پرسش
What is digestion?
پاسخ
Mechanical and chemical breakdown of food into molecules small enough to absorb.
کارت ۶۰۴
پرسش
What is absorption?
پاسخ
Movement of digested nutrients across an exchange surface into blood or lymph.
کارت ۶۰۵
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What is peristalsis?
پاسخ
Coordinated waves of smooth-muscle contraction that move material through the digestive tract.
کارت ۶۰۶
پرسش
What is an intestinal villus?
پاسخ
A finger-like projection increasing the absorptive surface of the small intestine.
کارت ۶۰۷
پرسش
Which term describes breakdown of food into absorbable molecules?
پاسخ
digestion
کارت ۶۰۸
پرسش
Which term describes movement of digested nutrients into transport fluids?
پاسخ
absorption
کارت ۶۰۹
پرسش
Which term describes wave-like gut contractions moving contents?
پاسخ
peristalsis
کارت ۶۱۰
پرسش
Which term describes a finger-like intestinal absorption projection?
پاسخ
an intestinal villus
کارت ۶۱۱
پرسش
What is excretion?
پاسخ
Removal of metabolic waste products from the body.
کارت ۶۱۲
پرسش
What is a nephron?
پاسخ
The microscopic functional unit of the kidney that filters blood and modifies filtrate into urine.
کارت ۶۱۳
پرسش
What is ultrafiltration?
پاسخ
Pressure-driven filtration of small molecules from blood into a kidney capsule while cells and most proteins remain in blood.
کارت ۶۱۴
پرسش
What is selective reabsorption?
پاسخ
Recovery of useful substances and regulated amounts of water and ions from kidney filtrate into blood.
کارت ۶۱۵
پرسش
Which term describes removal of metabolic wastes?
پاسخ
excretion
کارت ۶۱۶
پرسش
Which term describes the kidney's microscopic functional unit?
پاسخ
a nephron
کارت ۶۱۷
پرسش
Which term describes pressure filtration at the start of a nephron?
پاسخ
ultrafiltration
کارت ۶۱۸
پرسش
Which term describes return of useful substances from kidney filtrate to blood?
پاسخ
selective reabsorption
کارت ۶۱۹
پرسش
What is skeletal muscle?
پاسخ
Striated voluntary muscle attached to the skeleton and used for movement and posture.
کارت ۶۲۰
پرسش
What is an antagonistic muscle pair?
پاسخ
Two muscles producing opposite movements at a joint because muscles pull but do not push.
کارت ۶۲۱
پرسش
How do nervous and endocrine signaling generally differ?
پاسخ
Neural signals are rapid and targeted; hormonal signals are usually slower, longer-lasting, and distributed through body fluids.
کارت ۶۲۲
پرسش
Why does a circulating hormone affect only some cells?
پاسخ
Only target cells express receptors that recognize the hormone and activate a response.
کارت ۶۲۳
پرسش
Which term describes voluntary striated muscle that moves the skeleton?
پاسخ
skeletal muscle
کارت ۶۲۴
پرسش
Which term describes two muscles producing opposite joint movements?
پاسخ
an antagonistic muscle pair
کارت ۶۲۵
پرسش
What is the final absorbable product of most dietary carbohydrate digestion?
پاسخ
Monosaccharides, especially glucose.
کارت ۶۲۶
پرسش
What are the main absorbable products of protein digestion?
پاسخ
Amino acids and small peptides that are completed to amino acids during absorption.
کارت ۶۲۷
پرسش
How is the small intestine adapted for absorption?
پاسخ
Folds, villi, and microvilli increase area; a thin epithelium, rich blood supply, and lymph vessels support transport.
کارت ۶۲۸
پرسش
Name three integrative roles of the liver.
پاسخ
It processes absorbed nutrients, regulates blood chemistry, detoxifies substances, produces bile, and converts ammonia to urea; any three are sufficient.
کارت ۶۲۹
پرسش
Why are blood cells and most plasma proteins absent from normal kidney filtrate?
پاسخ
They are too large to cross the filtration barrier.
کارت ۶۳۰
پرسش
How do muscles move a bone at a joint?
پاسخ
Contraction shortens the muscle, pulling through a tendon on the bone.
کارت ۶۳۱
پرسش
Why are antagonistic muscles needed at many joints?
پاسخ
A muscle can pull in one direction but cannot push itself back, so an opposing muscle produces the reverse movement.
کارت ۶۳۲
پرسش
Why must organ systems be integrated rather than acting independently?
پاسخ
Each system depends on materials, signals, waste removal, and stable conditions supplied by other systems.
کارت ۶۳۳
پرسش
Why do many absorbed lipids enter lymph before blood?
پاسخ
Intestinal cells package them into lipoprotein particles too large to enter ordinary blood capillaries directly.
کارت ۶۳۴
پرسش
Why is glucose normally absent from final urine?
پاسخ
Filtered glucose is selectively reabsorbed into blood when transporter capacity is not exceeded.
کارت ۶۳۵
پرسش
How do respiratory, circulatory, and muscular systems cooperate during exercise?
پاسخ
Ventilation supplies oxygen, circulation transports gases and fuels, and muscles use ATP while returning carbon dioxide, heat, and metabolites.
کارت ۶۳۶
پرسش
How do liver, circulation, and kidneys cooperate in nitrogen-waste removal?
پاسخ
The liver converts toxic ammonia to urea, blood carries urea, and kidneys filter and excrete it.
کارت ۶۳۷
پرسش
What is a pathogen?
پاسخ
A biological agent capable of causing disease.
کارت ۶۳۸
پرسش
What is an antigen?
پاسخ
A molecule recognized specifically by an antibody or lymphocyte receptor.
کارت ۶۳۹
پرسش
What is innate immunity?
پاسخ
Rapid, nonspecific defense mechanisms present without prior exposure.
کارت ۶۴۰
پرسش
What is adaptive immunity?
پاسخ
Specific defense that develops through lymphocyte activation and can form memory.
کارت ۶۴۱
پرسش
Which term describes a disease-causing biological agent?
پاسخ
a pathogen
کارت ۶۴۲
پرسش
Which term describes a molecule specifically recognized by adaptive immune receptors?
پاسخ
an antigen
کارت ۶۴۳
پرسش
Which term describes rapid nonspecific immune defense?
پاسخ
innate immunity
کارت ۶۴۴
پرسش
Which term describes specific immune defense capable of memory?
پاسخ
adaptive immunity
کارت ۶۴۵
پرسش
What is a phagocyte?
پاسخ
A cell that engulfs and digests microbes, particles, or damaged cells.
کارت ۶۴۶
پرسش
What is a lymphocyte?
پاسخ
An adaptive immune cell with receptors specific to particular antigens.
