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.

Kuhusu fungu hili

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.

Kadi za fungu hili

  1. Kadi namba 1

    Swali

    What posture defines the standard anatomical position?

    Jibu

    Standing upright, facing forward, with arms at the sides and palms forward. The feet point forward, giving anatomy a consistent reference position.

  2. Kadi namba 2

    Swali

    In anatomical language, what does superior mean?

    Jibu

    Toward the head or above another structure. Inferior means toward the feet or below.

  3. Kadi namba 3

    Swali

    Which anatomical plane divides the body into left and right portions?

    Jibu

    The sagittal plane. A midsagittal plane divides the body into equal left and right halves.

  4. Kadi namba 4

    Swali

    Why does the body use feedback mechanisms?

    Jibu

    To regulate internal conditions. Feedback compares a condition with a set range and triggers responses that adjust it.

  5. Kadi namba 5

    Swali

    What is the order of structural organization from simplest to most complex?

    Jibu

    Chemical, cellular, tissue, organ, organ system, organism. Each level builds on interactions at the preceding level.

  6. Kadi namba 6

    Swali

    What does anterior mean in human anatomy?

    Jibu

    Toward the front of the body. Posterior means toward the back.

  7. Kadi namba 7

    Swali

    Which plane divides the body into upper and lower portions?

    Jibu

    The transverse plane. It is also called the horizontal plane.

  8. Kadi namba 8

    Swali

    What is homeostasis?

    Jibu

    The maintenance of a relatively stable internal environment. It is dynamic rather than perfectly unchanging.

  9. Kadi namba 9

    Swali

    Which major body cavity contains the brain and spinal cord?

    Jibu

    The dorsal body cavity. Its cranial cavity holds the brain, and its vertebral cavity holds the spinal cord.

  10. Kadi namba 10

    Swali

    What does medial mean in anatomical language?

    Jibu

    Toward the body's midline. Lateral means farther from the midline.

  11. Kadi namba 11

    Swali

    A rise in body temperature triggers sweating. What control pattern is this?

    Jibu

    Negative feedback. The response opposes the original temperature change and moves the body toward its normal range.

  12. Kadi namba 12

    Swali

    Which anatomical plane divides the body into front and back portions?

    Jibu

    The frontal, or coronal, plane. It separates anterior from posterior portions.

  13. Kadi namba 13

    Swali

    Which major body cavity contains the thoracic and abdominopelvic cavities?

    Jibu

    The ventral body cavity. The diaphragm separates its thoracic and abdominopelvic portions.

  14. Kadi namba 14

    Swali

    What does proximal mean when describing a limb?

    Jibu

    Closer to the limb's point of attachment. Distal means farther from that point.

  15. Kadi namba 15

    Swali

    How does positive feedback differ from negative feedback?

    Jibu

    Positive feedback amplifies the initial change. Negative feedback opposes a change; positive feedback continues until a stopping event occurs.

  16. Kadi namba 16

    Swali

    Which tissue type covers surfaces and lines body cavities?

    Jibu

    Epithelial tissue. It also forms many glands and often serves protective, absorptive, or secretory roles.

  17. Kadi namba 17

    Swali

    Which tissue type mainly supports, binds, and protects other tissues?

    Jibu

    Connective tissue. Its cells are typically separated by an extracellular matrix.

  18. Kadi namba 18

    Swali

    What shared property lets muscle tissue produce movement?

    Jibu

    Contractility. Muscle cells shorten or develop tension in response to stimulation.

  19. Kadi namba 19

    Swali

    Which tissue type rapidly communicates by electrical signals?

    Jibu

    Nervous tissue. Neurons transmit signals, while supporting cells help maintain their environment.

  20. Kadi namba 20

    Swali

    Why are tightly packed epithelial cells well suited for barriers?

    Jibu

    They leave little space between cells. This continuous arrangement limits passage across a surface.

  21. Kadi namba 21

    Swali

    What distinguishes connective tissue from epithelial tissue?

    Jibu

    Connective tissue usually has abundant extracellular matrix. Epithelial cells are more tightly packed.

  22. Kadi namba 22

    Swali

    What are the four basic human tissue types?

    Jibu

    Epithelial, connective, muscle, and nervous tissue. Organs contain two or more tissue types working together.

  23. Kadi namba 23

    Swali

    What makes a structure an organ rather than a tissue?

    Jibu

    An organ combines multiple tissue types for a specific function. A tissue is a group of similar cells and matrix performing related work.

  24. Kadi namba 24

    Swali

    What are the skeletal system's main functions?

    Jibu

    Support, protection, movement, mineral storage, blood-cell production, and fat storage. Bones also provide levers for muscles.

  25. Kadi namba 25

    Swali

    What belongs to the axial skeleton?

    Jibu

    The skull, vertebral column, and thoracic cage. These structures form the body's central axis.

  26. Kadi namba 26

    Swali

    How do compact and spongy bone differ?

    Jibu

    Compact bone is dense; spongy bone has a lattice of trabeculae. Both are organized living bone tissue.

  27. Kadi namba 27

    Swali

    What is a joint?

    Jibu

    A place where two or more bones meet. Joint structure determines how much movement is possible.

  28. Kadi namba 28

    Swali

    Which bone cell builds new bone matrix?

    Jibu

    An osteoblast. Osteoclasts break down bone, while osteocytes maintain mature bone tissue.

  29. Kadi namba 29

    Swali

    What belongs to the appendicular skeleton?

    Jibu

    The limbs plus the shoulder and pelvic girdles. It attaches the limbs to the axial skeleton.

  30. Kadi namba 30

    Swali

    What is the main role of red bone marrow?

    Jibu

    Blood-cell production. This process is called hematopoiesis.

  31. Kadi namba 31

    Swali

    Which joint class allows the greatest range of motion?

    Jibu

    A synovial joint. A fluid-filled joint cavity reduces friction between articulating surfaces.

  32. Kadi namba 32

    Swali

    Which bone cell breaks down bone matrix?

    Jibu

    An osteoclast. Bone resorption helps remodeling and mineral balance.

