ATI TEAS 7 Science Flashcards: A&P, Biology, Chemistry & Scientific Reasoning
Practice 446 original ATI TEAS 7 Science recall and mini-scenario cards across A&P, biology, chemistry, and scientific reasoning.
Despre acest pachet
Build the core Science knowledge and reasoning used for ATI TEAS 7 with 446 independently authored flashcards.
What this deck practices
- Structure or concept → function: body systems, cells, molecules, atoms, solutions, and experimental parts.
- Function, outcome, or evidence → concept: selective reverse recall when recognizing the name matters in practice.
- Cause or condition → effect: physiology, chemical changes, reaction conditions, inheritance, and experimental predictions.
- Process and order: circulation, ventilation, digestion, urine formation, gene expression, cell division, and scientific investigations.
- Application: short calculations, comparisons, data interpretations, and original mini-scenarios.
The deck does not mechanically reverse every fact. It excludes multiple-choice distractors, exhaustive anatomy lists, obscure chemical nomenclature, advanced pathophysiology, pharmacology, and nursing-school procedures because those mappings do not improve entry-level TEAS Science recall.
The sequence introduces prerequisites before dependent ideas: anatomical language before body systems, cells before genetics, atoms before reactions, and measurement before experimental design. Related forward and reverse variants are separated so one card does not immediately reveal another.
Coverage follows the four Science areas and relative emphasis in ATI's public ATI TEAS 7 content outline: Human Anatomy and Physiology, Biology, Chemistry, and Scientific Reasoning. The public outline defines scope only. Questions, answers, explanations, examples, and ordering were independently authored from common scientific knowledge checked against open educational and official public sources.
No exam question, mark scheme, paid ATI flashcard, test-bank item, or curriculum text was copied. This is an independent, unofficial educational deck by Flashcards Open Source App. ATI and TEAS are marks of Assessment Technologies Institute, L.L.C.; this deck is not affiliated with, endorsed by, or produced by ATI. See ATI's official exam details for current requirements.
Fișele din acest pachet
Fișa 1
Întrebare
What posture defines the standard anatomical position?
Răspuns
Standing upright, facing forward, with arms at the sides and palms forward. The feet point forward, giving anatomy a consistent reference position.
Fișa 2
Întrebare
In anatomical language, what does superior mean?
Răspuns
Toward the head or above another structure. Inferior means toward the feet or below.
Fișa 3
Întrebare
Which anatomical plane divides the body into left and right portions?
Răspuns
The sagittal plane. A midsagittal plane divides the body into equal left and right halves.
Fișa 4
Întrebare
Why does the body use feedback mechanisms?
Răspuns
To regulate internal conditions. Feedback compares a condition with a set range and triggers responses that adjust it.
Fișa 5
Întrebare
What is the order of structural organization from simplest to most complex?
Răspuns
Chemical, cellular, tissue, organ, organ system, organism. Each level builds on interactions at the preceding level.
Fișa 6
Întrebare
What does anterior mean in human anatomy?
Răspuns
Toward the front of the body. Posterior means toward the back.
Fișa 7
Întrebare
Which plane divides the body into upper and lower portions?
Răspuns
The transverse plane. It is also called the horizontal plane.
Fișa 8
Întrebare
What is homeostasis?
Răspuns
The maintenance of a relatively stable internal environment. It is dynamic rather than perfectly unchanging.
Fișa 9
Întrebare
Which major body cavity contains the brain and spinal cord?
Răspuns
The dorsal body cavity. Its cranial cavity holds the brain, and its vertebral cavity holds the spinal cord.
Fișa 10
Întrebare
What does medial mean in anatomical language?
Răspuns
Toward the body's midline. Lateral means farther from the midline.
Fișa 11
Întrebare
A rise in body temperature triggers sweating. What control pattern is this?
Răspuns
Negative feedback. The response opposes the original temperature change and moves the body toward its normal range.
Fișa 12
Întrebare
Which anatomical plane divides the body into front and back portions?
Răspuns
The frontal, or coronal, plane. It separates anterior from posterior portions.
Fișa 13
Întrebare
Which major body cavity contains the thoracic and abdominopelvic cavities?
Răspuns
The ventral body cavity. The diaphragm separates its thoracic and abdominopelvic portions.
Fișa 14
Întrebare
What does proximal mean when describing a limb?
Răspuns
Closer to the limb's point of attachment. Distal means farther from that point.
Fișa 15
Întrebare
How does positive feedback differ from negative feedback?
Răspuns
Positive feedback amplifies the initial change. Negative feedback opposes a change; positive feedback continues until a stopping event occurs.
Fișa 16
Întrebare
Which tissue type covers surfaces and lines body cavities?
Răspuns
Epithelial tissue. It also forms many glands and often serves protective, absorptive, or secretory roles.
Fișa 17
Întrebare
Which tissue type mainly supports, binds, and protects other tissues?
Răspuns
Connective tissue. Its cells are typically separated by an extracellular matrix.
Fișa 18
Întrebare
What shared property lets muscle tissue produce movement?
Răspuns
Contractility. Muscle cells shorten or develop tension in response to stimulation.
Fișa 19
Întrebare
Which tissue type rapidly communicates by electrical signals?
Răspuns
Nervous tissue. Neurons transmit signals, while supporting cells help maintain their environment.
Fișa 20
Întrebare
Why are tightly packed epithelial cells well suited for barriers?
Răspuns
They leave little space between cells. This continuous arrangement limits passage across a surface.
Fișa 21
Întrebare
What distinguishes connective tissue from epithelial tissue?
Răspuns
Connective tissue usually has abundant extracellular matrix. Epithelial cells are more tightly packed.
Fișa 22
Întrebare
What are the four basic human tissue types?
Răspuns
Epithelial, connective, muscle, and nervous tissue. Organs contain two or more tissue types working together.
Fișa 23
Întrebare
What makes a structure an organ rather than a tissue?
Răspuns
An organ combines multiple tissue types for a specific function. A tissue is a group of similar cells and matrix performing related work.
Fișa 24
Întrebare
What are the skeletal system's main functions?
Răspuns
Support, protection, movement, mineral storage, blood-cell production, and fat storage. Bones also provide levers for muscles.
Fișa 25
Întrebare
What belongs to the axial skeleton?
Răspuns
The skull, vertebral column, and thoracic cage. These structures form the body's central axis.
Fișa 26
Întrebare
How do compact and spongy bone differ?
Răspuns
Compact bone is dense; spongy bone has a lattice of trabeculae. Both are organized living bone tissue.
Fișa 27
Întrebare
What is a joint?
Răspuns
A place where two or more bones meet. Joint structure determines how much movement is possible.
Fișa 28
Întrebare
Which bone cell builds new bone matrix?
Răspuns
An osteoblast. Osteoclasts break down bone, while osteocytes maintain mature bone tissue.
Fișa 29
Întrebare
What belongs to the appendicular skeleton?
Răspuns
The limbs plus the shoulder and pelvic girdles. It attaches the limbs to the axial skeleton.
Fișa 30
Întrebare
What is the main role of red bone marrow?
Răspuns
Blood-cell production. This process is called hematopoiesis.
Fișa 31
Întrebare
Which joint class allows the greatest range of motion?
Răspuns
A synovial joint. A fluid-filled joint cavity reduces friction between articulating surfaces.
Fișa 32
Întrebare
Which bone cell breaks down bone matrix?
Răspuns
An osteoclast. Bone resorption helps remodeling and mineral balance.
Fișa 33
Întrebare
What does a ligament connect?
Răspuns
Bone to bone. A tendon connects muscle to bone.
Fișa 34
Întrebare
What is the shaft of a long bone called?
Răspuns
The diaphysis. The enlarged ends are the epiphyses.
Fișa 35
Întrebare
Why is bone important to blood-calcium balance?
Răspuns
Bone stores calcium and can release or absorb it during remodeling. Hormones regulate this exchange.
Fișa 36
Întrebare
What is stored mainly in yellow bone marrow?
Răspuns
Fat. It serves as an energy reserve.
Fișa 37
Întrebare
What does articular cartilage do at a synovial joint?
Răspuns
It reduces friction and absorbs shock. It covers the ends of articulating bones.
Fișa 38
Întrebare
Why must a broken bone receive a blood supply during healing?
Răspuns
Repairing cells need oxygen and nutrients. Restored blood vessels support fracture healing.
Fișa 39
Întrebare
What is bone remodeling?
Răspuns
Continuous removal and replacement of bone tissue. It repairs microdamage and helps bones adapt to stress.
Fișa 40
Întrebare
Which muscle tissue is usually under voluntary control?
Răspuns
Skeletal muscle. Most skeletal muscles move the skeleton, while some, such as facial muscles, insert into skin or other soft tissue.
Fișa 41
Întrebare
What is a sarcomere?
Răspuns
The basic contractile unit of striated muscle. It lies between two Z discs.
Fișa 42
Întrebare
What does a tendon connect?
Răspuns
Muscle to bone. It transmits muscle force to the skeleton.
Fișa 43
Întrebare
Which proteins slide past one another during muscle contraction?
Răspuns
Actin and myosin. Their interaction shortens sarcomeres without shortening the filaments themselves.
Fișa 44
Întrebare
Where is smooth muscle commonly found?
Răspuns
In the walls of hollow organs and blood vessels. Its contractions are generally involuntary.
Fișa 45
Întrebare
What ion exposes binding sites needed for skeletal muscle contraction?
Răspuns
Calcium. Its release inside the muscle fiber allows actin and myosin interaction.
Fișa 46
Întrebare
How do antagonistic muscle pairs move a joint?
Răspuns
One muscle contracts while the opposing muscle relaxes. Reversing their roles moves the joint in the opposite direction.
Fișa 47
Întrebare
Why does muscle contraction require ATP?
Răspuns
ATP powers cross-bridge cycling and ion pumps. It is also needed for myosin to detach from actin.