کارت ۶۴۷
پرسش
What is an antibody?
پاسخ
A secreted immunoglobulin that binds a specific antigen.
کارت ۶۴۸
پرسش
What is a B lymphocyte?
پاسخ
A lymphocyte that can differentiate into antibody-secreting plasma cells and memory cells.
کارت ۶۴۹
پرسش
Which term describes an engulfing immune cell?
پاسخ
a phagocyte
کارت ۶۵۰
پرسش
Which term describes an antigen-specific adaptive immune cell?
پاسخ
a lymphocyte
کارت ۶۵۱
پرسش
Which term describes a secreted antigen-binding immunoglobulin?
پاسخ
an antibody
کارت ۶۵۲
پرسش
Which term describes the lymphocyte lineage that produces antibody-secreting cells?
پاسخ
a B lymphocyte
کارت ۶۵۳
پرسش
What is a helper T cell?
پاسخ
A lymphocyte that coordinates immune responses through contact signals and cytokines.
کارت ۶۵۴
پرسش
What is an immune memory cell?
پاسخ
A long-lived lymphocyte that responds rapidly after re-exposure to its antigen.
کارت ۶۵۵
پرسش
What is vaccination?
پاسخ
Deliberate exposure to a safe form or component of an antigen to generate protective immune memory.
کارت ۶۵۶
پرسش
What is an antibiotic?
پاسخ
A substance that kills bacteria or inhibits their growth at clinically useful doses.
کارت ۶۵۷
پرسش
Which term describes the T cell that coordinates other immune cells?
پاسخ
a helper T cell
کارت ۶۵۸
پرسش
Which term describes a long-lived lymphocyte enabling faster re-exposure response?
پاسخ
an immune memory cell
کارت ۶۵۹
پرسش
Which term describes safe antigen exposure used to create immune memory?
پاسخ
vaccination
کارت ۶۶۰
پرسش
Which term describes a drug acting against bacteria?
پاسخ
an antibiotic
کارت ۶۶۱
پرسش
What are examples of first-line defenses against pathogens?
پاسخ
Intact skin, mucus, cilia, antimicrobial secretions, stomach acidity, and competing microbiota.
کارت ۶۶۲
پرسش
How does inflammation help defend damaged tissue?
پاسخ
It increases local blood flow and vessel permeability and recruits immune cells and defensive molecules.
کارت ۶۶۳
پرسش
What happens during phagocytosis?
پاسخ
A cell surrounds a particle in a vesicle, then fuses it with digestive compartments to destroy or process it.
کارت ۶۶۴
پرسش
How can antibodies help eliminate a pathogen?
پاسخ
They can neutralize targets, block attachment, clump particles, and mark them for phagocytosis or complement attack.
کارت ۶۶۵
پرسش
Why can a vaccine generate protection without causing the full disease?
پاسخ
It presents antigen in a weakened, inactivated, partial, or encoded form that stimulates immunity with much lower risk.
کارت ۶۶۶
پرسش
Why do antibiotics not treat viral infections?
پاسخ
Viruses lack the bacterial structures and independent metabolic processes targeted by antibiotics.
کارت ۶۶۷
پرسش
What determines the antigen specificity of a lymphocyte?
پاسخ
The molecular shape and chemistry of its unique surface receptor.
کارت ۶۶۸
پرسش
What is clonal selection?
پاسخ
An antigen activates lymphocytes with matching receptors, causing them to proliferate and differentiate.
کارت ۶۶۹
پرسش
Why is a secondary adaptive immune response usually faster and stronger?
پاسخ
Memory cells are more numerous and activate rapidly, producing effective cells and antibodies sooner.
کارت ۶۷۰
پرسش
How can high vaccination coverage protect some unvaccinated people?
پاسخ
Reduced transmission makes encounters with infectious individuals less likely, though protection is incomplete and pathogen-dependent.
کارت ۶۷۱
پرسش
How does antibiotic use select for resistant bacteria?
پاسخ
Susceptible bacteria are removed while resistant variants survive and reproduce, increasing resistance-allele frequency.
کارت ۶۷۲
پرسش
Why can unnecessary or incomplete antibiotic exposure promote resistance?
پاسخ
It creates selection favoring resistant cells while potentially leaving surviving bacteria to multiply and spread.
کارت ۶۷۳
پرسش
What is an allergy?
پاسخ
An immune response to a normally harmless antigen that causes tissue symptoms or damage.
کارت ۶۷۴
پرسش
What is asexual reproduction?
پاسخ
Production of offspring from one parent without fusion of gametes.
کارت ۶۷۵
پرسش
What is sexual reproduction?
پاسخ
Production of offspring involving fusion of haploid gametes.
کارت ۶۷۶
پرسش
What is a gamete?
پاسخ
A haploid reproductive cell able to fuse with another gamete.
کارت ۶۷۷
پرسش
What is fertilization?
پاسخ
Fusion of gamete nuclei to form a diploid zygote.
کارت ۶۷۸
پرسش
Which term describes reproduction without gamete fusion?
پاسخ
asexual reproduction
کارت ۶۷۹
پرسش
Which term describes reproduction involving gamete fusion?
پاسخ
sexual reproduction
کارت ۶۸۰
پرسش
Which term describes a haploid reproductive cell?
پاسخ
a gamete
کارت ۶۸۱
پرسش
Which term describes fusion of gamete nuclei?
پاسخ
fertilization
کارت ۶۸۲
پرسش
What is a zygote?
پاسخ
The diploid cell formed by fertilization.
کارت ۶۸۳
پرسش
What is meiosis?
پاسخ
Cell division that halves chromosome number and usually produces genetically varied haploid cells.
کارت ۶۸۴
پرسش
What is ovulation?
پاسخ
Release of a secondary oocyte from an ovary.
کارت ۶۸۵
پرسش
What is implantation?
پاسخ
Attachment and embedding of an early embryo in the uterine lining.
کارت ۶۸۶
پرسش
Which term describes the first diploid cell after fertilization?
پاسخ
a zygote
کارت ۶۸۷
پرسش
Which term describes division producing varied haploid cells?
پاسخ
meiosis
کارت ۶۸۸
پرسش
Which term describes release of an oocyte from an ovary?
پاسخ
ovulation
کارت ۶۸۹
پرسش
Which term describes embedding of an early embryo in the uterine lining?
پاسخ
implantation
کارت ۶۹۰
پرسش
What is the placenta?
پاسخ
A temporary organ that exchanges materials between maternal and fetal blood supplies without normally mixing them directly.
کارت ۶۹۱
پرسش
What is pollination?
پاسخ
Transfer of pollen from an anther to a receptive stigma.
کارت ۶۹۲
پرسش
Why does sexual reproduction usually produce more genetic variation than asexual reproduction?