  33. Kadi namba 33

    Swali

    What does a ligament connect?

    Jibu

    Bone to bone. A tendon connects muscle to bone.

  34. Kadi namba 34

    Swali

    What is the shaft of a long bone called?

    Jibu

    The diaphysis. The enlarged ends are the epiphyses.

  35. Kadi namba 35

    Swali

    Why is bone important to blood-calcium balance?

    Jibu

    Bone stores calcium and can release or absorb it during remodeling. Hormones regulate this exchange.

  36. Kadi namba 36

    Swali

    What is stored mainly in yellow bone marrow?

    Jibu

    Fat. It serves as an energy reserve.

  37. Kadi namba 37

    Swali

    What does articular cartilage do at a synovial joint?

    Jibu

    It reduces friction and absorbs shock. It covers the ends of articulating bones.

  38. Kadi namba 38

    Swali

    Why must a broken bone receive a blood supply during healing?

    Jibu

    Repairing cells need oxygen and nutrients. Restored blood vessels support fracture healing.

  39. Kadi namba 39

    Swali

    What is bone remodeling?

    Jibu

    Continuous removal and replacement of bone tissue. It repairs microdamage and helps bones adapt to stress.

  40. Kadi namba 40

    Swali

    Which muscle tissue is usually under voluntary control?

    Jibu

    Skeletal muscle. Most skeletal muscles move the skeleton, while some, such as facial muscles, insert into skin or other soft tissue.

  41. Kadi namba 41

    Swali

    What is a sarcomere?

    Jibu

    The basic contractile unit of striated muscle. It lies between two Z discs.

  42. Kadi namba 42

    Swali

    What does a tendon connect?

    Jibu

    Muscle to bone. It transmits muscle force to the skeleton.

  43. Kadi namba 43

    Swali

    Which proteins slide past one another during muscle contraction?

    Jibu

    Actin and myosin. Their interaction shortens sarcomeres without shortening the filaments themselves.

  44. Kadi namba 44

    Swali

    Where is smooth muscle commonly found?

    Jibu

    In the walls of hollow organs and blood vessels. Its contractions are generally involuntary.

  45. Kadi namba 45

    Swali

    What ion exposes binding sites needed for skeletal muscle contraction?

    Jibu

    Calcium. Its release inside the muscle fiber allows actin and myosin interaction.

  46. Kadi namba 46

    Swali

    How do antagonistic muscle pairs move a joint?

    Jibu

    One muscle contracts while the opposing muscle relaxes. Reversing their roles moves the joint in the opposite direction.

  47. Kadi namba 47

    Swali

    Why does muscle contraction require ATP?

    Jibu

    ATP powers cross-bridge cycling and ion pumps. It is also needed for myosin to detach from actin.

  48. Kadi namba 48

    Swali

    Which muscle tissue makes up the heart wall?

    Jibu

    Cardiac muscle. It is striated, involuntary, and connected for coordinated pumping.

  49. Kadi namba 49

    Swali

    During a typical muscle contraction, which attachment moves more: origin or insertion?

    Jibu

    The insertion. The origin is generally the more fixed attachment.

  50. Kadi namba 50

    Swali

    Which type of neuron sends the signal that initiates skeletal-muscle contraction?

    Jibu

    A somatic motor neuron. It releases acetylcholine at the neuromuscular junction, triggering an action potential in the muscle fiber.

  51. Kadi namba 51

    Swali

    What is muscle tone?

    Jibu

    Continuous low-level muscle tension. It helps maintain posture and readiness without producing a large movement.

  52. Kadi namba 52

    Swali

    How does skeletal muscle help regulate body temperature?

    Jibu

    Contraction releases heat. Shivering increases rapid contractions when the body is cold.

  53. Kadi namba 53

    Swali

    What are the three muscle tissue types?

    Jibu

    Skeletal, cardiac, and smooth muscle. They differ in location, structure, and control.

  54. Kadi namba 54

    Swali

    What is a neuron's main function?

    Jibu

    To receive, process, and transmit information. Neurons use electrical signals and chemical messengers.

  55. Kadi namba 55

    Swali

    What structures make up the central nervous system?

    Jibu

    The brain and spinal cord. They integrate information and coordinate responses.

  56. Kadi namba 56

    Swali

    Which part of a neuron usually receives incoming signals?

    Jibu

    The dendrites. The cell body integrates much of that input.

  57. Kadi namba 57

    Swali

    What does the peripheral nervous system include?

    Jibu

    Nerves and ganglia outside the brain and spinal cord. It links the central nervous system with the rest of the body.

  58. Kadi namba 58

    Swali

    Which neuron structure carries an impulse away from the cell body?

    Jibu

    The axon. Its terminals communicate with another cell.

  59. Kadi namba 59

    Swali

    Which nervous-system division controls skeletal muscles voluntarily?

    Jibu

    The somatic nervous system. It also carries sensory information from skin, muscles, and joints.

  60. Kadi namba 60

    Swali

    What is a synapse?

    Jibu

    A junction where one neuron communicates with another cell. Chemical synapses use neurotransmitters across a small gap.

  61. Kadi namba 61

    Swali

    Which nervous-system division regulates organs and glands without conscious control?

    Jibu

    The autonomic nervous system. It includes sympathetic and parasympathetic divisions.

  62. Kadi namba 62

    Swali

    How does myelin affect nerve signaling?

    Jibu

    It speeds impulse conduction along an axon. Myelin insulates segments of the axon.

  63. Kadi namba 63

    Swali

    Which autonomic division prepares the body for acute activity?

    Jibu

    The sympathetic division. It generally increases alertness and supports a fight-or-flight response.

  64. Kadi namba 64

    Swali

    What is a reflex?

    Jibu

    A rapid, predictable response to a stimulus. A reflex pathway can act before conscious awareness.

  65. Kadi namba 65

    Swali

    Which autonomic division supports rest, digestion, and energy conservation?

    Jibu

    The parasympathetic division. It generally promotes routine maintenance functions.