Fișa 48
Întrebare
Which muscle tissue makes up the heart wall?
Răspuns
Cardiac muscle. It is striated, involuntary, and connected for coordinated pumping.
Fișa 49
Întrebare
During a typical muscle contraction, which attachment moves more: origin or insertion?
Răspuns
The insertion. The origin is generally the more fixed attachment.
Fișa 50
Întrebare
Which type of neuron sends the signal that initiates skeletal-muscle contraction?
Răspuns
A somatic motor neuron. It releases acetylcholine at the neuromuscular junction, triggering an action potential in the muscle fiber.
Fișa 51
Întrebare
What is muscle tone?
Răspuns
Continuous low-level muscle tension. It helps maintain posture and readiness without producing a large movement.
Fișa 52
Întrebare
How does skeletal muscle help regulate body temperature?
Răspuns
Contraction releases heat. Shivering increases rapid contractions when the body is cold.
Fișa 53
Întrebare
What are the three muscle tissue types?
Răspuns
Skeletal, cardiac, and smooth muscle. They differ in location, structure, and control.
Fișa 54
Întrebare
What is a neuron's main function?
Răspuns
To receive, process, and transmit information. Neurons use electrical signals and chemical messengers.
Fișa 55
Întrebare
What structures make up the central nervous system?
Răspuns
The brain and spinal cord. They integrate information and coordinate responses.
Fișa 56
Întrebare
Which part of a neuron usually receives incoming signals?
Răspuns
The dendrites. The cell body integrates much of that input.
Fișa 57
Întrebare
What does the peripheral nervous system include?
Răspuns
Nerves and ganglia outside the brain and spinal cord. It links the central nervous system with the rest of the body.
Fișa 58
Întrebare
Which neuron structure carries an impulse away from the cell body?
Răspuns
The axon. Its terminals communicate with another cell.
Fișa 59
Întrebare
Which nervous-system division controls skeletal muscles voluntarily?
Răspuns
The somatic nervous system. It also carries sensory information from skin, muscles, and joints.
Fișa 60
Întrebare
What is a synapse?
Răspuns
A junction where one neuron communicates with another cell. Chemical synapses use neurotransmitters across a small gap.
Fișa 61
Întrebare
Which nervous-system division regulates organs and glands without conscious control?
Răspuns
The autonomic nervous system. It includes sympathetic and parasympathetic divisions.
Fișa 62
Întrebare
How does myelin affect nerve signaling?
Răspuns
It speeds impulse conduction along an axon. Myelin insulates segments of the axon.
Fișa 63
Întrebare
Which autonomic division prepares the body for acute activity?
Răspuns
The sympathetic division. It generally increases alertness and supports a fight-or-flight response.
Fișa 64
Întrebare
What is a reflex?
Răspuns
A rapid, predictable response to a stimulus. A reflex pathway can act before conscious awareness.
Fișa 65
Întrebare
Which autonomic division supports rest, digestion, and energy conservation?
Răspuns
The parasympathetic division. It generally promotes routine maintenance functions.
Fișa 66
Întrebare
Which brain region is most associated with conscious thought and voluntary movement?
Răspuns
The cerebrum. Its cortex also processes much sensory information.
Fișa 67
Întrebare
Which brain region fine-tunes balance and coordinated movement?
Răspuns
The cerebellum. It compares intended movement with sensory feedback.
Fișa 68
Întrebare
Which brain region controls vital automatic functions such as breathing and heart rate?
Răspuns
The brainstem. It also connects higher brain regions with the spinal cord.
Fișa 69
Întrebare
How do sensory and motor neurons differ?
Răspuns
Sensory neurons carry information toward the CNS; motor neurons carry commands away. Interneurons connect and process signals within the CNS.
Fișa 70
Întrebare
What does a sensory receptor do?
Răspuns
It converts a stimulus into a neural signal. Different receptors respond best to particular forms of energy or chemicals.
Fișa 71
Întrebare
What is a hormone?
Răspuns
A chemical messenger released into body fluids to affect target cells. A target responds only if it has the appropriate receptor.
Fișa 72
Întrebare
Why is the pituitary gland often called a master gland?
Răspuns
Several pituitary hormones regulate other endocrine glands. The hypothalamus controls much of pituitary activity.
Fișa 73
Întrebare
Why can one hormone affect some cells but not others?
Răspuns
Only target cells have the matching receptor. Receptor binding starts the cell's response.
Fișa 74
Întrebare
Which gland produces hormones that broadly increase metabolic activity?
Răspuns
The thyroid gland. Thyroid hormones influence energy use and development.
Fișa 75
Întrebare
What is insulin's main effect on blood glucose?
Răspuns
It lowers blood glucose. Insulin promotes glucose uptake and storage after a meal.
Fișa 76
Întrebare
Which glands release a hormone that raises blood calcium?
Răspuns
The parathyroid glands. Parathyroid hormone acts on bone, kidneys, and vitamin D pathways.
Fișa 77
Întrebare
Which adrenal region releases epinephrine during acute stress?
Răspuns
The adrenal medulla. Its hormones reinforce sympathetic nervous-system effects.
Fișa 78
Întrebare
Which organ has both endocrine and digestive functions?
Răspuns
The pancreas. Its islets release hormones, while other cells release digestive enzymes.
Fișa 79
Întrebare
What is glucagon's main effect on blood glucose?
Răspuns
It raises blood glucose. It promotes release of stored glucose during fasting.
Fișa 80
Întrebare
Rising thyroid hormone reduces its own upstream stimulation. What pattern is this?
Răspuns
Negative feedback. The final hormone limits further release along the control pathway.
Fișa 81
Întrebare
Which adrenal region produces steroid hormones such as cortisol and aldosterone?
Răspuns
The adrenal cortex. It surrounds the adrenal medulla.
Fișa 82
Întrebare
Which gland releases melatonin and helps regulate daily sleep timing?
Răspuns
The pineal gland. Light information influences its secretion pattern.
Fișa 83
Întrebare
Which hormone directly increases collecting-duct water permeability?
Răspuns
Antidiuretic hormone, or ADH. It makes collecting ducts more permeable to water, increasing water reabsorption and usually producing less, more concentrated urine.
Fișa 84
Întrebare
Which hormone strengthens uterine contractions during labor?
Răspuns
Oxytocin. This is a classic positive-feedback pathway that ends after delivery.
Fișa 85
Întrebare
How does endocrine signaling generally differ from nervous signaling?
Răspuns
It is usually slower to start and longer lasting. Hormones travel through body fluids, while neurons signal specific targets rapidly.
Fișa 86
Întrebare
What is plasma?
Răspuns
The liquid portion of blood. It carries cells, nutrients, hormones, proteins, wastes, and dissolved gases.
Fișa 87
Întrebare
Which side of the heart pumps blood to the lungs?
Răspuns
The right side. The right ventricle sends deoxygenated blood through the pulmonary trunk and arteries.
Fișa 88
Întrebare
What is the main function of red blood cells?
Răspuns
Transporting oxygen. Their hemoglobin also carries a smaller share of carbon dioxide.
Fișa 89
Întrebare
What defines an artery?
Răspuns
It carries blood away from the heart. Oxygen content does not define it; pulmonary arteries carry deoxygenated blood.
Fișa 90
Întrebare
What is the main function of white blood cells?
Răspuns
Body defense. Different white blood cells recognize, attack, or coordinate responses to threats.
Fișa 91
Întrebare
Which side of the heart pumps blood into systemic circulation?
Răspuns
The left side. The left ventricle sends oxygenated blood into the aorta.
Fișa 92
Întrebare
What is the main purpose of heart valves?
Răspuns
To keep blood moving in one direction. Pressure differences open and close them.
Fișa 93
Întrebare
What defines a vein?
Răspuns
It carries blood toward the heart. Many veins contain valves that limit backflow.
Fișa 94
Întrebare
What is the main role of platelets?
Răspuns
Helping stop bleeding. They form a platelet plug and support clotting reactions at a damaged vessel.
Fișa 95
Întrebare
Why are capillaries well suited for exchange?
Răspuns
Their walls are only one cell layer thick. Their small diameter and large total surface area support diffusion and filtration.
Fișa 96
Întrebare
After blood enters the right atrium, what chamber receives it next?
Răspuns
The right ventricle. Blood passes through the tricuspid valve before entering that chamber.
Fișa 97
Întrebare
What happens during ventricular systole?
Răspuns
The ventricles contract and eject blood. The right ventricle pumps to the lungs, and the left pumps to the body.
Fișa 98
Întrebare
What is pulmonary circulation?
Răspuns
Blood flow between the heart and lungs. It allows gas exchange and returns oxygenated blood to the left atrium.
Fișa 99
Întrebare
What normally sets the heart's rhythm?
Răspuns
The sinoatrial, or SA, node. Its spontaneous electrical activity initiates each heartbeat.
Fișa 100
Întrebare
What molecule in red blood cells binds oxygen?
Răspuns
Hemoglobin. Its iron-containing heme groups bind oxygen reversibly.
Fișa 101
Întrebare
What happens during ventricular diastole?
Răspuns
The ventricles relax and fill. Atrioventricular valves are open during most ventricular filling.
Fișa 102
Întrebare
What is systemic circulation?
Răspuns
Blood flow between the heart and the body's tissues. It delivers oxygen and nutrients and returns wastes.
Fișa 103
Întrebare
What does arterial blood pressure measure?
Răspuns
The force of blood against artery walls. It is commonly reported as systolic over diastolic pressure.
Fișa 104
Întrebare
What do coronary arteries supply?
Răspuns
The heart muscle itself. Blocked coronary blood flow can deprive myocardium of oxygen.
Fișa 105
Întrebare
Which major vessels return systemic blood to the right atrium?
Răspuns
The superior and inferior venae cavae. The superior vessel drains the upper body; the inferior drains the lower body.
Fișa 106
Întrebare
What is the respiratory system's primary gas-exchange function?