پاسخ
Meiosis reshuffles alleles and random fertilization combines genomes from two gametes.
کارت ۶۹۳
پرسش
Why must gametes be haploid?
پاسخ
Fusion of two haploid gametes restores the diploid chromosome number instead of doubling it each generation.
کارت ۶۹۴
پرسش
Which term describes the maternal-fetal exchange organ?
پاسخ
the placenta
کارت ۶۹۵
پرسش
Which term describes transfer of pollen to a stigma?
پاسخ
pollination
کارت ۶۹۶
پرسش
What are major roles of FSH in the ovarian cycle?
پاسخ
It stimulates follicle development and supports estrogen secretion.
کارت ۶۹۷
پرسش
What is a major role of the mid-cycle LH surge?
پاسخ
It triggers ovulation and formation of the corpus luteum.
کارت ۶۹۸
پرسش
How does estrogen contribute to the uterine cycle?
پاسخ
It promotes repair and thickening of the uterine lining after menstruation.
کارت ۶۹۹
پرسش
How does progesterone contribute to the uterine cycle?
پاسخ
It maintains a thick, secretory uterine lining after ovulation.
کارت ۷۰۰
پرسش
Where does human fertilization usually occur?
پاسخ
In an oviduct, before the early embryo reaches the uterus.
کارت ۷۰۱
پرسش
What happens after compatible pollen reaches a flower's stigma?
پاسخ
A pollen tube grows toward an ovule and delivers male nuclei for fertilization.
کارت ۷۰۲
پرسش
Why does menstruation usually begin if pregnancy does not occur?
پاسخ
The corpus luteum degenerates, progesterone and estrogen fall, and the uterine lining is no longer maintained.
کارت ۷۰۳
پرسش
What substances commonly cross the placenta between mother and fetus?
پاسخ
Oxygen and nutrients move toward the fetus; carbon dioxide and nitrogenous wastes move toward the mother.
کارت ۷۰۴
پرسش
How can contraception prevent pregnancy in different ways?
پاسخ
Methods can inhibit ovulation, block sperm from reaching an egg, prevent fertilization, or permanently interrupt the reproductive ducts.
کارت ۷۰۵
پرسش
What is homeostasis?
پاسخ
Maintenance of internal conditions within ranges compatible with normal function despite change.
کارت ۷۰۶
پرسش
What is negative feedback?
پاسخ
Control in which a deviation triggers responses that oppose the original change.
کارت ۷۰۷
پرسش
What is a set point?
پاسخ
The target value or range around which a regulated variable is maintained.
کارت ۷۰۸
پرسش
What is a homeostatic receptor?
پاسخ
A sensor that detects a change in a regulated variable.
کارت ۷۰۹
پرسش
Which term describes maintenance of a stable functional internal environment?
پاسخ
homeostasis
کارت ۷۱۰
پرسش
Which term describes feedback that counteracts a deviation?
پاسخ
negative feedback
کارت ۷۱۱
پرسش
Which term describes the target around which a variable is regulated?
پاسخ
a set point
کارت ۷۱۲
پرسش
Which term describes the sensor in a feedback system?
پاسخ
a homeostatic receptor
کارت ۷۱۳
پرسش
What is a control center?
پاسخ
The component that compares information with a target and coordinates a response.
کارت ۷۱۴
پرسش
What is an effector?
پاسخ
A muscle, gland, or other component that carries out a control response.
کارت ۷۱۵
پرسش
What is thermoregulation?
پاسخ
Control of body temperature within a functional range.
کارت ۷۱۶
پرسش
What is vasodilation?
پاسخ
Widening of blood vessels, often increasing blood flow near the skin.
کارت ۷۱۷
پرسش
Which term describes the feedback component that evaluates input and directs a response?
پاسخ
a control center
کارت ۷۱۸
پرسش
Which term describes the component that executes a physiological response?
پاسخ
an effector
کارت ۷۱۹
پرسش
Which term describes physiological regulation of body temperature?
پاسخ
thermoregulation
کارت ۷۲۰
پرسش
Which term describes widening of blood vessels?
پاسخ
vasodilation
کارت ۷۲۱
پرسش
What is vasoconstriction?
پاسخ
Narrowing of blood vessels, often reducing blood flow near the skin.
کارت ۷۲۲
پرسش
What is insulin?
پاسخ
A pancreatic hormone that lowers elevated blood glucose by promoting uptake and storage.
کارت ۷۲۳
پرسش
What is glucagon?
پاسخ
A pancreatic hormone that raises low blood glucose by promoting release of stored fuel.
کارت ۷۲۴
پرسش
What are the main components of a homeostatic feedback loop?
پاسخ
A regulated variable, receptor, control center, effectors, and responses that alter the variable.
کارت ۷۲۵
پرسش
Which term describes narrowing of blood vessels?
پاسخ
vasoconstriction
کارت ۷۲۶
پرسش
Which term describes the pancreatic hormone that lowers blood glucose?
پاسخ
insulin
کارت ۷۲۷
پرسش
Which term describes the pancreatic hormone that raises blood glucose?
پاسخ
glucagon
کارت ۷۲۸
پرسش
What happens when blood glucose rises after a meal?
پاسخ
Insulin secretion increases, promoting glucose uptake and storage so blood glucose falls toward its normal range.
کارت ۷۲۹
پرسش
What happens when blood glucose falls during fasting?
پاسخ
Glucagon secretion increases, promoting glycogen breakdown and glucose release by the liver.
کارت ۷۳۰
پرسش
How does sweating cool the body?
پاسخ
Evaporation of water from skin transfers heat to the environment.
کارت ۷۳۱
پرسش
How does skin vasodilation increase heat loss?
پاسخ
It brings more warm blood near the surface, increasing transfer of heat to the environment.
کارت ۷۳۲
پرسش
How does shivering warm the body?
پاسخ
Rapid involuntary muscle contractions increase respiration and heat production.
کارت ۷۳۳
پرسش
Does homeostasis keep internal conditions perfectly constant?
پاسخ
No. Variables fluctuate within controlled ranges around target values.
کارت ۷۳۴
پرسش
How does ADH help conserve water?
پاسخ
It increases water permeability in kidney collecting ducts, so more water is reabsorbed and urine becomes more concentrated.
کارت ۷۳۵
پرسش
How should ADH secretion change during dehydration?
پاسخ
It should increase, promoting greater water reabsorption by the kidneys.
کارت ۷۳۶
پرسش
How does positive feedback differ from negative feedback?
پاسخ
Positive feedback amplifies a change until an endpoint; negative feedback opposes a change and stabilizes a variable.
کارت ۷۳۷
پرسش
Why can diabetes mellitus cause persistently high blood glucose?