  66. Kadi namba 66

    Swali

    Which brain region is most associated with conscious thought and voluntary movement?

    Jibu

    The cerebrum. Its cortex also processes much sensory information.

  67. Kadi namba 67

    Swali

    Which brain region fine-tunes balance and coordinated movement?

    Jibu

    The cerebellum. It compares intended movement with sensory feedback.

  68. Kadi namba 68

    Swali

    Which brain region controls vital automatic functions such as breathing and heart rate?

    Jibu

    The brainstem. It also connects higher brain regions with the spinal cord.

  69. Kadi namba 69

    Swali

    How do sensory and motor neurons differ?

    Jibu

    Sensory neurons carry information toward the CNS; motor neurons carry commands away. Interneurons connect and process signals within the CNS.

  70. Kadi namba 70

    Swali

    What does a sensory receptor do?

    Jibu

    It converts a stimulus into a neural signal. Different receptors respond best to particular forms of energy or chemicals.

  71. Kadi namba 71

    Swali

    What is a hormone?

    Jibu

    A chemical messenger released into body fluids to affect target cells. A target responds only if it has the appropriate receptor.

  72. Kadi namba 72

    Swali

    Why is the pituitary gland often called a master gland?

    Jibu

    Several pituitary hormones regulate other endocrine glands. The hypothalamus controls much of pituitary activity.

  73. Kadi namba 73

    Swali

    Why can one hormone affect some cells but not others?

    Jibu

    Only target cells have the matching receptor. Receptor binding starts the cell's response.

  74. Kadi namba 74

    Swali

    Which gland produces hormones that broadly increase metabolic activity?

    Jibu

    The thyroid gland. Thyroid hormones influence energy use and development.

  75. Kadi namba 75

    Swali

    What is insulin's main effect on blood glucose?

    Jibu

    It lowers blood glucose. Insulin promotes glucose uptake and storage after a meal.

  76. Kadi namba 76

    Swali

    Which glands release a hormone that raises blood calcium?

    Jibu

    The parathyroid glands. Parathyroid hormone acts on bone, kidneys, and vitamin D pathways.

  77. Kadi namba 77

    Swali

    Which adrenal region releases epinephrine during acute stress?

    Jibu

    The adrenal medulla. Its hormones reinforce sympathetic nervous-system effects.

  78. Kadi namba 78

    Swali

    Which organ has both endocrine and digestive functions?

    Jibu

    The pancreas. Its islets release hormones, while other cells release digestive enzymes.

  79. Kadi namba 79

    Swali

    What is glucagon's main effect on blood glucose?

    Jibu

    It raises blood glucose. It promotes release of stored glucose during fasting.

  80. Kadi namba 80

    Swali

    Rising thyroid hormone reduces its own upstream stimulation. What pattern is this?

    Jibu

    Negative feedback. The final hormone limits further release along the control pathway.

  81. Kadi namba 81

    Swali

    Which adrenal region produces steroid hormones such as cortisol and aldosterone?

    Jibu

    The adrenal cortex. It surrounds the adrenal medulla.

  82. Kadi namba 82

    Swali

    Which gland releases melatonin and helps regulate daily sleep timing?

    Jibu

    The pineal gland. Light information influences its secretion pattern.

  83. Kadi namba 83

    Swali

    Which hormone directly increases collecting-duct water permeability?

    Jibu

    Antidiuretic hormone, or ADH. It makes collecting ducts more permeable to water, increasing water reabsorption and usually producing less, more concentrated urine.

  84. Kadi namba 84

    Swali

    Which hormone strengthens uterine contractions during labor?

    Jibu

    Oxytocin. This is a classic positive-feedback pathway that ends after delivery.

  85. Kadi namba 85

    Swali

    How does endocrine signaling generally differ from nervous signaling?

    Jibu

    It is usually slower to start and longer lasting. Hormones travel through body fluids, while neurons signal specific targets rapidly.

  86. Kadi namba 86

    Swali

    What is plasma?

    Jibu

    The liquid portion of blood. It carries cells, nutrients, hormones, proteins, wastes, and dissolved gases.

  87. Kadi namba 87

    Swali

    Which side of the heart pumps blood to the lungs?

    Jibu

    The right side. The right ventricle sends deoxygenated blood through the pulmonary trunk and arteries.

  88. Kadi namba 88

    Swali

    What is the main function of red blood cells?

    Jibu

    Transporting oxygen. Their hemoglobin also carries a smaller share of carbon dioxide.

  89. Kadi namba 89

    Swali

    What defines an artery?

    Jibu

    It carries blood away from the heart. Oxygen content does not define it; pulmonary arteries carry deoxygenated blood.

  90. Kadi namba 90

    Swali

    What is the main function of white blood cells?

    Jibu

    Body defense. Different white blood cells recognize, attack, or coordinate responses to threats.

  91. Kadi namba 91

    Swali

    Which side of the heart pumps blood into systemic circulation?

    Jibu

    The left side. The left ventricle sends oxygenated blood into the aorta.

  92. Kadi namba 92

    Swali

    What is the main purpose of heart valves?

    Jibu

    To keep blood moving in one direction. Pressure differences open and close them.

  93. Kadi namba 93

    Swali

    What defines a vein?

    Jibu

    It carries blood toward the heart. Many veins contain valves that limit backflow.

  94. Kadi namba 94

    Swali

    What is the main role of platelets?

    Jibu

    Helping stop bleeding. They form a platelet plug and support clotting reactions at a damaged vessel.

  95. Kadi namba 95

    Swali

    Why are capillaries well suited for exchange?

    Jibu

    Their walls are only one cell layer thick. Their small diameter and large total surface area support diffusion and filtration.

  96. Kadi namba 96

    Swali

    After blood enters the right atrium, what chamber receives it next?

    Jibu

    The right ventricle. Blood passes through the tricuspid valve before entering that chamber.

  97. Kadi namba 97

    Swali

    What happens during ventricular systole?

    Jibu

    The ventricles contract and eject blood. The right ventricle pumps to the lungs, and the left pumps to the body.