Răspuns
Bringing oxygen into the body and removing carbon dioxide. Ventilation moves air, while diffusion exchanges gases.
Fișa 107
Întrebare
What is the airflow sequence from the pharynx to the gas-exchange surfaces?
Răspuns
Pharynx, larynx, trachea, bronchi, bronchioles, alveoli. Each branch conducts air deeper into the lungs.
Fișa 108
Întrebare
Where does most gas exchange occur in the lungs?
Răspuns
Across the alveolar-capillary membrane. Thin walls and a large surface area shorten diffusion distance.
Fișa 109
Întrebare
What does the diaphragm do during quiet inhalation?
Răspuns
It contracts and moves downward. Thoracic volume rises, lung pressure falls, and air flows inward.
Fișa 110
Întrebare
Why does oxygen move from alveoli into pulmonary capillaries?
Răspuns
Its partial pressure is higher in alveolar air than in incoming blood. Oxygen diffuses down that gradient.
Fișa 111
Întrebare
What drives quiet exhalation?
Răspuns
Elastic recoil after inspiratory muscles relax. Thoracic volume falls and pressure pushes air outward.
Fișa 112
Întrebare
What is the pleura?
Răspuns
A double membrane surrounding each lung. A thin fluid layer reduces friction during breathing.
Fișa 113
Întrebare
How is most oxygen transported in blood?
Răspuns
Bound to hemoglobin in red blood cells. Only a small amount dissolves directly in plasma.
Fișa 114
Întrebare
Why does carbon dioxide move from pulmonary blood into alveoli?
Răspuns
Its partial pressure is higher in incoming blood than in alveolar air. It diffuses down that gradient for exhalation.
Fișa 115
Întrebare
What helps keep swallowed material out of the airway?
Răspuns
The epiglottis and coordinated swallowing reflexes. The laryngeal opening is protected as food passes.
Fișa 116
Întrebare
How does the conducting airway remove trapped particles?
Răspuns
Mucus traps them, and cilia move the mucus toward the throat. This is the mucociliary escalator.
Fișa 117
Întrebare
In what form is most carbon dioxide transported in blood?
Răspuns
As bicarbonate ions. Red blood cells help convert carbon dioxide and water into bicarbonate.
Fișa 118
Întrebare
Which blood change is a strong normal stimulus to increase breathing?
Răspuns
A rise in carbon dioxide and the associated fall in pH. Brainstem centers adjust ventilation in response.
Fișa 119
Întrebare
Why must alveoli receive both air and blood?
Răspuns
Gas exchange needs ventilation and perfusion. Air without blood flow, or blood without airflow, cannot exchange gases effectively.
Fișa 120
Întrebare
Why does ventilation increase during exercise?
Răspuns
Active tissues use more oxygen and produce more carbon dioxide. Faster, deeper breathing helps meet that demand.
Fișa 121
Întrebare
What are the digestive system's core functions?
Răspuns
Ingestion, digestion, absorption, and elimination. Movement and secretion support those processes.
Fișa 122
Întrebare
What is the alimentary-canal sequence after the mouth?
Răspuns
Pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus. Food passes through this continuous tube.
Fișa 123
Întrebare
What is mechanical digestion?
Răspuns
Physical breakdown and mixing of food without changing its molecules. Chewing and stomach churning are examples.
Fișa 124
Întrebare
What are two major functions of the stomach?
Răspuns
It stores and mixes food and begins substantial protein digestion. Acid denatures proteins, converts pepsinogen to pepsin, and provides the low pH pepsin needs.
Fișa 125
Întrebare
Where does most nutrient absorption occur?
Răspuns
The small intestine. Folds, villi, and microvilli create a large absorptive surface.
Fișa 126
Întrebare
Which nutrient does salivary amylase begin digesting in the mouth?
Răspuns
Carbohydrates, especially starch. Salivary amylase breaks starch into smaller carbohydrates.
Fișa 127
Întrebare
What is chemical digestion?
Răspuns
Enzymatic breakdown of large food molecules into absorbable units. Chemical bonds are changed during the process.
Fișa 128
Întrebare
What is peristalsis?
Răspuns
Wave-like smooth-muscle contractions that move material forward. It occurs throughout much of the digestive tract.
Fișa 129
Întrebare
What is a main function of the large intestine?
Răspuns
Absorbing water and electrolytes and forming feces. Resident microbes also process some undigested material.
Fișa 130
Întrebare
What digestive product does the liver make?
Răspuns
Bile. Bile salts help disperse dietary fat into smaller droplets.
Fișa 131
Întrebare
What does a digestive sphincter do?
Răspuns
It regulates movement between regions of the digestive tract. Circular muscle contracts to close a passage.
Fișa 132
Întrebare
What does the pancreas release into the small intestine?
Răspuns
Digestive enzymes and bicarbonate-rich fluid. Bicarbonate helps neutralize acidic material from the stomach.
Fișa 133
Întrebare
How do intestinal villi improve absorption?
Răspuns
They increase surface area. Each villus contains blood capillaries and a lymphatic lacteal for transported nutrients.
Fișa 134
Întrebare
What is the gallbladder's role?
Răspuns
It stores and concentrates bile. It releases bile into the small intestine when fatty food arrives.
Fișa 135
Întrebare
Which macronutrient's absorbed products usually enter intestinal lacteals before reaching the blood?
Răspuns
Most dietary lipids. Their absorbed products travel through lymph before entering the bloodstream.
Fișa 136
Întrebare
Which accessory organs help digestion without food passing through them?
Răspuns
The teeth, tongue, salivary glands, liver, gallbladder, and pancreas. Teeth and the tongue act mechanically; the other accessory organs add or store digestive secretions.
Fișa 137
Întrebare
What organs make up the urinary system?
Răspuns
The kidneys, ureters, urinary bladder, and urethra. Kidneys make urine; the remaining organs transport, store, and release it.
Fișa 138
Întrebare
What is a nephron?
Răspuns
The kidney's functional unit. It filters blood and adjusts the filtrate to form urine.
Fișa 139
Întrebare
Where does blood filtration begin in a nephron?
Răspuns
At the renal corpuscle. Pressure pushes water and small solutes from glomerular capillaries into the capsule.
Fișa 140
Întrebare
What moves urine from a kidney to the bladder?
Răspuns
A ureter. Smooth-muscle contractions propel urine along the tube.
Fișa 141
Întrebare
What is the urinary bladder's main role?
Răspuns
Temporary urine storage. Stretch receptors help trigger the urge to urinate as it fills.
Fișa 142
Întrebare
Which structure carries urine from the bladder out of the body?
Răspuns
The urethra. It is distinct from the ureters that enter the bladder.
Fișa 143
Întrebare
What is tubular reabsorption?
Răspuns
Movement of useful substances from nephron fluid back into blood. Water, glucose, and ions are common examples.
Fișa 144
Întrebare
What is the glomerulus?
Răspuns
A capillary tuft that filters blood in the renal corpuscle. Cells and most large proteins normally remain in circulation.
Fișa 145
Întrebare
How does more ADH change urine?
Răspuns
It makes urine more concentrated and lowers its volume. More water is reabsorbed from the collecting ducts.
Fișa 146
Întrebare
What path does filtrate follow after entering the glomerular capsule?
Răspuns
Proximal convoluted tubule → nephron loop → distal convoluted tubule → collecting duct. The collecting duct receives forming urine from multiple nephrons.
Fișa 147
Întrebare
What is tubular secretion?
Răspuns
Movement of selected substances from blood into nephron fluid. It helps eliminate wastes and regulate ions and pH.
Fișa 148
Întrebare
Besides removing waste, what does the urinary system regulate?
Răspuns
Water, electrolytes, acid-base balance, and blood volume. Kidney hormones also affect blood pressure and red-cell production.
Fișa 149
Întrebare
Why does dehydration usually reduce urine volume?
Răspuns
The body conserves water by increasing renal reabsorption. ADH is an important signal in this response.
Fișa 150
Întrebare
Why do the kidneys receive a large blood flow?
Răspuns
They must continuously filter plasma and regulate its composition. High flow supports waste removal and homeostasis.
Fișa 151
Întrebare
What is lymph?
Răspuns
Interstitial fluid that has entered lymphatic vessels. It eventually returns to the bloodstream.
Fișa 152
Întrebare
What is innate immunity?
Răspuns
Rapid, nonspecific defense present before a particular exposure. Barriers, inflammation, and several immune cells contribute.
Fișa 153
Întrebare
What is a major function of lymph nodes?
Răspuns
Filtering lymph and providing sites for immune-cell activation. Swelling can reflect an active immune response.
Fișa 154
Întrebare
What does the spleen filter?
Răspuns
Blood. It removes aged blood cells and supports immune responses to blood-borne antigens.
Fișa 155
Întrebare
What is a key function of B lymphocytes?
Răspuns
Producing antibody-secreting cells and memory cells. Antibodies bind specific antigens.
Fișa 156
Întrebare
What distinguishes adaptive immunity?
Răspuns
It targets specific antigens and develops memory. Later exposure can trigger a faster, stronger response.
Fișa 157
Întrebare
Which lymphatic organ is important for T-cell maturation?
Răspuns
The thymus. It is most active early in life.
Fișa 158
Întrebare
What is the body's first physical barrier against many pathogens?
Răspuns
Intact skin and mucous membranes. Their secretions and normal microbes add protection.
Fișa 159
Întrebare
What is a key function of T lymphocytes?
Răspuns
Coordinating immune responses or killing infected cells. Different T-cell types perform different roles.
Fișa 160
Întrebare
What does an antibody bind?
Răspuns
A specific antigen. Binding can neutralize a target or mark it for other immune defenses.
Fișa 161
Întrebare
What is the purpose of inflammation after tissue injury?
Răspuns
To contain damage, recruit defenses, and begin repair. Redness, heat, swelling, and pain can accompany it.