پاسخ
Insulin production may be insufficient or target cells may respond poorly to insulin.
کارت ۷۳۸
پرسش
What is biological evolution?
پاسخ
Change in heritable characteristics or allele frequencies of a population across generations.
کارت ۷۳۹
پرسش
What is allele frequency?
پاسخ
The proportion of gene copies in a population represented by a particular allele.
کارت ۷۴۰
پرسش
What is microevolution?
پاسخ
Evolutionary change in allele frequencies within populations over relatively short timescales.
کارت ۷۴۱
پرسش
What is speciation?
پاسخ
Evolutionary formation of new species.
کارت ۷۴۲
پرسش
Which term describes change in a population's heritable composition across generations?
پاسخ
biological evolution
کارت ۷۴۳
پرسش
Which term describes the proportion of a population's gene copies that are one allele?
پاسخ
allele frequency
کارت ۷۴۴
پرسش
Which term describes short-timescale allele-frequency change within populations?
پاسخ
microevolution
کارت ۷۴۵
پرسش
Which term describes formation of new species?
پاسخ
speciation
کارت ۷۴۶
پرسش
What is reproductive isolation?
پاسخ
Barriers that prevent or greatly reduce gene flow between populations.
کارت ۷۴۷
پرسش
What is allopatric speciation?
پاسخ
Speciation after populations become geographically separated and diverge.
کارت ۷۴۸
پرسش
What is sympatric speciation?
پاسخ
Speciation without geographic separation, through reproductive isolation within the same area.
کارت ۷۴۹
پرسش
What are homologous structures?
پاسخ
Structures similar because they were inherited from a common ancestor, even if their functions differ.
کارت ۷۵۰
پرسش
Which term describes barriers reducing gene flow between populations?
پاسخ
reproductive isolation
کارت ۷۵۱
پرسش
Which term describes speciation following geographic separation?
پاسخ
allopatric speciation
کارت ۷۵۲
پرسش
Which term describes speciation within the same geographic area?
پاسخ
sympatric speciation
کارت ۷۵۳
پرسش
Which term describes structures similar through common ancestry?
پاسخ
homologous structures
کارت ۷۵۴
پرسش
What are analogous structures?
پاسخ
Structures with similar functions that evolved independently rather than from the same ancestral structure.
کارت ۷۵۵
پرسش
What is a common ancestor?
پاسخ
An ancestral population from which two or more descendant lineages evolved.
کارت ۷۵۶
پرسش
How does the fossil record provide evidence for evolution?
پاسخ
It documents organisms from different times, including appearance, change, persistence, and extinction of lineages.
کارت ۷۵۷
پرسش
How do DNA and protein sequences provide evidence of common ancestry?
پاسخ
Shared sequences are inherited; greater similarity generally indicates more recent common ancestry.
کارت ۷۵۸
پرسش
Which term describes functionally similar structures of independent evolutionary origin?
پاسخ
analogous structures
کارت ۷۵۹
پرسش
Which term describes an ancestral population shared by descendant lineages?
پاسخ
a common ancestor
کارت ۷۶۰
پرسش
What is the evolutionary significance of extinction?
پاسخ
It permanently ends a lineage and can alter ecological opportunities and the future diversification of survivors.
کارت ۷۶۱
پرسش
Do individual organisms evolve during their lifetimes?
پاسخ
No. Individuals develop and acclimate; evolution is heritable change in populations across generations.
کارت ۷۶۲
پرسش
Why is evolution represented as a branching tree rather than a ladder?
پاسخ
Lineages split from common ancestors; living species are not arranged as stages toward a single goal.
کارت ۷۶۳
پرسش
How can island species support evolutionary explanations?
پاسخ
Their similarities to nearby mainland ancestors and unique local adaptations fit divergence after colonization and isolation.
کارت ۷۶۴
پرسش
How can geographic isolation lead to reproductive isolation?
پاسخ
Separated populations accumulate different mutations and experience different selection and drift until interbreeding is reduced.
کارت ۷۶۵
پرسش
Why can continuing gene flow slow speciation?
پاسخ
Movement of alleles between populations counteracts genetic divergence.
کارت ۷۶۶
پرسش
Why can unrelated species evolve similar traits?
پاسخ
Similar environmental challenges can favor similar functional solutions through convergent evolution.
کارت ۷۶۷
پرسش
Which parts of evolution are random and which are nonrandom?
پاسخ
Mutation and many sampling effects are random with respect to need; natural selection nonrandomly favors variants that reproduce better in a given environment.
کارت ۷۶۸
پرسش
What is conservation biology?
پاسخ
The science and practice of protecting biodiversity, ecological processes, and evolutionary potential.
کارت ۷۶۹
پرسش
What is habitat fragmentation?
پاسخ
Division of continuous habitat into smaller, isolated patches.
کارت ۷۷۰
پرسش
What is an endangered species?
پاسخ
A species facing a high risk of extinction in the wild.
کارت ۷۷۱
پرسش
What is in situ conservation?
پاسخ
Protection of species in their natural habitats and ecological communities.
کارت ۷۷۲
پرسش
Which term describes the protection of biodiversity and ecological processes?
پاسخ
conservation biology
کارت ۷۷۳
پرسش
Which term describes division of habitat into isolated patches?
پاسخ
habitat fragmentation
کارت ۷۷۴
پرسش
Which term describes a species at high risk of extinction?
پاسخ
an endangered species
کارت ۷۷۵
پرسش
Which term describes conservation within natural habitat?
پاسخ
in situ conservation
کارت ۷۷۶
پرسش
What is ex situ conservation?
پاسخ
Protection of organisms or genetic material outside the natural habitat.
کارت ۷۷۷
پرسش
What is a population bottleneck?
پاسخ
A sharp population reduction that can remove genetic variation by chance.
کارت ۷۷۸
پرسش
What is a wildlife corridor?
پاسخ
Habitat connecting isolated patches to permit movement and gene flow.
کارت ۷۷۹
پرسش
What major human-driven processes threaten biodiversity?
پاسخ
Habitat loss, overexploitation, invasive species, pollution, and climate change.
کارت ۷۸۰
پرسش
Which term describes conservation outside natural habitat?
پاسخ
ex situ conservation
کارت ۷۸۱
پرسش
Which term describes a severe population reduction that loses genetic diversity?
پاسخ
a population bottleneck
کارت ۷۸۲
پرسش
Which term describes habitat linking isolated populations?
پاسخ
a wildlife corridor
کارت ۷۸۳
پرسش
What makes a protected area more effective than a boundary alone?
پاسخ
Adequate size, representative habitat, enforcement, connectivity, local support, and management of external threats.
کارت ۷۸۴
پرسش
Why is long-term population monitoring important in conservation?