  98. Kadi namba 98

    Swali

    What is pulmonary circulation?

    Jibu

    Blood flow between the heart and lungs. It allows gas exchange and returns oxygenated blood to the left atrium.

  99. Kadi namba 99

    Swali

    What normally sets the heart's rhythm?

    Jibu

    The sinoatrial, or SA, node. Its spontaneous electrical activity initiates each heartbeat.

  100. Kadi namba 100

    Swali

    What molecule in red blood cells binds oxygen?

    Jibu

    Hemoglobin. Its iron-containing heme groups bind oxygen reversibly.

  101. Kadi namba 101

    Swali

    What happens during ventricular diastole?

    Jibu

    The ventricles relax and fill. Atrioventricular valves are open during most ventricular filling.

  102. Kadi namba 102

    Swali

    What is systemic circulation?

    Jibu

    Blood flow between the heart and the body's tissues. It delivers oxygen and nutrients and returns wastes.

  103. Kadi namba 103

    Swali

    What does arterial blood pressure measure?

    Jibu

    The force of blood against artery walls. It is commonly reported as systolic over diastolic pressure.

  104. Kadi namba 104

    Swali

    What do coronary arteries supply?

    Jibu

    The heart muscle itself. Blocked coronary blood flow can deprive myocardium of oxygen.

  105. Kadi namba 105

    Swali

    Which major vessels return systemic blood to the right atrium?

    Jibu

    The superior and inferior venae cavae. The superior vessel drains the upper body; the inferior drains the lower body.

  106. Kadi namba 106

    Swali

    What is the respiratory system's primary gas-exchange function?

    Jibu

    Bringing oxygen into the body and removing carbon dioxide. Ventilation moves air, while diffusion exchanges gases.

  107. Kadi namba 107

    Swali

    What is the airflow sequence from the pharynx to the gas-exchange surfaces?

    Jibu

    Pharynx, larynx, trachea, bronchi, bronchioles, alveoli. Each branch conducts air deeper into the lungs.

  108. Kadi namba 108

    Swali

    Where does most gas exchange occur in the lungs?

    Jibu

    Across the alveolar-capillary membrane. Thin walls and a large surface area shorten diffusion distance.

  109. Kadi namba 109

    Swali

    What does the diaphragm do during quiet inhalation?

    Jibu

    It contracts and moves downward. Thoracic volume rises, lung pressure falls, and air flows inward.

  110. Kadi namba 110

    Swali

    Why does oxygen move from alveoli into pulmonary capillaries?

    Jibu

    Its partial pressure is higher in alveolar air than in incoming blood. Oxygen diffuses down that gradient.

  111. Kadi namba 111

    Swali

    What drives quiet exhalation?

    Jibu

    Elastic recoil after inspiratory muscles relax. Thoracic volume falls and pressure pushes air outward.

  112. Kadi namba 112

    Swali

    What is the pleura?

    Jibu

    A double membrane surrounding each lung. A thin fluid layer reduces friction during breathing.

  113. Kadi namba 113

    Swali

    How is most oxygen transported in blood?

    Jibu

    Bound to hemoglobin in red blood cells. Only a small amount dissolves directly in plasma.

  114. Kadi namba 114

    Swali

    Why does carbon dioxide move from pulmonary blood into alveoli?

    Jibu

    Its partial pressure is higher in incoming blood than in alveolar air. It diffuses down that gradient for exhalation.

  115. Kadi namba 115

    Swali

    What helps keep swallowed material out of the airway?

    Jibu

    The epiglottis and coordinated swallowing reflexes. The laryngeal opening is protected as food passes.

  116. Kadi namba 116

    Swali

    How does the conducting airway remove trapped particles?

    Jibu

    Mucus traps them, and cilia move the mucus toward the throat. This is the mucociliary escalator.

  117. Kadi namba 117

    Swali

    In what form is most carbon dioxide transported in blood?

    Jibu

    As bicarbonate ions. Red blood cells help convert carbon dioxide and water into bicarbonate.

  118. Kadi namba 118

    Swali

    Which blood change is a strong normal stimulus to increase breathing?

    Jibu

    A rise in carbon dioxide and the associated fall in pH. Brainstem centers adjust ventilation in response.

  119. Kadi namba 119

    Swali

    Why must alveoli receive both air and blood?

    Jibu

    Gas exchange needs ventilation and perfusion. Air without blood flow, or blood without airflow, cannot exchange gases effectively.

  120. Kadi namba 120

    Swali

    Why does ventilation increase during exercise?

    Jibu

    Active tissues use more oxygen and produce more carbon dioxide. Faster, deeper breathing helps meet that demand.

  121. Kadi namba 121

    Swali

    What are the digestive system's core functions?

    Jibu

    Ingestion, digestion, absorption, and elimination. Movement and secretion support those processes.

  122. Kadi namba 122

    Swali

    What is the alimentary-canal sequence after the mouth?

    Jibu

    Pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus. Food passes through this continuous tube.

  123. Kadi namba 123

    Swali

    What is mechanical digestion?

    Jibu

    Physical breakdown and mixing of food without changing its molecules. Chewing and stomach churning are examples.

  124. Kadi namba 124

    Swali

    What are two major functions of the stomach?

    Jibu

    It stores and mixes food and begins substantial protein digestion. Acid denatures proteins, converts pepsinogen to pepsin, and provides the low pH pepsin needs.

  125. Kadi namba 125

    Swali

    Where does most nutrient absorption occur?

    Jibu

    The small intestine. Folds, villi, and microvilli create a large absorptive surface.

  126. Kadi namba 126

    Swali

    Which nutrient does salivary amylase begin digesting in the mouth?

    Jibu

    Carbohydrates, especially starch. Salivary amylase breaks starch into smaller carbohydrates.

  127. Kadi namba 127

    Swali

    What is chemical digestion?

    Jibu

    Enzymatic breakdown of large food molecules into absorbable units. Chemical bonds are changed during the process.

  128. Kadi namba 128

    Swali

    What is peristalsis?