Fișa 162
Întrebare
Why is a second adaptive response often faster than the first?
Răspuns
Memory lymphocytes remain after the first exposure. They respond quickly when the same antigen appears again.
Fișa 163
Întrebare
What does a phagocyte do?
Răspuns
It engulfs particles, microbes, or debris. Neutrophils and macrophages are important examples.
Fișa 164
Întrebare
How does vaccination support adaptive immunity?
Răspuns
It safely exposes the immune system to antigen information. This promotes memory without requiring the full disease.
Fișa 165
Întrebare
Why is lymphatic fluid return important?
Răspuns
It prevents excess interstitial fluid from accumulating. Lymphatic vessels return fluid and leaked proteins to blood.
Fișa 166
Întrebare
What structures belong to the integumentary system?
Răspuns
Skin, hair, nails, sweat glands, and sebaceous glands. Together they form the body's outer covering.
Fișa 167
Întrebare
What is the epidermis?
Răspuns
The outer epithelial layer of skin. It is avascular and contains protective keratinized cells.
Fișa 168
Întrebare
How does sweating cool the body?
Răspuns
Evaporation removes heat from the skin. Skin blood-flow changes also help regulate heat loss.
Fișa 169
Întrebare
What is a major role of melanin in skin?
Răspuns
Absorbing some ultraviolet radiation. It also contributes to skin and hair color.
Fișa 170
Întrebare
How does skin contribute to sensation?
Răspuns
Sensory receptors detect touch, pressure, pain, and temperature. Nerves carry that information to the CNS.
Fișa 171
Întrebare
What is the dermis?
Răspuns
The connective-tissue layer beneath the epidermis. It contains vessels, nerves, glands, and hair follicles.
Fișa 172
Întrebare
How does skin support vitamin D production?
Răspuns
Ultraviolet light starts conversion of a skin molecule into a vitamin D precursor. The liver and kidneys complete activation.
Fișa 173
Întrebare
Why does a deep skin wound bleed but a shallow epidermal scrape may not?
Răspuns
Blood vessels are in the dermis, not the epidermis. A wound must reach vascular tissue to damage them.
Fișa 174
Întrebare
What is a gamete?
Răspuns
A haploid reproductive cell. Human sperm and oocytes each carry 23 chromosomes.
Fișa 175
Întrebare
What are the testes' two main reproductive functions?
Răspuns
Producing sperm and secreting testosterone. Sperm develop in seminiferous tubules.
Fișa 176
Întrebare
What tube carries sperm from the epididymis toward the ejaculatory duct?
Răspuns
The ductus, or vas, deferens. Smooth muscle propels sperm during ejaculation.
Fișa 177
Întrebare
What is ovulation?
Răspuns
Release of a secondary oocyte from an ovary. A surge in luteinizing hormone helps trigger it.
Fișa 178
Întrebare
Where does fertilization usually occur?
Răspuns
In a uterine tube. The early embryo then travels toward the uterus.
Fișa 179
Întrebare
What are the ovaries' two main reproductive functions?
Răspuns
Producing oocytes and secreting sex hormones. Estrogen and progesterone help regulate the reproductive cycle.
Fișa 180
Întrebare
What is the uterus' main reproductive role?
Răspuns
Supporting implantation and development of an embryo and fetus. Its muscular wall also contracts during birth.
Fișa 181
Întrebare
What causes menstruation when pregnancy does not occur?
Răspuns
Falling ovarian hormones allow the uterine lining to shed. A new cycle then begins.
Fișa 182
Întrebare
How does a sperm cell's structure support its function?
Răspuns
Its flagellum provides movement, and its head carries DNA plus enzymes used during fertilization. Mitochondria supply energy in the midpiece.
Fișa 183
Întrebare
What is the placenta's exchange role?
Răspuns
It allows gases, nutrients, and wastes to move between maternal and fetal circulations. Their blood normally does not mix directly.
Fișa 184
Întrebare
Why is meiosis necessary for sexual reproduction?
Răspuns
It halves chromosome number in gametes. Fertilization then restores the diploid number.
Fișa 185
Întrebare
How do sex hormones regulate reproductive control pathways?
Răspuns
They usually feed back on the hypothalamus and pituitary. This adjusts release of hormones that act on the gonads.
Fișa 186
Întrebare
What does cell theory state?
Răspuns
Living things are made of cells, cells are the basic units of life, and cells come from existing cells. These ideas link organism structure with cell division.
Fișa 187
Întrebare
What is the defining structural feature of a prokaryotic cell?
Răspuns
It lacks a membrane-bound nucleus. Its DNA occupies a nucleoid region.
Fișa 188
Întrebare
What is the cell membrane's main role?
Răspuns
Regulating movement between the cell and its environment. Its phospholipid bilayer is selectively permeable.
Fișa 189
Întrebare
What is the nucleus' main role?
Răspuns
Storing most of a eukaryotic cell's DNA. Nuclear pores regulate exchange with the cytoplasm.
Fișa 190
Întrebare
Where are proteins assembled?
Răspuns
At ribosomes. Ribosomes may float in cytosol or attach to rough endoplasmic reticulum.
Fișa 191
Întrebare
What distinguishes a eukaryotic cell from a prokaryotic cell?
Răspuns
A eukaryotic cell has a membrane-bound nucleus and other membrane-bound organelles. Animals, plants, fungi, and protists are eukaryotes.
Fișa 192
Întrebare
What is a mitochondrion's main function?
Răspuns
Producing most cellular ATP through aerobic respiration. Its inner membrane provides a large reaction surface.
Fișa 193
Întrebare
What does rough endoplasmic reticulum mainly produce?
Răspuns
Proteins for secretion, membranes, or organelles. Ribosomes on its surface make the proteins.
Fișa 194
Întrebare
Which organelle carries out photosynthesis in plants and algae?
Răspuns
The chloroplast. It converts light energy into chemical energy stored in organic molecules.
Fișa 195
Întrebare
What does the Golgi apparatus do?
Răspuns
It modifies, sorts, and packages cell products. Vesicles carry those products to their destinations.
Fișa 196
Întrebare
What is a lysosome's role?
Răspuns
Digesting worn cell parts and engulfed material. Its enzymes work best in an acidic interior.
Fișa 197
Întrebare
What are major functions of smooth endoplasmic reticulum?
Răspuns
Lipid synthesis, detoxification, and calcium storage. Its membrane lacks attached ribosomes.
Fișa 198
Întrebare
What does the cytoskeleton provide?
Răspuns
Cell shape, internal organization, movement, and transport tracks. It is built from protein filaments.
Fișa 199
Întrebare
What is diffusion?
Răspuns
Net movement from higher to lower concentration. It is passive and continues until dynamic equilibrium is reached.
Fișa 200
Întrebare
What happens to an animal cell in a strongly hypotonic solution?
Răspuns
Water enters and the cell swells. Without a cell wall, it may burst.
Fișa 201
Întrebare
What happens during interphase?
Răspuns
The cell grows, performs normal functions, and copies its DNA. Interphase precedes mitotic division.
Fișa 202
Întrebare
What is the result of mitosis followed by cytokinesis?
Răspuns
Two genetically similar daughter cells. Chromosome number is normally preserved.
Fișa 203
Întrebare
What is osmosis?
Răspuns
Diffusion of water across a selectively permeable membrane. Water moves toward the side with more nonpenetrating solute.
Fișa 204
Întrebare
What happens to an animal cell in a hypertonic solution?
Răspuns
Water leaves and the cell shrinks. The external solution has a higher effective solute concentration.
Fișa 205
Întrebare
Why are cells generally small?
Răspuns
A high surface-area-to-volume ratio supports efficient exchange. Volume grows faster than surface area as a cell enlarges.
Fișa 206
Întrebare
What is cytokinesis?
Răspuns
Division of the cytoplasm. It separates one cell into two after nuclear division.
Fișa 207
Întrebare
How does active transport differ from passive transport?
Răspuns
It uses energy to move substances against a gradient. Passive transport moves down a gradient without direct energy input.
Fișa 208
Întrebare
What happens to an animal cell in an isotonic solution?
Răspuns
There is no net water movement. Water still crosses in both directions at equal rates.
Fișa 209
Întrebare
Which structures are typical of plant cells but not animal cells?
Răspuns
A cellulose cell wall, chloroplasts, and a large central vacuole. Both cell types have membranes, nuclei, and mitochondria.
Fișa 210
Întrebare
How do cells contribute to a multicellular organism's organization?
Răspuns
Specialized cells form tissues, tissues form organs, and organs form systems. Division of labor supports complex functions.
Fișa 211
Întrebare
What is DNA's primary biological role?
Răspuns
Storing hereditary information. Its nucleotide sequence contains instructions used to build functional RNA and proteins.
Fișa 212
Întrebare
What are the three parts of a DNA nucleotide?
Răspuns
A deoxyribose sugar, a phosphate group, and a nitrogenous base. Nucleotides link to form each strand.
Fișa 213
Întrebare
Which bases pair in double-stranded DNA?
Răspuns
Adenine with thymine, and cytosine with guanine. Hydrogen bonds hold complementary strands together.
Fișa 214
Întrebare
How does RNA differ from DNA?
Răspuns
RNA usually has ribose, uses uracil instead of thymine, and is usually single-stranded. Several RNA types help express genes.
Fișa 215
Întrebare
What is a gene?
Răspuns
A DNA sequence that contributes to a functional product. The product may be a protein or a functional RNA.
Fișa 216
Întrebare
What is a chromosome?
Răspuns
A long DNA molecule packaged with proteins. It contains many genes and other sequences.
Fișa 217
Întrebare
What is DNA replication?
Răspuns
Copying DNA before cell division. Each new DNA molecule contains one old strand and one newly made strand.
Fișa 218
Întrebare
What is the usual flow of information from a protein-coding gene?
Răspuns
DNA to RNA to protein. Transcription makes RNA; translation builds the polypeptide.