پاسخ
It reveals trends, tests whether management works, and provides early warning of decline.
کارت ۷۸۵
پرسش
How can ecosystem services support the case for conservation?
پاسخ
Healthy ecosystems provide benefits such as pollination, water purification, carbon storage, soil formation, and cultural value.
کارت ۷۸۶
پرسش
Why are very small populations especially vulnerable to extinction?
پاسخ
Chance events, inbreeding, low genetic diversity, and difficulty finding mates can reinforce decline.
کارت ۷۸۷
پرسش
What are benefits and limits of captive-breeding programs?
پاسخ
They can prevent immediate extinction and manage breeding, but may lose diversity, alter behavior, and fail without safe habitat for release.
کارت ۷۸۸
پرسش
Why can controlling an invasive species aid conservation?
پاسخ
It can reduce predation, competition, disease, or habitat alteration affecting native species.
کارت ۷۸۹
پرسش
Why must conservation priorities consider more than species count?
پاسخ
Endemism, evolutionary distinctness, ecological roles, threat severity, feasibility, and human needs also matter.
کارت ۷۹۰
پرسش
What is an adaptation?
پاسخ
A heritable characteristic that increases reproductive success in a particular environment.
کارت ۷۹۱
پرسش
What is acclimation?
پاسخ
A reversible physiological or behavioral adjustment by an individual to environmental change.
کارت ۷۹۲
پرسش
What is a structural adaptation?
پاسخ
An inherited anatomical feature that improves performance in an environment.
کارت ۷۹۳
پرسش
What is a physiological adaptation?
پاسخ
An inherited functional or biochemical feature that improves performance in an environment.
کارت ۷۹۴
پرسش
Which term describes a heritable trait improving reproductive success in context?
پاسخ
an adaptation
کارت ۷۹۵
پرسش
Which term describes an individual's reversible adjustment to environmental change?
پاسخ
acclimation
کارت ۷۹۶
پرسش
Which term describes an adaptive anatomical feature?
پاسخ
a structural adaptation
کارت ۷۹۷
پرسش
Which term describes an adaptive functional or biochemical feature?
پاسخ
a physiological adaptation
کارت ۷۹۸
پرسش
What is a behavioral adaptation?
پاسخ
An inherited behavior pattern that improves survival or reproduction.
کارت ۷۹۹
پرسش
What is an environmental tolerance range?
پاسخ
The range of an abiotic condition within which an organism can survive and reproduce.
کارت ۸۰۰
پرسش
What is evolutionary fitness?
پاسخ
Relative contribution of an individual or genotype to future generations.
کارت ۸۰۱
پرسش
How can a thick cuticle and reduced leaves help a desert plant?
پاسخ
The cuticle lowers surface permeability, while smaller leaves reduce the area from which water can evaporate.
کارت ۸۰۲
پرسش
Which term describes an adaptive behavior pattern?
پاسخ
a behavioral adaptation
کارت ۸۰۳
پرسش
Which term describes the survivable range of an abiotic condition?
پاسخ
an environmental tolerance range
کارت ۸۰۴
پرسش
Which term describes relative reproductive contribution to future generations?
پاسخ
evolutionary fitness
کارت ۸۰۵
پرسش
How can a streamlined body adapt an aquatic animal to movement?
پاسخ
It reduces drag, lowering the energy needed to move through water.
کارت ۸۰۶
پرسش
Does an organism develop an adaptation because it needs one?
پاسخ
No. Heritable variants arise without regard to need, and selection changes their frequencies across generations.
کارت ۸۰۷
پرسش
Why may organisms from different thermal environments have enzymes with different temperature optima?
پاسخ
Selection favors protein structures that balance flexibility and stability under local temperatures.
کارت ۸۰۸
پرسش
Why is an adaptation rarely beneficial in every environment?
پاسخ
Traits carry costs and their advantage depends on local resources, competitors, predators, and physical conditions.
کارت ۸۰۹
پرسش
How does phenotypic plasticity differ from genetic adaptation?
پاسخ
Plasticity lets one genotype produce different phenotypes; adaptation is a heritable population trait shaped across generations.
کارت ۸۱۰
پرسش
What is local adaptation?
پاسخ
A population has higher fitness in its home environment than foreign populations because selection favored local traits.
کارت ۸۱۱
پرسش
What is an ecological niche?
پاسخ
The set of environmental conditions, resources, interactions, and functional roles associated with a species.
کارت ۸۱۲
پرسش
What is a habitat?
پاسخ
The physical place or environment where an organism lives.
کارت ۸۱۳
پرسش
What is a fundamental niche?
پاسخ
The full range of conditions and resources a species could use without limiting biotic interactions.
کارت ۸۱۴
پرسش
What is a realized niche?
پاسخ
The conditions and resources a species actually uses after competition and other interactions.
کارت ۸۱۵
پرسش
Which term describes a species' environmental requirements and ecological role?
پاسخ
an ecological niche
کارت ۸۱۶
پرسش
Which term describes the place where an organism lives?
پاسخ
a habitat
کارت ۸۱۷
پرسش
Which term describes the potential niche without limiting biotic interactions?
پاسخ
a fundamental niche
کارت ۸۱۸
پرسش
Which term describes the niche actually occupied in nature?
پاسخ
a realized niche
کارت ۸۱۹
پرسش
What is competition?
پاسخ
An interaction in which organisms reduce one another's access to a limited resource.
کارت ۸۲۰
پرسش
What is mutualism?
پاسخ
An interaction in which both participating species benefit.
کارت ۸۲۱
پرسش
What is predation?
پاسخ
An interaction in which one organism kills and consumes another.
کارت ۸۲۲
پرسش
How does a habitat differ from a niche?
پاسخ
A habitat is where an organism lives; a niche includes how it uses conditions and resources and interacts there.
کارت ۸۲۳
پرسش
Which term describes an interaction over a limited resource that harms both competitors?
پاسخ
competition
کارت ۸۲۴
پرسش
Which term describes an interspecific interaction benefiting both partners?
پاسخ
mutualism
کارت ۸۲۵
پرسش
Which term describes an interaction where one organism kills and eats another?
پاسخ
predation
کارت ۸۲۶
پرسش
What kinds of factors define a niche?
پاسخ
Abiotic factors such as temperature and moisture, plus biotic factors such as food, competitors, predators, and partners.
کارت ۸۲۷
پرسش
What does competitive exclusion predict?
پاسخ
Species with effectively identical niches cannot coexist indefinitely under stable conditions; one is excluded or niches diverge.
کارت ۸۲۸
پرسش
How can resource partitioning reduce competition?
پاسخ
Species use different resources, places, or times, reducing niche overlap.