    Jibu

    Wave-like smooth-muscle contractions that move material forward. It occurs throughout much of the digestive tract.

  129. Kadi namba 129

    Swali

    What is a main function of the large intestine?

    Jibu

    Absorbing water and electrolytes and forming feces. Resident microbes also process some undigested material.

  130. Kadi namba 130

    Swali

    What digestive product does the liver make?

    Jibu

    Bile. Bile salts help disperse dietary fat into smaller droplets.

  131. Kadi namba 131

    Swali

    What does a digestive sphincter do?

    Jibu

    It regulates movement between regions of the digestive tract. Circular muscle contracts to close a passage.

  132. Kadi namba 132

    Swali

    What does the pancreas release into the small intestine?

    Jibu

    Digestive enzymes and bicarbonate-rich fluid. Bicarbonate helps neutralize acidic material from the stomach.

  133. Kadi namba 133

    Swali

    How do intestinal villi improve absorption?

    Jibu

    They increase surface area. Each villus contains blood capillaries and a lymphatic lacteal for transported nutrients.

  134. Kadi namba 134

    Swali

    What is the gallbladder's role?

    Jibu

    It stores and concentrates bile. It releases bile into the small intestine when fatty food arrives.

  135. Kadi namba 135

    Swali

    Which macronutrient's absorbed products usually enter intestinal lacteals before reaching the blood?

    Jibu

    Most dietary lipids. Their absorbed products travel through lymph before entering the bloodstream.

  136. Kadi namba 136

    Swali

    Which accessory organs help digestion without food passing through them?

    Jibu

    The teeth, tongue, salivary glands, liver, gallbladder, and pancreas. Teeth and the tongue act mechanically; the other accessory organs add or store digestive secretions.

  137. Kadi namba 137

    Swali

    What organs make up the urinary system?

    Jibu

    The kidneys, ureters, urinary bladder, and urethra. Kidneys make urine; the remaining organs transport, store, and release it.

  138. Kadi namba 138

    Swali

    What is a nephron?

    Jibu

    The kidney's functional unit. It filters blood and adjusts the filtrate to form urine.

  139. Kadi namba 139

    Swali

    Where does blood filtration begin in a nephron?

    Jibu

    At the renal corpuscle. Pressure pushes water and small solutes from glomerular capillaries into the capsule.

  140. Kadi namba 140

    Swali

    What moves urine from a kidney to the bladder?

    Jibu

    A ureter. Smooth-muscle contractions propel urine along the tube.

  141. Kadi namba 141

    Swali

    What is the urinary bladder's main role?

    Jibu

    Temporary urine storage. Stretch receptors help trigger the urge to urinate as it fills.

  142. Kadi namba 142

    Swali

    Which structure carries urine from the bladder out of the body?

    Jibu

    The urethra. It is distinct from the ureters that enter the bladder.

  143. Kadi namba 143

    Swali

    What is tubular reabsorption?

    Jibu

    Movement of useful substances from nephron fluid back into blood. Water, glucose, and ions are common examples.

  144. Kadi namba 144

    Swali

    What is the glomerulus?

    Jibu

    A capillary tuft that filters blood in the renal corpuscle. Cells and most large proteins normally remain in circulation.

  145. Kadi namba 145

    Swali

    How does more ADH change urine?

    Jibu

    It makes urine more concentrated and lowers its volume. More water is reabsorbed from the collecting ducts.

  146. Kadi namba 146

    Swali

    What path does filtrate follow after entering the glomerular capsule?

    Jibu

    Proximal convoluted tubule → nephron loop → distal convoluted tubule → collecting duct. The collecting duct receives forming urine from multiple nephrons.

  147. Kadi namba 147

    Swali

    What is tubular secretion?

    Jibu

    Movement of selected substances from blood into nephron fluid. It helps eliminate wastes and regulate ions and pH.

  148. Kadi namba 148

    Swali

    Besides removing waste, what does the urinary system regulate?

    Jibu

    Water, electrolytes, acid-base balance, and blood volume. Kidney hormones also affect blood pressure and red-cell production.

  149. Kadi namba 149

    Swali

    Why does dehydration usually reduce urine volume?

    Jibu

    The body conserves water by increasing renal reabsorption. ADH is an important signal in this response.

  150. Kadi namba 150

    Swali

    Why do the kidneys receive a large blood flow?

    Jibu

    They must continuously filter plasma and regulate its composition. High flow supports waste removal and homeostasis.

  151. Kadi namba 151

    Swali

    What is lymph?

    Jibu

    Interstitial fluid that has entered lymphatic vessels. It eventually returns to the bloodstream.

  152. Kadi namba 152

    Swali

    What is innate immunity?

    Jibu

    Rapid, nonspecific defense present before a particular exposure. Barriers, inflammation, and several immune cells contribute.

  153. Kadi namba 153

    Swali

    What is a major function of lymph nodes?

    Jibu

    Filtering lymph and providing sites for immune-cell activation. Swelling can reflect an active immune response.

  154. Kadi namba 154

    Swali

    What does the spleen filter?

    Jibu

    Blood. It removes aged blood cells and supports immune responses to blood-borne antigens.

  155. Kadi namba 155

    Swali

    What is a key function of B lymphocytes?

    Jibu

    Producing antibody-secreting cells and memory cells. Antibodies bind specific antigens.

  156. Kadi namba 156

    Swali

    What distinguishes adaptive immunity?

    Jibu

    It targets specific antigens and develops memory. Later exposure can trigger a faster, stronger response.

  157. Kadi namba 157

    Swali

    Which lymphatic organ is important for T-cell maturation?

    Jibu

    The thymus. It is most active early in life.

  158. Kadi namba 158

    Swali

    What is the body's first physical barrier against many pathogens?

    Jibu

    Intact skin and mucous membranes. Their secretions and normal microbes add protection.

  159. Kadi namba 159

    Swali

    What is a key function of T lymphocytes?

    Jibu

    Coordinating immune responses or killing infected cells. Different T-cell types perform different roles.

  160. Kadi namba 160

    Swali

    What does an antibody bind?

