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