Fișa 219
Întrebare
What happens during transcription?
Răspuns
RNA is synthesized from a DNA template. For a protein-coding gene, that RNA functions as or is processed into messenger RNA.
Fișa 220
Întrebare
What does messenger RNA carry?
Răspuns
A copy of coding information from DNA to a ribosome. Its codons specify the amino-acid sequence.
Fișa 221
Întrebare
What is a codon?
Răspuns
A three-nucleotide sequence in mRNA. Most codons specify an amino acid; some signal start or stop.
Fișa 222
Întrebare
What is the usual role of the AUG codon?
Răspuns
It starts translation and specifies methionine. The ribosome uses it to establish the reading frame.
Fișa 223
Întrebare
What happens during translation?
Răspuns
A ribosome reads mRNA and joins amino acids into a polypeptide. Transfer RNAs match codons with amino acids.
446 de fișe
ATI TEAS 7 Science Flashcards: A&P, Biology, Chemistry & Scientific Reasoning
Studiază gratuit acest pachetNibomo se deschide ca să poți începe să studiezi.
Fișa 224
Întrebare
What is transfer RNA's role in protein synthesis?
Răspuns
It carries an amino acid and matches its anticodon to an mRNA codon. This places the correct amino acid in sequence.
Fișa 225
Întrebare
What is an anticodon?
Răspuns
A three-base sequence on tRNA complementary to an mRNA codon. Pairing helps decode the message.
Fișa 226
Întrebare
What is a mutation?
Răspuns
A change in a DNA sequence. Its effect may be harmful, neutral, or beneficial depending on location and context.
Fișa 227
Întrebare
Why can a one-base insertion in a coding sequence have a large effect?
Răspuns
It can shift the reading frame. Every downstream codon may change until a stop signal appears.
Fișa 228
Întrebare
Why can changing one amino acid alter a protein's function?
Răspuns
Amino-acid sequence helps determine folding and shape. Shape controls many protein interactions.
Fișa 229
Întrebare
What is ribosomal RNA's role in protein synthesis?
Răspuns
It forms the structural and catalytic core of ribosomes. Ribosomal RNA helps align translation components and catalyzes peptide-bond formation.
Fișa 230
Întrebare
Why can different cell types contain the same DNA but perform different jobs?
Răspuns
They express different sets of genes. Different proteins give cells different structures and functions.
Fișa 231
Întrebare
Which mutation can be passed to offspring?
Răspuns
A mutation present in a gamete-forming lineage. A mutation limited to ordinary body cells is not inherited through reproduction.
Fișa 232
Întrebare
What is an allele?
Răspuns
An alternative version of a gene. Diploid individuals usually carry two alleles for each autosomal gene.
Fișa 233
Întrebare
What is genotype?
Răspuns
An organism's allele combination for a gene or set of genes. Genotype contributes to phenotype.
Fișa 234
Întrebare
What does homozygous mean?
Răspuns
Having two identical alleles for a gene. Examples include AA and aa.
Fișa 235
Întrebare
What makes an allele dominant in a simple Mendelian trait?
Răspuns
One copy is enough for its phenotype to appear in a heterozygote. Dominant does not mean common or beneficial.
Fișa 236
Întrebare
What does Mendel's law of segregation describe?
Răspuns
The two alleles for a gene separate during gamete formation. Each gamete receives one allele.
Fișa 237
Întrebare
What is phenotype?
Răspuns
An observable trait or characteristic. It can reflect genotype, environment, and their interaction.
Fișa 238
Întrebare
What does heterozygous mean?
Răspuns
Having two different alleles for a gene. An example is Aa.
Fișa 239
Întrebare
When does a recessive phenotype usually appear in a simple autosomal trait?
Răspuns
When both alleles are recessive. A heterozygote carries the allele without showing that phenotype.
Fișa 240
Întrebare
When does independent assortment apply most clearly?
Răspuns
When genes are on different chromosomes or far apart on the same chromosome. Their allele pairs enter gametes independently.
Fișa 241
Întrebare
What does a Punnett square predict?
Răspuns
Expected offspring genotype probabilities from specified parental gametes. It does not guarantee outcomes in a small family.
Fișa 242
Întrebare
For Aa × Aa, what is the chance of an aa offspring?
Răspuns
One fourth, or 25%. The genotype ratio is expected to be 1 AA : 2 Aa : 1 aa.
Fișa 243
Întrebare
For Aa × Aa with complete dominance, what phenotypic ratio is expected?
Răspuns
Three dominant-phenotype offspring to one recessive-phenotype offspring. This is a probability across many offspring.
Fișa 244
Întrebare
How can a test cross reveal the genotype behind a dominant phenotype?
Răspuns
Cross the individual with a homozygous recessive partner. Recessive offspring show that the unknown parent carried a recessive allele.
Fișa 245
Întrebare
What happens in incomplete dominance?
Răspuns
A heterozygote has an intermediate phenotype. Neither allele fully masks the other.
Fișa 246
Întrebare
How is the probability of two independent genetic events both occurring found?
Răspuns
Multiply their individual probabilities. This is the product rule.
Fișa 247
Întrebare
What does a pedigree show?
Răspuns
How a trait appears across generations of a family. Its pattern can suggest a mode of inheritance.
Fișa 248
Întrebare
Why can two parents have offspring ratios that differ from a Punnett-square expectation?
Răspuns
Each fertilization is a chance event. Expected ratios become more apparent with larger numbers of offspring.
Fișa 249
Întrebare
What happens in codominance?
Răspuns
Both alleles are distinctly expressed in a heterozygote. The AB blood type is a common example.
Fișa 250
Întrebare
What are major roles of carbohydrates?
Răspuns
Providing quick energy, storing energy, and forming some structures. Monosaccharides are their basic building blocks.
Fișa 251
Întrebare
What is a monomer?
Răspuns
A small building block that can join with others to form a larger molecule. Glucose, amino acids, and nucleotides are examples in different classes.
Fișa 252
Întrebare
What happens in a dehydration-synthesis reaction?
Răspuns
Monomers join while water is removed. The reaction builds a larger biological molecule.
Fișa 253
Întrebare
What does an enzyme do?
Răspuns
It lowers activation energy and speeds a reaction without being consumed. Its shape helps it bind specific substrates.
Fișa 254
Întrebare
What are major roles of lipids?
Răspuns
Long-term energy storage, membranes, insulation, and signaling. Lipids are mostly nonpolar and do not mix well with water.
Fișa 255
Întrebare
What does it mean for a protein to denature?
Răspuns
Its normal shape is disrupted. Heat, extreme pH, or chemicals can reduce its function.
Fișa 256
Întrebare
What happens during hydrolysis?
Răspuns
Water is used to split a larger molecule into smaller units. Digestion often uses hydrolysis reactions.
Fișa 257
Întrebare
Why do phospholipids form bilayers in water?
Răspuns
Their hydrophilic heads interact with water while hydrophobic tails turn inward. This arrangement forms cell-membrane structure.
Fișa 258
Întrebare
What are proteins built from?
Răspuns
Amino acids linked by peptide bonds. Their folded shapes support enzymes, transport, signaling, structure, and movement.
Fișa 259
Întrebare
How do starch and glycogen compare?
Răspuns
Both store glucose; plants use starch and animals use glycogen. Their branching patterns differ.
Fișa 260
Întrebare
How do saturated and unsaturated fatty acids differ?
Răspuns
Saturated fatty acids lack carbon-carbon double bonds; unsaturated ones have one or more. Double bonds often introduce bends.
Fișa 261
Întrebare
What immediate energy-carrying molecule powers many cell processes?
Răspuns
ATP. Energy released from nutrients can be transferred into ATP's phosphate bonds.
Fișa 262
Întrebare
What are nucleic acids built from?
Răspuns
Nucleotides. DNA stores hereditary information, while RNA performs several roles in gene expression.
Fișa 263
Întrebare
Which elements are common in all four major biological macromolecule classes?
Răspuns
Carbon, hydrogen, and oxygen. Nitrogen and phosphorus occur prominently in some classes.
Fișa 264
Întrebare
Why is three-dimensional shape important for macromolecules?
Răspuns
Shape determines many interactions and functions. A changed shape can prevent a molecule from binding its target.
Fișa 265
Întrebare
What are triglycerides built from?
Răspuns
One glycerol molecule and three fatty acids. They join through ester bonds to form a common energy-storage lipid.
Fișa 266
Întrebare
What is a pathogen?
Răspuns
An agent capable of causing disease. Not every microorganism is pathogenic.
Fișa 267
Întrebare
What type of cell is a bacterium?
Răspuns
A prokaryotic cell. Bacteria usually reproduce by binary fission.
Fișa 268
Întrebare
What cell type do fungi have?
Răspuns
Eukaryotic cells. Some fungi are unicellular yeasts, while others form multicellular filaments.
Fișa 269
Întrebare
What does disease transmission describe?
Răspuns
How an infectious agent moves to a susceptible host. Routes include contact, droplets, airborne spread, food, water, and vectors.
Fișa 270
Întrebare
What is a biological vector?
Răspuns
An organism that becomes infected with a pathogen and transmits it between hosts. The pathogen survives or reproduces inside the vector, unlike transport by a mechanical carrier.
Fișa 271
Întrebare
Why are viruses dependent on host cells?
Răspuns
They lack the complete machinery for reproduction and metabolism. They use host components to make new virus particles.
Fișa 272
Întrebare
What is a protist?
Răspuns
A diverse eukaryote that is not classified as an animal, plant, or fungus. Some protists cause disease, while many do not.
Fișa 273
Întrebare
Why do antibiotics not treat viral infections?
Răspuns
They target bacterial structures or processes that viruses lack. Antiviral drugs use different targets.
Fișa 274
Întrebare
How can normal microbiota protect a host?
Răspuns
They occupy space and use resources that pathogens might otherwise exploit. Some also support digestion or immune development.