    Jibu

    A specific antigen. Binding can neutralize a target or mark it for other immune defenses.

  161. Kadi namba 161

    Swali

    What is the purpose of inflammation after tissue injury?

    Jibu

    To contain damage, recruit defenses, and begin repair. Redness, heat, swelling, and pain can accompany it.

  162. Kadi namba 162

    Swali

    Why is a second adaptive response often faster than the first?

    Jibu

    Memory lymphocytes remain after the first exposure. They respond quickly when the same antigen appears again.

  163. Kadi namba 163

    Swali

    What does a phagocyte do?

    Jibu

    It engulfs particles, microbes, or debris. Neutrophils and macrophages are important examples.

  164. Kadi namba 164

    Swali

    How does vaccination support adaptive immunity?

    Jibu

    It safely exposes the immune system to antigen information. This promotes memory without requiring the full disease.

  165. Kadi namba 165

    Swali

    Why is lymphatic fluid return important?

    Jibu

    It prevents excess interstitial fluid from accumulating. Lymphatic vessels return fluid and leaked proteins to blood.

  166. Kadi namba 166

    Swali

    What structures belong to the integumentary system?

    Jibu

    Skin, hair, nails, sweat glands, and sebaceous glands. Together they form the body's outer covering.

  167. Kadi namba 167

    Swali

    What is the epidermis?

    Jibu

    The outer epithelial layer of skin. It is avascular and contains protective keratinized cells.

  168. Kadi namba 168

    Swali

    How does sweating cool the body?

    Jibu

    Evaporation removes heat from the skin. Skin blood-flow changes also help regulate heat loss.

  169. Kadi namba 169

    Swali

    What is a major role of melanin in skin?

    Jibu

    Absorbing some ultraviolet radiation. It also contributes to skin and hair color.

  170. Kadi namba 170

    Swali

    How does skin contribute to sensation?

    Jibu

    Sensory receptors detect touch, pressure, pain, and temperature. Nerves carry that information to the CNS.

  171. Kadi namba 171

    Swali

    What is the dermis?

    Jibu

    The connective-tissue layer beneath the epidermis. It contains vessels, nerves, glands, and hair follicles.

  172. Kadi namba 172

    Swali

    How does skin support vitamin D production?

    Jibu

    Ultraviolet light starts conversion of a skin molecule into a vitamin D precursor. The liver and kidneys complete activation.

  173. Kadi namba 173

    Swali

    Why does a deep skin wound bleed but a shallow epidermal scrape may not?

    Jibu

    Blood vessels are in the dermis, not the epidermis. A wound must reach vascular tissue to damage them.

  174. Kadi namba 174

    Swali

    What is a gamete?

    Jibu

    A haploid reproductive cell. Human sperm and oocytes each carry 23 chromosomes.

  175. Kadi namba 175

    Swali

    What are the testes' two main reproductive functions?

    Jibu

    Producing sperm and secreting testosterone. Sperm develop in seminiferous tubules.

  176. Kadi namba 176

    Swali

    What tube carries sperm from the epididymis toward the ejaculatory duct?

    Jibu

    The ductus, or vas, deferens. Smooth muscle propels sperm during ejaculation.

  177. Kadi namba 177

    Swali

    What is ovulation?

    Jibu

    Release of a secondary oocyte from an ovary. A surge in luteinizing hormone helps trigger it.

  178. Kadi namba 178

    Swali

    Where does fertilization usually occur?

    Jibu

    In a uterine tube. The early embryo then travels toward the uterus.

  179. Kadi namba 179

    Swali

    What are the ovaries' two main reproductive functions?

    Jibu

    Producing oocytes and secreting sex hormones. Estrogen and progesterone help regulate the reproductive cycle.

  180. Kadi namba 180

    Swali

    What is the uterus' main reproductive role?

    Jibu

    Supporting implantation and development of an embryo and fetus. Its muscular wall also contracts during birth.

  181. Kadi namba 181

    Swali

    What causes menstruation when pregnancy does not occur?

    Jibu

    Falling ovarian hormones allow the uterine lining to shed. A new cycle then begins.

  182. Kadi namba 182

    Swali

    How does a sperm cell's structure support its function?

    Jibu

    Its flagellum provides movement, and its head carries DNA plus enzymes used during fertilization. Mitochondria supply energy in the midpiece.

  183. Kadi namba 183

    Swali

    What is the placenta's exchange role?

    Jibu

    It allows gases, nutrients, and wastes to move between maternal and fetal circulations. Their blood normally does not mix directly.

  184. Kadi namba 184

    Swali

    Why is meiosis necessary for sexual reproduction?

    Jibu

    It halves chromosome number in gametes. Fertilization then restores the diploid number.

  185. Kadi namba 185

    Swali

    How do sex hormones regulate reproductive control pathways?

    Jibu

    They usually feed back on the hypothalamus and pituitary. This adjusts release of hormones that act on the gonads.

  186. Kadi namba 186

    Swali

    What does cell theory state?

    Jibu

    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.

  187. Kadi namba 187

    Swali

    What is the defining structural feature of a prokaryotic cell?

    Jibu

    It lacks a membrane-bound nucleus. Its DNA occupies a nucleoid region.

  188. Kadi namba 188

    Swali

    What is the cell membrane's main role?

    Jibu

    Regulating movement between the cell and its environment. Its phospholipid bilayer is selectively permeable.

  189. Kadi namba 189

    Swali

    What is the nucleus' main role?

    Jibu

    Storing most of a eukaryotic cell's DNA. Nuclear pores regulate exchange with the cytoplasm.

  190. Kadi namba 190

    Swali

    Where are proteins assembled?

    Jibu

    At ribosomes. Ribosomes may float in cytosol or attach to rough endoplasmic reticulum.

  191. Kadi namba 191

    Swali

    What distinguishes a eukaryotic cell from a prokaryotic cell?

    Jibu

    A eukaryotic cell has a membrane-bound nucleus and other membrane-bound organelles. Animals, plants, fungi, and protists are eukaryotes.

