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