کارت ۸۲۹
پرسش
What is a keystone species?
پاسخ
A species whose effect on community structure is disproportionately large relative to its abundance.
کارت ۸۳۰
پرسش
Why can an introduced species expand rapidly in a new community?
پاسخ
It may encounter abundant resources, suitable climate, and fewer predators, pathogens, or competitors.
کارت ۸۳۱
پرسش
Can an organism alter the niche conditions of other species?
پاسخ
Yes. Ecosystem engineers modify habitat structure or resource availability, changing opportunities for other organisms.
کارت ۸۳۲
پرسش
What is a population?
پاسخ
Individuals of the same species living in the same area at the same time.
کارت ۸۳۳
پرسش
What is an ecological community?
پاسخ
Populations of different species living and interacting in an area.
کارت ۸۳۴
پرسش
What is an ecosystem?
پاسخ
A community together with its physical environment and their interactions.
کارت ۸۳۵
پرسش
What is carrying capacity?
پاسخ
The population size an environment can sustain over time under given conditions.
کارت ۸۳۶
پرسش
Which term describes same-species individuals sharing an area and time?
پاسخ
a population
کارت ۸۳۷
پرسش
Which term describes interacting populations of different species?
پاسخ
an ecological community
کارت ۸۳۸
پرسش
Which term describes a community plus its abiotic environment?
پاسخ
an ecosystem
کارت ۸۳۹
پرسش
Which term describes the long-term supportable population size?
پاسخ
carrying capacity
کارت ۸۴۰
پرسش
What is population density?
پاسخ
The number of individuals per unit area or volume.
کارت ۸۴۱
پرسش
What is a limiting factor?
پاسخ
A resource or condition that restricts population growth or distribution.
کارت ۸۴۲
پرسش
What is a density-dependent factor?
پاسخ
A factor whose effect strengthens as population density increases.
کارت ۸۴۳
پرسش
What is a density-independent factor?
پاسخ
A factor whose effect is not primarily determined by population density.
کارت ۸۴۴
پرسش
Which term describes individuals per unit area or volume?
پاسخ
population density
کارت ۸۴۵
پرسش
Which term describes a resource or condition restricting a population?
پاسخ
a limiting factor
کارت ۸۴۶
پرسش
Which term describes a factor with stronger effects at higher density?
پاسخ
a density-dependent factor
کارت ۸۴۷
پرسش
Which term describes a factor acting largely regardless of population density?
پاسخ
a density-independent factor
کارت ۸۴۸
پرسش
What is exponential population growth?
پاسخ
Growth at a constant per-capita rate, producing a J-shaped curve under ideal conditions.
کارت ۸۴۹
پرسش
What is logistic population growth?
پاسخ
Growth that slows as population size approaches carrying capacity, producing an S-shaped model.
کارت ۸۵۰
پرسش
What four processes directly change population size?
پاسخ
Births and immigration increase it; deaths and emigration decrease it.
کارت ۸۵۱
پرسش
Under what conditions can exponential growth occur temporarily?
پاسخ
Resources are abundant and limiting effects such as competition, disease, and predation are weak.
کارت ۸۵۲
پرسش
Which term describes J-shaped growth at constant per-capita rate?
پاسخ
exponential population growth
کارت ۸۵۳
پرسش
Which term describes S-shaped growth that slows near carrying capacity?
پاسخ
logistic population growth
کارت ۸۵۴
پرسش
Why is infectious disease often density dependent?
پاسخ
Close or frequent contact at high density increases transmission opportunities.
کارت ۸۵۵
پرسش
Give an example of a density-independent population factor.
پاسخ
A severe storm, wildfire, drought, or freeze can affect populations regardless of their initial density.
کارت ۸۵۶
پرسش
When is quadrat sampling useful?
پاسخ
For estimating abundance or frequency of sessile or slow-moving organisms in defined areas.
کارت ۸۵۷
پرسش
What can a transect reveal?
پاسخ
How species occurrence or abundance changes along an environmental gradient.
کارت ۸۵۸
پرسش
What can happen when a population overshoots carrying capacity?
پاسخ
Resource depletion may raise mortality or lower reproduction, causing decline or oscillation.
کارت ۸۵۹
پرسش
What is the basic mark–recapture estimate of population size?
پاسخ
First sample marked × second sample total ÷ marked individuals recaptured.
کارت ۸۶۰
پرسش
What assumptions improve a mark–recapture estimate?
پاسخ
Marks persist and do not affect survival, marked individuals mix, capture probability is similar, and the population is effectively closed.
کارت ۸۶۱
پرسش
Why does a correlation between two population variables not prove causation?
پاسخ
A third factor, reverse influence, chance, or biased sampling could produce the association.
کارت ۸۶۲
پرسش
What is a trophic level?
پاسخ
A feeding position in a food chain or web.
کارت ۸۶۳
پرسش
What is a producer?
پاسخ
An autotroph that converts inorganic carbon into organic matter.
کارت ۸۶۴
پرسش
What is a consumer?
پاسخ
An organism obtaining energy and matter by eating other organisms or organic material.
کارت ۸۶۵
پرسش
What is a decomposer?
پاسخ
An organism that externally digests dead material and wastes and absorbs the products.
کارت ۸۶۶
پرسش
Which term describes a feeding position in an ecosystem?
پاسخ
a trophic level
کارت ۸۶۷
پرسش
Which term describes an autotroph forming organic matter?
پاسخ
a producer
کارت ۸۶۸
پرسش
Which term describes an organism feeding on other organic matter?
پاسخ
a consumer
کارت ۸۶۹
پرسش
Which term describes an organism digesting dead organic matter externally?
پاسخ
a decomposer
کارت ۸۷۰
پرسش
What is a food chain?
پاسخ
A linear representation of feeding and energy-transfer relationships.
کارت ۸۷۱
پرسش
What is a food web?
پاسخ
A network of interconnected feeding relationships in a community.
کارت ۸۷۲
پرسش
What is gross primary productivity?
پاسخ
The total rate at which producers capture energy into organic matter.
کارت ۸۷۳
پرسش
What is net primary productivity?
پاسخ
Producer energy stored as new biomass after subtracting producer respiration from gross primary productivity.
کارت ۸۷۴
پرسش
Which term describes a linear feeding sequence?
پاسخ
a food chain
کارت ۸۷۵
پرسش
Which term describes a network of connected food chains?
پاسخ
a food web
کارت ۸۷۶
پرسش
Which term describes the total producer energy-capture rate?
پاسخ
gross primary productivity
کارت ۸۷۷
پرسش
Which term describes producer biomass gain after respiration?
پاسخ
net primary productivity
کارت ۸۷۸
پرسش
What is ecological productivity?