Fișa 275
Întrebare
How does sterilization differ from disinfection?
Răspuns
Sterilization destroys or removes all microbial life, including resistant forms; disinfection reduces pathogens on objects. The required method depends on use.
Fișa 276
Întrebare
How do infection and disease differ?
Răspuns
Infection means an agent is established in a host; disease means normal function is impaired and signs or symptoms occur. Infection may be asymptomatic.
Fișa 277
Întrebare
How can breaking a transmission route reduce infectious disease?
Răspuns
It interrupts the chain connecting a source with a susceptible host. Hand hygiene, clean water, ventilation, and vector control target different links.
Fișa 278
Întrebare
What is an atom?
Răspuns
The smallest unit of an element that retains that element's chemical identity. Atoms contain a nucleus surrounded by electrons.
Fișa 279
Întrebare
What charge and location does an electron have?
Răspuns
Negative charge in the electron cloud around the nucleus. Electrons drive most chemical bonding.
Fișa 280
Întrebare
Why are valence electrons important?
Răspuns
They participate most directly in bonding and reactions. Their arrangement helps predict chemical behavior.
Fișa 281
Întrebare
What do elements in the same periodic-table group often share?
Răspuns
Similar valence-electron patterns and chemical properties. A group is a vertical column.
Fișa 282
Întrebare
What is an ion?
Răspuns
An atom or group of atoms with a net electric charge. Its total numbers of protons and electrons are unequal.
Fișa 283
Întrebare
What charge and location does a proton have?
Răspuns
Positive charge in the nucleus. The number of protons determines the element.
Fișa 284
Întrebare
What does an element's atomic number equal?
Răspuns
Its number of protons. A neutral atom has the same number of electrons.
Fișa 285
Întrebare
How does a neutral atom form a cation?
Răspuns
By losing one or more electrons. It has more protons than electrons and a positive charge.
Fișa 286
Întrebare
An atom has 8 protons. How many electrons does it have if it is neutral?
Răspuns
Eight electrons. Neutral atoms have equal positive and negative charges.
Fișa 287
Întrebare
What charge and location does a neutron have?
Răspuns
No electric charge, in the nucleus. Neutron number can vary among isotopes of an element.
Fișa 288
Întrebare
What does mass number equal?
Răspuns
Protons plus neutrons in one atom. It is a whole number for a specific isotope.
Fișa 289
Întrebare
How does a neutral atom form an anion?
Răspuns
By gaining one or more electrons. It has more electrons than protons and a negative charge.
Fișa 290
Întrebare
What does a period represent on the periodic table?
Răspuns
A horizontal row. Moving across a period changes proton number one element at a time.
Fișa 291
Întrebare
What are isotopes?
Răspuns
Atoms of the same element with different numbers of neutrons. They have the same atomic number but different mass numbers.
Fișa 292
Întrebare
What is matter?
Răspuns
Anything that has mass and occupies space. Solids, liquids, gases, and plasma are forms of matter.
Fișa 293
Întrebare
What distinguishes a solid from a liquid or gas?
Răspuns
A solid has a definite shape and volume. Its particles vibrate around relatively fixed positions.
Fișa 294
Întrebare
What is a physical change?
Răspuns
A change in form or state without changing chemical identity. Melting and cutting are examples.
Fișa 295
Întrebare
What is a physical property?
Răspuns
A characteristic observed without changing a substance's identity. Density, color, and melting point are examples.
Fișa 296
Întrebare
How does an element differ from a compound?
Răspuns
An element contains one kind of atom; a compound contains elements chemically combined in fixed proportions. Chemical methods can separate a compound into simpler substances.
Fișa 297
Întrebare
What distinguishes a liquid?
Răspuns
It has a definite volume but takes the shape of its container. Its particles remain close while moving past one another.
Fișa 298
Întrebare
What is a chemical change?
Răspuns
A process that forms one or more substances with new chemical identities. Bond rearrangement occurs.
Fișa 299
Întrebare
What is a chemical property?
Răspuns
A substance's ability to undergo a particular chemical change. Flammability and reactivity with acid are examples.
Fișa 300
Întrebare
Which phase changes connect solids and liquids?
Răspuns
Melting changes a solid to a liquid; freezing changes a liquid to a solid. These are opposite physical changes.
Fișa 301
Întrebare
How does a pure substance differ from a mixture?
Răspuns
A pure substance has a fixed composition and is an element or compound; a mixture has variable composition and physically combined components. Mixture components retain their identities.
Fișa 302
Întrebare
What distinguishes a gas?
Răspuns
It has neither a definite shape nor a definite volume. It expands to fill its container.
Fișa 303
Întrebare
What is the formula for density?
Răspuns
Density = mass ÷ volume. Density is an intensive property.
Fișa 304
Întrebare
Which phase changes connect liquids and gases?
Răspuns
Vaporization changes a liquid to a gas; condensation changes a gas to a liquid. Evaporation is vaporization at a liquid's surface.
Fișa 305
Întrebare
What is a mixture?
Răspuns
Two or more substances physically combined in variable proportions. Its components retain their chemical identities.
Fișa 306
Întrebare
How do intensive and extensive properties differ?
Răspuns
Intensive properties do not depend on sample amount; extensive properties do. Density and temperature are intensive, while mass and volume are extensive.
Fișa 307
Întrebare
A 20 g sample occupies 5 mL. What is its density?
Răspuns
4 g/mL. Divide 20 g by 5 mL.
Fișa 308
Întrebare
Which phase changes connect solids and gases directly?
Răspuns
Sublimation changes a solid to a gas; deposition changes a gas to a solid. Neither transition passes through the liquid state.
Fișa 309
Întrebare
How do homogeneous and heterogeneous mixtures differ?
Răspuns
A homogeneous mixture is uniform throughout; a heterogeneous mixture is not. A solution is homogeneous.
Fișa 310
Întrebare
Where are reactants and products written in a chemical equation?
Răspuns
Reactants are on the left; products are on the right. The arrow shows the direction represented.
Fișa 311
Întrebare
Why must a chemical equation be balanced?
Răspuns
Atoms are conserved in ordinary chemical reactions. Each element must have the same atom count on both sides.
Fișa 312
Întrebare
What does a coefficient in a chemical equation change?
Răspuns
The number of whole particles or moles represented. It multiplies every atom in the following formula.
Fișa 313
Întrebare
Why should subscripts not be changed when balancing an equation?
Răspuns
Changing a subscript changes the substance's identity. Balancing changes coefficients only.
Fișa 314
Întrebare
What coefficients balance H₂ + O₂ → H₂O?
Răspuns
2, 1, 2: 2H₂ + O₂ → 2H₂O. Both sides then contain four hydrogen atoms and two oxygen atoms.
Fișa 315
Întrebare
What pattern defines a synthesis reaction?
Răspuns
Two or more reactants form a more complex product. A general pattern is A + B → AB.
Fișa 316
Întrebare
What are typical products when a hydrocarbon burns completely in oxygen?
Răspuns
Carbon dioxide and water. Incomplete combustion can produce carbon monoxide or carbon.
Fișa 317
Întrebare
What is the net ionic equation for a typical strong acid–strong base neutralization?
Răspuns
H⁺(aq) + OH⁻(aq) → H₂O(l). The remaining ions are spectators and do not appear in the net ionic equation.
Fișa 318
Întrebare
What is a precipitate?
Răspuns
An insoluble solid that forms from substances in solution. Its appearance can signal a chemical reaction.
Fișa 319
Întrebare
What pattern defines a decomposition reaction?
Răspuns
One compound breaks into simpler products. A general pattern is AB → A + B.
Fișa 320
Întrebare
What is an exothermic reaction?
Răspuns
A reaction that releases heat to the surroundings. The surroundings often warm.
Fișa 321
Întrebare
What occurs in an oxidation-reduction reaction?
Răspuns
Electrons transfer or atoms change oxidation state. Oxidation is electron loss; reduction is electron gain.
Fișa 322
Întrebare
What is activation energy?
Răspuns
The minimum energy barrier reactants must overcome to react. Catalysts lower this barrier.
Fișa 323
Întrebare
Which observations can provide evidence of a chemical reaction?
Răspuns
Gas formation, a precipitate, sustained color change, light, or temperature change. No single sign proves a reaction without context.
Fișa 324
Întrebare
What is an endothermic reaction?
Răspuns
A reaction that absorbs heat from the surroundings. The surroundings may cool.
Fișa 325
Întrebare
Why does raising temperature usually speed a reaction?
Răspuns
Particles collide more often and with greater energy. More collisions overcome activation energy.
Fișa 326
Întrebare
Why can higher reactant concentration increase reaction rate?
Răspuns
More reactant particles occupy a given volume. This raises collision frequency.
Fișa 327
Întrebare
Why does powdered solid often react faster than one large piece?
Răspuns
Powder exposes more surface area. More particles are available for collisions.
Fișa 328
Întrebare
How does a catalyst speed a reaction?
Răspuns
It provides a pathway with lower activation energy. The catalyst is regenerated rather than consumed overall.
Fișa 329
Întrebare
How can increasing pressure affect a reaction between gases?
Răspuns
It can increase rate by bringing gas particles closer together. Collision frequency rises when volume falls.
Fișa 330
Întrebare
What does a reaction inhibitor do?
Răspuns
It slows a reaction. It may block a pathway, interfere with a catalyst, or remove reactive intermediates.
Fișa 331
Întrebare
Why can very high temperature slow an enzyme-catalyzed reaction?
Răspuns
The enzyme can denature and lose its active shape. Moderate warming helps only within the enzyme's stable range.
Fișa 332
Întrebare
What is dynamic equilibrium?
Răspuns
Forward and reverse reactions continue at equal rates. Concentrations remain constant even though particles still react.
Fișa 333
Întrebare
Does a catalyst change the final equilibrium amounts?