  192. Kadi namba 192

    Swali

    What is a mitochondrion's main function?

    Jibu

    Producing most cellular ATP through aerobic respiration. Its inner membrane provides a large reaction surface.

  193. Kadi namba 193

    Swali

    What does rough endoplasmic reticulum mainly produce?

    Jibu

    Proteins for secretion, membranes, or organelles. Ribosomes on its surface make the proteins.

  194. Kadi namba 194

    Swali

    Which organelle carries out photosynthesis in plants and algae?

    Jibu

    The chloroplast. It converts light energy into chemical energy stored in organic molecules.

  195. Kadi namba 195

    Swali

    What does the Golgi apparatus do?

    Jibu

    It modifies, sorts, and packages cell products. Vesicles carry those products to their destinations.

  196. Kadi namba 196

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    What is a lysosome's role?

    Jibu

    Digesting worn cell parts and engulfed material. Its enzymes work best in an acidic interior.

  197. Kadi namba 197

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    What are major functions of smooth endoplasmic reticulum?

    Jibu

    Lipid synthesis, detoxification, and calcium storage. Its membrane lacks attached ribosomes.

  198. Kadi namba 198

    Swali

    What does the cytoskeleton provide?

    Jibu

    Cell shape, internal organization, movement, and transport tracks. It is built from protein filaments.

  199. Kadi namba 199

    Swali

    What is diffusion?

    Jibu

    Net movement from higher to lower concentration. It is passive and continues until dynamic equilibrium is reached.

  200. Kadi namba 200

    Swali

    What happens to an animal cell in a strongly hypotonic solution?

    Jibu

    Water enters and the cell swells. Without a cell wall, it may burst.

  201. Kadi namba 201

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    What happens during interphase?

    Jibu

    The cell grows, performs normal functions, and copies its DNA. Interphase precedes mitotic division.

  202. Kadi namba 202

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    What is the result of mitosis followed by cytokinesis?

    Jibu

    Two genetically similar daughter cells. Chromosome number is normally preserved.

  203. Kadi namba 203

    Swali

    What is osmosis?

    Jibu

    Diffusion of water across a selectively permeable membrane. Water moves toward the side with more nonpenetrating solute.

  204. Kadi namba 204

    Swali

    What happens to an animal cell in a hypertonic solution?

    Jibu

    Water leaves and the cell shrinks. The external solution has a higher effective solute concentration.

  205. Kadi namba 205

    Swali

    Why are cells generally small?

    Jibu

    A high surface-area-to-volume ratio supports efficient exchange. Volume grows faster than surface area as a cell enlarges.

  206. Kadi namba 206

    Swali

    What is cytokinesis?

    Jibu

    Division of the cytoplasm. It separates one cell into two after nuclear division.

  207. Kadi namba 207

    Swali

    How does active transport differ from passive transport?

    Jibu

    It uses energy to move substances against a gradient. Passive transport moves down a gradient without direct energy input.

  208. Kadi namba 208

    Swali

    What happens to an animal cell in an isotonic solution?

    Jibu

    There is no net water movement. Water still crosses in both directions at equal rates.

  209. Kadi namba 209

    Swali

    Which structures are typical of plant cells but not animal cells?

    Jibu

    A cellulose cell wall, chloroplasts, and a large central vacuole. Both cell types have membranes, nuclei, and mitochondria.

  210. Kadi namba 210

    Swali

    How do cells contribute to a multicellular organism's organization?

    Jibu

    Specialized cells form tissues, tissues form organs, and organs form systems. Division of labor supports complex functions.

  211. Kadi namba 211

    Swali

    What is DNA's primary biological role?

    Jibu

    Storing hereditary information. Its nucleotide sequence contains instructions used to build functional RNA and proteins.

  212. Kadi namba 212

    Swali

    What are the three parts of a DNA nucleotide?

    Jibu

    A deoxyribose sugar, a phosphate group, and a nitrogenous base. Nucleotides link to form each strand.

  213. Kadi namba 213

    Swali

    Which bases pair in double-stranded DNA?

    Jibu

    Adenine with thymine, and cytosine with guanine. Hydrogen bonds hold complementary strands together.

  214. Kadi namba 214

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    How does RNA differ from DNA?

    Jibu

    RNA usually has ribose, uses uracil instead of thymine, and is usually single-stranded. Several RNA types help express genes.

  215. Kadi namba 215

    Swali

    What is a gene?

    Jibu

    A DNA sequence that contributes to a functional product. The product may be a protein or a functional RNA.

  216. Kadi namba 216

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    What is a chromosome?

    Jibu

    A long DNA molecule packaged with proteins. It contains many genes and other sequences.

  217. Kadi namba 217

    Swali

    What is DNA replication?

    Jibu

    Copying DNA before cell division. Each new DNA molecule contains one old strand and one newly made strand.

  218. Kadi namba 218

    Swali

    What is the usual flow of information from a protein-coding gene?

    Jibu

    DNA to RNA to protein. Transcription makes RNA; translation builds the polypeptide.

  219. Kadi namba 219

    Swali

    What happens during transcription?

    Jibu

    RNA is synthesized from a DNA template. For a protein-coding gene, that RNA functions as or is processed into messenger RNA.

  220. Kadi namba 220

    Swali

    What does messenger RNA carry?

    Jibu

    A copy of coding information from DNA to a ribosome. Its codons specify the amino-acid sequence.

  221. Kadi namba 221

    Swali

    What is a codon?

    Jibu

    A three-nucleotide sequence in mRNA. Most codons specify an amino acid; some signal start or stop.

  222. Kadi namba 222

    Swali

    What is the usual role of the AUG codon?

    Jibu

    It starts translation and specifies methionine. The ribosome uses it to establish the reading frame.

  223. Kadi namba 223

    Swali

    What happens during translation?

    Jibu

    A ribosome reads mRNA and joins amino acids into a polypeptide. Transfer RNAs match codons with amino acids.