پاسخ
The rate of biomass or energy production per unit area or volume.
کارت ۸۷۹
پرسش
What is a biogeochemical cycle?
پاسخ
Movement of an element or compound through organisms and the physical environment.
کارت ۸۸۰
پرسش
Why is less energy available at each higher trophic level?
پاسخ
Not all biomass is eaten or digested, and organisms use energy in respiration, movement, maintenance, and heat loss.
کارت ۸۸۱
پرسش
Why does energy flow rather than cycle through an ecosystem?
پاسخ
Energy enters mainly as light and ultimately disperses as heat, which ecosystems cannot fully recycle.
کارت ۸۸۲
پرسش
Which term describes the rate of biomass or energy production?
پاسخ
ecological productivity
کارت ۸۸۳
پرسش
Which term describes cycling of matter through living and nonliving reservoirs?
پاسخ
a biogeochemical cycle
کارت ۸۸۴
پرسش
Why can matter cycle through an ecosystem?
پاسخ
Atoms are conserved and repeatedly transferred among organisms, detritus, soil, water, and atmosphere.
کارت ۸۸۵
پرسش
Why is a pyramid of energy always upright?
پاسخ
Usable energy decreases between trophic levels because every transfer includes losses.
کارت ۸۸۶
پرسش
How are gross and net primary productivity related?
پاسخ
NPP = GPP − producer respiration.
کارت ۸۸۷
پرسش
How do decomposers support nutrient cycling?
پاسخ
They break down dead material and wastes, releasing inorganic nutrients for reuse.
کارت ۸۸۸
پرسش
What processes move carbon rapidly between organisms and the atmosphere?
پاسخ
Photosynthesis removes carbon dioxide; respiration, decomposition, and combustion release it.
کارت ۸۸۹
پرسش
Why is nitrogen fixation important?
پاسخ
It converts atmospheric nitrogen gas into forms that can enter biological nitrogen metabolism.
کارت ۸۹۰
پرسش
How can excess nitrogen or phosphorus cause eutrophication?
پاسخ
Nutrient enrichment drives algal growth; decomposition of the biomass consumes oxygen and can create hypoxic water.
کارت ۸۹۱
پرسش
Why can a persistent pollutant reach higher concentrations at higher trophic levels?
پاسخ
Predators consume contaminant stored in many prey, and the substance is not readily broken down or excreted.
کارت ۸۹۲
پرسش
How is trophic-transfer efficiency calculated?
پاسخ
Energy or biomass gained by the higher trophic level ÷ energy or biomass available at the lower level × 100%.
کارت ۸۹۳
پرسش
What is phenotypic variation?
پاسخ
Differences in observable traits among individuals of a population.
کارت ۸۹۴
پرسش
What is heritable variation?
پاسخ
Trait differences that can be transmitted genetically to offspring.
کارت ۸۹۵
پرسش
What is a selection pressure?
پاسخ
An environmental factor causing differences in survival or reproduction among phenotypes.
کارت ۸۹۶
پرسش
What is relative fitness?
پاسخ
An individual's reproductive success compared with others in the population.
کارت ۸۹۷
پرسش
Which term describes observable differences among individuals?
پاسخ
phenotypic variation
کارت ۸۹۸
پرسش
Which term describes genetically transmissible trait differences?
پاسخ
heritable variation
کارت ۸۹۹
پرسش
Which term describes an environmental factor producing differential reproductive success?
پاسخ
a selection pressure
کارت ۹۰۰
پرسش
Which term describes reproductive success relative to other individuals?
پاسخ
relative fitness
کارت ۹۰۱
پرسش
What is directional selection?
پاسخ
Selection favoring one extreme phenotype and shifting a population's trait distribution.
کارت ۹۰۲
پرسش
What is stabilizing selection?
پاسخ
Selection favoring intermediate phenotypes and acting against extremes.
کارت ۹۰۳
پرسش
What is disruptive selection?
پاسخ
Selection favoring both extreme phenotypes over intermediates.
کارت ۹۰۴
پرسش
What is sexual selection?
پاسخ
Selection arising from differences in mating success.
کارت ۹۰۵
پرسش
Which term describes selection shifting a trait toward one extreme?
پاسخ
directional selection
کارت ۹۰۶
پرسش
Which term describes selection favoring intermediate phenotypes?
پاسخ
stabilizing selection
کارت ۹۰۷
پرسش
Which term describes selection favoring both trait extremes?
پاسخ
disruptive selection
کارت ۹۰۸
پرسش
Which term describes selection caused by unequal mating success?
پاسخ
sexual selection
کارت ۹۰۹
پرسش
What conditions are required for natural selection?
پاسخ
Individuals vary, some variation is heritable, more offspring are produced than can reproduce, and variants differ in reproductive success.
کارت ۹۱۰
پرسش
How does natural selection produce antibiotic-resistant bacterial populations?
پاسخ
Existing resistant variants survive treatment and reproduce more than susceptible bacteria.
کارت ۹۱۱
پرسش
Does an antibiotic cause bacteria to mutate specifically toward resistance?
پاسخ
No. Resistance variants arise without regard to need; treatment selects among them.
کارت ۹۱۲
پرسش
Can an individual become genetically adapted through natural selection?
پاسخ
No. Selection acts on individuals, but adaptation is a population change across generations.
کارت ۹۱۳
پرسش
How does artificial selection differ from natural selection?
پاسخ
Humans choose breeding traits in artificial selection; environmental conditions determine differential reproduction in natural selection.
کارت ۹۱۴
پرسش
How does natural selection change a population?
پاسخ
Individuals with advantageous heritable variants leave more offspring, increasing those alleles over generations.
کارت ۹۱۵
پرسش
Why is fitness environment-dependent?
پاسخ
A trait that improves reproduction in one environment may be neutral or costly in another.
کارت ۹۱۶
پرسش
How does genetic drift differ from natural selection?
پاسخ
Drift changes allele frequencies by chance sampling; selection changes them through consistent fitness differences.
کارت ۹۱۷
پرسش
What is ecosystem stability?
پاسخ
The capacity of an ecosystem to maintain or recover its structure and functions despite disturbance.
کارت ۹۱۸
پرسش
What is an ecological tipping point?
پاسخ
A threshold beyond which feedbacks can drive a large and difficult-to-reverse ecosystem shift.
کارت ۹۱۹
پرسش
What is a mesocosm?
پاسخ
A controlled, simplified ecosystem used to investigate ecological processes under more realistic conditions than a small laboratory vessel.
کارت ۹۲۰
پرسش
What is a sustainable yield?
پاسخ
A harvest rate that can continue without causing long-term resource decline under prevailing conditions.
کارت ۹۲۱
پرسش
Which term describes the capacity of an ecosystem to persist or recover after disturbance?