Răspuns
No. It speeds forward and reverse reactions, so equilibrium is reached sooner without changing its position.
Fișa 334
Întrebare
At equilibrium, what usually happens when the concentration of a dissolved or gaseous reactant increases?
Răspuns
The system shifts toward consuming some added reactant. It forms more product until a new equilibrium is reached.
Fișa 335
Întrebare
What is a solution?
Răspuns
A homogeneous mixture. Its components are uniformly distributed at the molecular or ionic level.
Fișa 336
Întrebare
How do solute and solvent differ?
Răspuns
The solute is dissolved; the solvent is the dissolving medium. The solvent is often present in greater amount.
Fișa 337
Întrebare
What does aqueous mean in chemistry?
Răspuns
Dissolved in water. The symbol
(aq)marks an aqueous species in an equation.Fișa 338
Întrebare
What does concentration describe?
Răspuns
The amount of solute in a given amount of solution or solvent. Different units express it in different ways.
Fișa 339
Întrebare
What is molarity?
Răspuns
Moles of solute per liter of solution. Its unit is mol/L, written M.
Fișa 340
Întrebare
What is the molarity of 0.50 mol solute in 2.0 L of solution?
Răspuns
0.25 M. Divide 0.50 mol by 2.0 L.
Fișa 341
Întrebare
What stays constant when water is added to dilute a solution without reaction?
Răspuns
The moles of solute. Volume increases and concentration decreases.
Fișa 342
Întrebare
Which equation relates concentration and volume before and after a dilution?
Răspuns
M₁V₁ = M₂V₂. It follows from conserving the amount of solute.
Fișa 343
Întrebare
What is solubility?
Răspuns
The maximum concentration of a solute that can be achieved in a solution at equilibrium under specified conditions. Temperature and the substances involved matter.
Fișa 344
Întrebare
What is a saturated solution?
Răspuns
A solution holding the maximum dissolved solute at those conditions. Extra solute remains undissolved at equilibrium.
Fișa 345
Întrebare
What is an electrolyte?
Răspuns
A substance that produces mobile ions in solution and conducts electricity. Soluble ionic compounds are common examples.
Fișa 346
Întrebare
What does 'like dissolves like' predict?
Răspuns
Substances with similar polarity tend to mix well. Polar solvents favor polar or ionic solutes; nonpolar solvents favor nonpolar solutes.
Fișa 347
Întrebare
Does heating always increase solubility?
Răspuns
No. Many solids become more soluble in water, but gases usually become less soluble as temperature rises.
Fișa 348
Întrebare
What is an unsaturated solution?
Răspuns
A solution that can dissolve more solute at the stated conditions. It is below the solubility limit.
Fișa 349
Întrebare
What does a Brønsted-Lowry acid donate?
Răspuns
A proton, H⁺. In water, acid behavior increases hydronium-ion concentration.
Fișa 350
Întrebare
What does pH describe?
Răspuns
The hydronium-ion concentration on a logarithmic scale. Lower pH means higher hydronium concentration.
Fișa 351
Întrebare
At 25 °C, what pH range is acidic?
Răspuns
Below 7. A neutral aqueous solution is pH 7 at this temperature.
Fișa 352
Întrebare
How does hydronium concentration change when pH drops by 1 unit?
Răspuns
It increases tenfold. The pH scale is logarithmic.
Fișa 353
Întrebare
What does a Brønsted-Lowry base accept?
Răspuns
A proton, H⁺. Many bases in water also increase hydroxide-ion concentration.
Fișa 354
Întrebare
At 25 °C, what is the relationship between pH and pOH?
Răspuns
pH + pOH = 14. pOH is the negative base-10 logarithm of hydroxide-ion concentration; this relation applies to aqueous solutions at 25 °C.
Fișa 355
Întrebare
At 25 °C, what pH range is basic?
Răspuns
Above 7. Basic solutions have less hydronium and more hydroxide than neutral water.
Fișa 356
Întrebare
What are typical products of a strong acid reacting with a strong base?
Răspuns
Water and an ionic salt. Hydrogen ions and hydroxide ions combine to form water.
Fișa 357
Întrebare
What does strong mean for an acid or base?
Răspuns
It produces its characteristic ions essentially completely in water. Strong acids ionize; soluble ionic strong bases dissociate. Strength is separate from concentration.
Fișa 358
Întrebare
What does a buffer do?
Răspuns
It resists large pH changes when small amounts of acid or base are added. A weak conjugate acid-base pair neutralizes much of the added H₃O⁺ or OH⁻.
Fișa 359
Întrebare
How does an acid-base indicator work?
Răspuns
Its color depends on pH. The change occurs over a characteristic pH range.
Fișa 360
Întrebare
A solution has pH 9 at 25 °C. What is its pOH?
Răspuns
5. Subtract the pH from 14.
Fișa 361
Întrebare
How does a concentrated weak acid differ from a dilute strong acid?
Răspuns
Concentration tells how much acid is present; strength tells how completely it ionizes. A concentrated weak acid contains more partially ionizing acid, while a dilute strong acid contains less acid that ionizes essentially completely. Either can have the lower pH.
Fișa 362
Întrebare
What is the SI base unit of length?
Răspuns
The meter (m). Centimeters and millimeters are decimal subdivisions of a meter.
Fișa 363
Întrebare
Which tool directly measures mass in a laboratory?
Răspuns
A balance. A spring scale measures force, often reported as weight.
Fișa 364
Întrebare
What is the SI base unit of mass?
Răspuns
The kilogram (kg). Laboratory mass is also commonly reported in grams.
Fișa 365
Întrebare
A student needs to measure about 35 mL of liquid and can choose a beaker or graduated cylinder. Which should they use?
Răspuns
A graduated cylinder. Read the scale at eye level.
Fișa 366
Întrebare
What is the SI base unit of time?
Răspuns
The second (s). Minutes and hours are accepted for many everyday uses.
Fișa 367
Întrebare
Where should the volume of a clear water-based liquid be read in a graduated cylinder?
Răspuns
At the bottom of the meniscus. Keep your eye level with the liquid surface.
Fișa 368
Întrebare
What is the SI base unit of thermodynamic temperature?
Răspuns
The kelvin (K). Degrees Celsius are widely used for laboratory and body temperatures.
Fișa 369
Întrebare
Which tool measures temperature?
Răspuns
A thermometer. Its range and resolution should match the task.
Fișa 370
Întrebare
What factor does the metric prefix kilo- represent?
Răspuns
One thousand, or 10³. One kilometer equals 1,000 meters.
Fișa 371
Întrebare
A ruler's smallest marking is 1 mm. To what place should a careful analog reading usually be estimated?
Răspuns
One place beyond the smallest marking, when the scale allows it. The final digit is uncertain.
Fișa 372
Întrebare
What is measurement accuracy?
Răspuns
Closeness to an accepted or true value. A systematic error can make precise measurements inaccurate.
Fișa 373
Întrebare
How do mass and weight differ?
Răspuns
Mass is the amount of matter; weight is gravitational force on that mass. Mass stays constant when gravity changes, but weight does not.
Fișa 374
Întrebare
What factor does the metric prefix milli- represent?
Răspuns
One thousandth, or 10⁻³. One milliliter is 0.001 liter.
Fișa 375
Întrebare
How can the volume of an irregular solid be measured with water?
Răspuns
Use water displacement. Subtract the initial water volume from the final volume after submerging the object.
Fișa 376
Întrebare
What is measurement precision?
Răspuns
Closeness of repeated measurements to one another. Precise results can still be consistently wrong.
Fișa 377
Întrebare
What is an instrument's resolution?
Răspuns
The smallest change it can meaningfully display or distinguish. Higher resolution does not automatically guarantee accuracy.
Fișa 378
Întrebare
How many centimeters are in 2.5 meters?
Răspuns
2.5 × 10² cm (250 cm). Multiply meters by the exact conversion factor 100 cm/m.
Fișa 379
Întrebare
Why must a numerical measurement include a unit?
Răspuns
The unit identifies the quantity's scale. A bare number is ambiguous and cannot be compared reliably.
Fișa 380
Întrebare
What is a scientific observation?
Răspuns
Information recorded with senses or instruments. It should be distinguished from an explanation of what was observed.
Fișa 381
Întrebare
What makes a hypothesis scientifically useful?
Răspuns
It is testable and falsifiable. Evidence must be able to count against it.
Fișa 382
Întrebare
What is a scientific theory?
Răspuns
A broad, well-supported explanation of natural phenomena. It is not a casual guess and can be revised with new evidence.
Fișa 383
Întrebare
Which claim is falsifiable: 'No possible observation could count against this treatment's effectiveness' or 'This treatment lowers mean temperature within one hour'?
Răspuns
The claim that the treatment lowers mean temperature within one hour. An observation could count against it, so evidence can test it.
Fișa 384
Întrebare
What is an inference?
Răspuns
A logical interpretation based on observations and prior knowledge. It goes beyond the raw measurement.
Fișa 385
Întrebare
How does a prediction relate to a hypothesis?
Răspuns
It states an expected result if the hypothesis is correct. Experiments compare observed results with that expectation.
Fișa 386
Întrebare
How does a scientific law differ from a scientific theory?
Răspuns
A law describes a consistent pattern; a theory explains how or why patterns occur. One does not mature into the other.
Fișa 387
Întrebare
What does reliability mean for a measurement or procedure?
Răspuns
It produces consistent results under the same conditions. Repetition helps assess reliability.
Fișa 388
Întrebare
What does a correlation show?
Răspuns
Two variables change together in a patterned way. Correlation alone does not establish that one causes the other.
Fișa 389
Întrebare
What is bias in scientific work?
Răspuns
A systematic influence that pushes observations, selection, or interpretation in one direction. Good design tries to prevent or measure it.
Fișa 390
Întrebare
What is the purpose of scientific peer review?
Răspuns
Independent experts evaluate methods, reasoning, and reporting before publication. It improves scrutiny but does not guarantee truth.