پاسخ
ecosystem stability
کارت ۹۲۲
پرسش
Which term describes a threshold triggering a major hard-to-reverse ecosystem shift?
پاسخ
an ecological tipping point
کارت ۹۲۳
پرسش
Which term describes a controlled model ecosystem used for experiments?
پاسخ
a mesocosm
کارت ۹۲۴
پرسش
Which term describes a harvest rate that avoids long-term depletion?
پاسخ
a sustainable yield
کارت ۹۲۵
پرسش
What is eutrophication?
پاسخ
Nutrient enrichment of water that stimulates excess primary production and can lead to oxygen depletion.
کارت ۹۲۶
پرسش
What is biomagnification?
پاسخ
Increase in concentration of a persistent pollutant at successively higher trophic levels.
کارت ۹۲۷
پرسش
What is rewilding?
پاسخ
Ecosystem restoration that rebuilds natural processes, species interactions, and self-sustaining ecological function.
کارت ۹۲۸
پرسش
What features can make an ecosystem more stable?
پاسخ
Diverse functional roles, connected habitats, intact food webs, nutrient cycling, and balancing feedbacks can help the system resist or recover from disturbance.
کارت ۹۲۹
پرسش
Which term describes nutrient enrichment that can deplete oxygen in water?
پاسخ
eutrophication
کارت ۹۳۰
پرسش
Which term describes increasing pollutant concentration up a food chain?
پاسخ
biomagnification
کارت ۹۳۱
پرسش
Which term describes restoration focused on natural processes and self-sustaining ecosystems?
پاسخ
rewilding
کارت ۹۳۲
پرسش
How could extensive Amazon deforestation push the ecosystem toward a tipping point?
پاسخ
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.
کارت ۹۳۳
پرسش
What are a benefit and a limitation of using a mesocosm?
پاسخ
It allows controlled experiments with interacting organisms, but its simplified scale cannot reproduce every process or long-term influence in a natural ecosystem.
کارت ۹۳۴
پرسش
Why should a fishery harvest below an uncertain maximum sustainable yield?
پاسخ
Population estimates and recruitment vary, so a safety margin reduces the chance that error or a poor breeding year drives long-term decline.
کارت ۹۳۵
پرسش
How can intensive agriculture reduce ecosystem stability?
پاسخ
Habitat loss, low crop diversity, soil degradation, heavy water use, pesticides, and nutrient runoff can weaken food webs and ecosystem processes.
کارت ۹۳۶
پرسش
Why can microplastic pollution harm aquatic ecosystems?
پاسخ
Small persistent particles can be ingested, carry additives or other pollutants, damage feeding and tissues, and move through food webs.
کارت ۹۳۷
پرسش
How can rewilding improve ecosystem stability?
پاسخ
Restoring native species, habitat connections, and natural disturbance or grazing processes can rebuild feedbacks and allow the ecosystem to maintain itself with less intervention.
کارت ۹۳۸
پرسش
What is the greenhouse effect?
پاسخ
Warming caused when atmospheric gases absorb and re-emit outgoing infrared radiation.
کارت ۹۳۹
پرسش
What is a greenhouse gas?
پاسخ
An atmospheric gas that absorbs infrared radiation at wavelengths emitted by Earth.
کارت ۹۴۰
پرسش
What is carbon dioxide (CO₂)?
پاسخ
A long-lived greenhouse gas increased mainly by fossil-fuel combustion, cement production, and land-use change.
کارت ۹۴۱
پرسش
What is methane (CH₄)?
پاسخ
A potent greenhouse gas emitted by sources including fossil-fuel systems, livestock, rice cultivation, wetlands, and waste.
کارت ۹۴۲
پرسش
Which term describes warming from absorption and re-emission of infrared radiation?
پاسخ
the greenhouse effect
کارت ۹۴۳
پرسش
Which term describes an atmospheric infrared-absorbing gas?
پاسخ
a greenhouse gas
کارت ۹۴۴
پرسش
Which term describes the long-lived greenhouse gas strongly increased by fossil fuels?
پاسخ
carbon dioxide (CO₂)
کارت ۹۴۵
پرسش
Which term describes the potent short-lived greenhouse gas from biological and fossil sources?
پاسخ
methane (CH₄)
کارت ۹۴۶
پرسش
What is albedo?
پاسخ
The fraction of incoming radiation reflected by a surface.
کارت ۹۴۷
پرسش
What is a carbon sink?
پاسخ
A reservoir that absorbs more carbon than it releases over a specified period.
کارت ۹۴۸
پرسش
What is ocean acidification?
پاسخ
Decline in seawater pH caused mainly by absorption of human-emitted carbon dioxide.
کارت ۹۴۹
پرسش
What is climate change?
پاسخ
A persistent change in the statistical patterns of climate over decades or longer.
کارت ۹۵۰
پرسش
Which term describes surface reflectivity?
پاسخ
albedo
کارت ۹۵۱
پرسش
Which term describes a reservoir with net carbon uptake?
پاسخ
a carbon sink
کارت ۹۵۲
پرسش
Which term describes seawater pH decline from absorbed carbon dioxide?
پاسخ
ocean acidification
کارت ۹۵۳
پرسش
Which term describes long-term change in climate patterns?
پاسخ
climate change
کارت ۹۵۴
پرسش
What is the enhanced greenhouse effect?
پاسخ
Additional warming caused by human-driven increases in greenhouse-gas concentrations.
کارت ۹۵۵
پرسش
How do climate mitigation and climate adaptation differ?
پاسخ
Mitigation limits the magnitude of climate change; adaptation reduces harm from changes that occur.
کارت ۹۵۶
پرسش
How does increasing greenhouse-gas concentration alter Earth's energy balance?
پاسخ
Less outgoing infrared energy initially escapes to space, so the climate warms until energy balance is restored at a higher temperature.
کارت ۹۵۷
پرسش
How can melting ice amplify warming?
پاسخ
Less bright ice lowers albedo, so darker land or water absorbs more solar energy and causes further warming.
کارت ۹۵۸
پرسش
How can climate change alter species distributions?
پاسخ
Temperature, rainfall, seasons, sea level, and interactions shift, moving or shrinking areas with suitable conditions.
کارت ۹۵۹
پرسش
Why can ocean acidification harm calcifying organisms?
پاسخ
Carbonate chemistry changes, reducing availability of carbonate ions used to build calcium-carbonate structures.
کارت ۹۶۰
پرسش
How can ecosystem protection contribute to climate mitigation?
پاسخ
Protecting forests, wetlands, soils, and coastal habitats can avoid emissions and maintain or increase carbon storage.
۹۶۰ کارت
IB Biology SL Flashcards: Complete Course Review
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