Fișa 391
Întrebare
What does validity ask about a study or measurement?
Răspuns
Whether it measures or tests what it claims to measure or test. Consistency alone does not ensure validity.
Fișa 392
Întrebare
What evidence most strengthens a causal claim?
Răspuns
A well-controlled experiment that manipulates the suspected cause. Random assignment reduces confounding, while independent replication tests whether the result holds with new data.
Fișa 393
Întrebare
What is a primary scientific source?
Răspuns
A report of original methods, data, and results. A review article synthesizes many primary studies.
Fișa 394
Întrebare
How should an unexpected outlier be handled?
Răspuns
Investigate and report it rather than deleting it automatically. Exclusion needs a documented scientific reason.
Fișa 395
Întrebare
What is a confounding variable?
Răspuns
An outside factor related to both the suspected cause and the outcome. It can create a misleading association.
Fișa 396
Întrebare
Why should a sample represent the population of interest?
Răspuns
Results generalize poorly when important groups are missing or overrepresented. Sampling method matters as much as size.
Fișa 397
Întrebare
What is a scientific model?
Răspuns
A simplified representation used to explain or predict a system. A model is useful within its assumptions and limits.
Fișa 398
Întrebare
Why should measurements report uncertainty or reasonable precision?
Răspuns
Every measurement has limits. Reporting more digits than the method supports creates false precision.
Fișa 399
Întrebare
If results match a prediction once, what is the safest conclusion?
Răspuns
The results support the hypothesis under those conditions. One result does not prove the hypothesis in every setting.
Fișa 400
Întrebare
What is a direct relationship between two variables?
Răspuns
As one increases, the other tends to increase; as one decreases, the other tends to decrease. The relationship need not be perfectly linear.
Fișa 401
Întrebare
Which variable is usually placed on the x-axis of an experimental graph?
Răspuns
The independent variable. It is the factor selected or changed by the investigator.
Fișa 402
Întrebare
What does the slope of a straight-line graph represent?
Răspuns
Change in y divided by change in x. It is the response rate per unit change in the other variable.
Fișa 403
Întrebare
A line rises 12 units in y while x rises 3 units. What is its slope?
Răspuns
4 units of y per unit of x. Divide 12 by 3.
Fișa 404
Întrebare
What is an inverse relationship?
Răspuns
As one variable increases, the other tends to decrease. Their product is constant only in a strictly inverse proportion.
Fișa 405
Întrebare
Which variable is usually placed on the y-axis of an experimental graph?
Răspuns
The dependent variable. It is the measured response.
Fișa 406
Întrebare
What does a plateau on a response graph indicate?
Răspuns
The measured response has stopped changing much despite further x increases. A limiting factor may have been reached.
Fișa 407
Întrebare
What is interpolation?
Răspuns
Estimating a value within the range of measured data. It is generally safer than extrapolating beyond that range.
Fișa 408
Întrebare
What pattern suggests no relationship between two plotted variables?
Răspuns
The response shows no consistent change as the other variable changes. Points may scatter without a trend.
Fișa 409
Întrebare
Before comparing values in a data table, what should you check?
Răspuns
Headings, units, and conditions. Numbers from different measures or scales cannot be compared directly.
Fișa 410
Întrebare
If 3 samples require 12 mL total, how much is needed for 5 equal samples?
Răspuns
20 mL. The rate is 4 mL per sample, so multiply by 5.
Fișa 411
Întrebare
How is the arithmetic mean calculated?
Răspuns
Add all values and divide by the number of values. A large outlier can shift the mean.
Fișa 412
Întrebare
Why is extrapolation uncertain?
Răspuns
It assumes the observed trend continues outside measured conditions. The relationship may change beyond the data range.
Fișa 413
Întrebare
A culture grows from 20 to 50 cells in 6 hours. What is the average growth rate?
Răspuns
5 cells per hour. The change is 30 cells divided by 6 hours.
Fișa 414
Întrebare
A measurement rises from 40 to 50. What is the percent increase?
Răspuns
25%. The increase is 10, and 10 ÷ 40 × 100 = 25%.
Fișa 415
Întrebare
When can the median describe a typical value better than the mean?
Răspuns
When data are skewed or contain strong outliers. In an ordered set, the median is the middle value for an odd count and the mean of the two middle values for an even count.
Fișa 416
Întrebare
How do quantitative and qualitative data differ?
Răspuns
Quantitative data are numerical; qualitative data describe categories or qualities. Both can answer scientific questions.
Fișa 417
Întrebare
A response is 2 at dose 1, 4 at dose 2, and 8 at dose 4. If the relationship is linear, what response is predicted at dose 3?
Răspuns
6. The observed rate is 2 response units per dose unit, so interpolation at dose 3 gives 6.
Fișa 418
Întrebare
How can a graph reveal a nonlinear relationship?
Răspuns
The points follow a curve rather than a straight line. The rate of change varies across the x-range.
Fișa 419
Întrebare
What is the range of a data set?
Răspuns
Maximum minus minimum. It describes total spread but ignores the distribution between the endpoints.
Fișa 420
Întrebare
What makes a scientific research question testable?
Răspuns
It identifies measurable variables or observable outcomes. The needed data must be obtainable.
Fișa 421
Întrebare
In an experiment, what is the independent variable?
Răspuns
The factor deliberately changed or assigned by the investigator. In a simple one-factor experiment, changing one independent variable helps isolate its effect.
Fișa 422
Întrebare
What should a hypothesis connect?
Răspuns
A proposed explanation with a measurable outcome. It should lead to a prediction that evidence can challenge.
Fișa 423
Întrebare
What is a controlled variable, or constant?
Răspuns
A condition kept the same across groups. Holding it constant prevents it from explaining outcome differences.
Fișa 424
Întrebare
What is the purpose of a control group?
Răspuns
It provides a comparison without the experimental treatment. Differences can then be attributed more confidently to the treatment.
Fișa 425
Întrebare
In an experiment, what is the dependent variable?
Răspuns
The measured response. It may change because of the independent variable.
Fișa 426
Întrebare
What form can a useful experimental prediction take?
Răspuns
If the independent variable changes in a stated way, then the dependent variable should respond in a stated way. The reason links it to the hypothesis.
Fișa 427
Întrebare
What does a positive control demonstrate?
Răspuns
That the setup can produce a known response. If it fails, the test system may be defective.
Fișa 428
Întrebare
Why randomly assign subjects to experimental groups?
Răspuns
To distribute known and unknown differences more evenly. This reduces selection bias and confounding.
Fișa 429
Întrebare
How can blinding reduce bias?
Răspuns
It keeps participants, observers, or both unaware of treatment assignments. Expectations are less likely to affect behavior or measurement.
Fișa 430
Întrebare
What is a placebo?
Răspuns
An inactive treatment designed to resemble the experimental treatment. It helps separate treatment effects from expectation effects.
Fișa 431
Întrebare
What does a negative control demonstrate?
Răspuns
What happens when the tested cause is absent. An unexpected response may reveal contamination or another source.
Fișa 432
Întrebare
Why does a larger sample often improve a study?
Răspuns
It reduces the influence of chance variation and supports more stable estimates. It cannot repair a biased sampling method.
Fișa 433
Întrebare
Why repeat trials within an experiment?
Răspuns
To estimate variability and check consistency. One unusual trial then has less influence.
Fișa 434
Întrebare
Why must an experimental procedure be detailed and standardized?
Răspuns
So groups are treated consistently and others can reproduce the work. Uncontrolled procedural differences create alternative explanations.
Fișa 435
Întrebare
Why calibrate a measuring instrument before collecting data?
Răspuns
To compare its readings with a known standard and reduce systematic error. Calibration improves confidence in accuracy.
Fișa 436
Întrebare
What is an operational definition?
Răspuns
A precise statement of how a variable is measured or manipulated. It turns an abstract concept into a repeatable procedure.
Fișa 437
Întrebare
How does independent replication differ from repeated trials?
Răspuns
Independent replication repeats a study with independently collected data, often by a different investigator; repeated trials rerun measurements within the original experiment. Replication tests consistency across separate studies.
Fișa 438
Întrebare
Why should raw data be recorded before interpretation?
Răspuns
It preserves the observations separately from conclusions. Others can check calculations and reasoning.
Fișa 439
Întrebare
What should a scientific conclusion do?
Răspuns
Answer the research question using the data and acknowledge limits. It should not claim more than the design supports.
Fișa 440
Întrebare
What should happen when data do not support a hypothesis?
Răspuns
Revise or reject the hypothesis and consider new tests. Data should not be altered to preserve the original idea.
Fișa 441
Întrebare
What is a study limitation?
Răspuns
A feature that restricts interpretation or generalization. Small samples, short duration, and imperfect measurements are examples.
Fișa 442
Întrebare
Why are ethics part of experimental design?
Răspuns
Research must protect participants, organisms, and communities while balancing risks and benefits. Consent and humane treatment are key examples.
Fișa 443
Întrebare
How does an observational study differ from an experiment?
Răspuns
It measures variables without assigning the exposure. It can find associations but usually supports weaker causal conclusions.
Fișa 444
Întrebare
Plants receive 0, 2, or 4 hours of added light, and growth is measured. What is the independent variable?
Răspuns
Hours of added light. Plant growth is the dependent variable.
Fișa 445
Întrebare
A fertilizer study gives every plant the same water, soil, and temperature. What are these conditions?
Răspuns
Controlled variables. Keeping them constant isolates the fertilizer's effect.
Fișa 446
Întrebare
A drug group improves more than a control group, but the groups were not randomly assigned. What is the main caution?
Răspuns
Preexisting group differences could explain some improvement. The result is suggestive, but the design weakens a causal claim.
446 de fișe
ATI TEAS 7 Science Flashcards: A&P, Biology, Chemistry & Scientific Reasoning
Nibomo se deschide ca să poți începe să studiezi.