    Illustrated anatomy torso surrounded by a cell, DNA helix, molecule, flask, and data plot on a dark blue background.

    kadi 446

    ATI TEAS 7 Science Flashcards: A&P, Biology, Chemistry & Scientific Reasoning

    Soma fungu hili bila malipo

    Nibomo itafunguka ili uanze kusoma.

  224. Kadi namba 224

    Swali

    What is transfer RNA's role in protein synthesis?

    Jibu

    It carries an amino acid and matches its anticodon to an mRNA codon. This places the correct amino acid in sequence.

  225. Kadi namba 225

    Swali

    What is an anticodon?

    Jibu

    A three-base sequence on tRNA complementary to an mRNA codon. Pairing helps decode the message.

  226. Kadi namba 226

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    What is a mutation?

    Jibu

    A change in a DNA sequence. Its effect may be harmful, neutral, or beneficial depending on location and context.

  227. Kadi namba 227

    Swali

    Why can a one-base insertion in a coding sequence have a large effect?

    Jibu

    It can shift the reading frame. Every downstream codon may change until a stop signal appears.

  228. Kadi namba 228

    Swali

    Why can changing one amino acid alter a protein's function?

    Jibu

    Amino-acid sequence helps determine folding and shape. Shape controls many protein interactions.

  229. Kadi namba 229

    Swali

    What is ribosomal RNA's role in protein synthesis?

    Jibu

    It forms the structural and catalytic core of ribosomes. Ribosomal RNA helps align translation components and catalyzes peptide-bond formation.

  230. Kadi namba 230

    Swali

    Why can different cell types contain the same DNA but perform different jobs?

    Jibu

    They express different sets of genes. Different proteins give cells different structures and functions.

  231. Kadi namba 231

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    Which mutation can be passed to offspring?

    Jibu

    A mutation present in a gamete-forming lineage. A mutation limited to ordinary body cells is not inherited through reproduction.

  232. Kadi namba 232

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    What is an allele?

    Jibu

    An alternative version of a gene. Diploid individuals usually carry two alleles for each autosomal gene.

  233. Kadi namba 233

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    What is genotype?

    Jibu

    An organism's allele combination for a gene or set of genes. Genotype contributes to phenotype.

  234. Kadi namba 234

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    What does homozygous mean?

    Jibu

    Having two identical alleles for a gene. Examples include AA and aa.

  235. Kadi namba 235

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    What makes an allele dominant in a simple Mendelian trait?

    Jibu

    One copy is enough for its phenotype to appear in a heterozygote. Dominant does not mean common or beneficial.

  236. Kadi namba 236

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    What does Mendel's law of segregation describe?

    Jibu

    The two alleles for a gene separate during gamete formation. Each gamete receives one allele.

  237. Kadi namba 237

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    What is phenotype?

    Jibu

    An observable trait or characteristic. It can reflect genotype, environment, and their interaction.

  238. Kadi namba 238

    Swali

    What does heterozygous mean?

    Jibu

    Having two different alleles for a gene. An example is Aa.

  239. Kadi namba 239

    Swali

    When does a recessive phenotype usually appear in a simple autosomal trait?

    Jibu

    When both alleles are recessive. A heterozygote carries the allele without showing that phenotype.

  240. Kadi namba 240

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    When does independent assortment apply most clearly?

    Jibu

    When genes are on different chromosomes or far apart on the same chromosome. Their allele pairs enter gametes independently.

  241. Kadi namba 241

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    What does a Punnett square predict?

    Jibu

    Expected offspring genotype probabilities from specified parental gametes. It does not guarantee outcomes in a small family.

  242. Kadi namba 242

    Swali

    For Aa × Aa, what is the chance of an aa offspring?

    Jibu

    One fourth, or 25%. The genotype ratio is expected to be 1 AA : 2 Aa : 1 aa.

  243. Kadi namba 243

    Swali

    For Aa × Aa with complete dominance, what phenotypic ratio is expected?

    Jibu

    Three dominant-phenotype offspring to one recessive-phenotype offspring. This is a probability across many offspring.

  244. Kadi namba 244

    Swali

    How can a test cross reveal the genotype behind a dominant phenotype?

    Jibu

    Cross the individual with a homozygous recessive partner. Recessive offspring show that the unknown parent carried a recessive allele.

  245. Kadi namba 245

    Swali

    What happens in incomplete dominance?

    Jibu

    A heterozygote has an intermediate phenotype. Neither allele fully masks the other.

  246. Kadi namba 246

    Swali

    How is the probability of two independent genetic events both occurring found?

    Jibu

    Multiply their individual probabilities. This is the product rule.

  247. Kadi namba 247

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    What does a pedigree show?

    Jibu

    How a trait appears across generations of a family. Its pattern can suggest a mode of inheritance.

  248. Kadi namba 248

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    Why can two parents have offspring ratios that differ from a Punnett-square expectation?

    Jibu

    Each fertilization is a chance event. Expected ratios become more apparent with larger numbers of offspring.

  249. Kadi namba 249

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    What happens in codominance?

    Jibu

    Both alleles are distinctly expressed in a heterozygote. The AB blood type is a common example.

  250. Kadi namba 250

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    What are major roles of carbohydrates?

    Jibu

    Providing quick energy, storing energy, and forming some structures. Monosaccharides are their basic building blocks.

  251. Kadi namba 251

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    What is a monomer?

    Jibu

    A small building block that can join with others to form a larger molecule. Glucose, amino acids, and nucleotides are examples in different classes.

  252. Kadi namba 252

    Swali

    What happens in a dehydration-synthesis reaction?

    Jibu

    Monomers join while water is removed. The reaction builds a larger biological molecule.

  253. Kadi namba 253

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    What does an enzyme do?

    Jibu

    It lowers activation energy and speeds a reaction without being consumed. Its shape helps it bind specific substrates.

  254. Kadi namba 254

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    What are major roles of lipids?

    Jibu

    Long-term energy storage, membranes, insulation, and signaling. Lipids are mostly nonpolar and do not mix well with water.

  255. Kadi namba 255

    Swali

    What does it mean for a protein to denature?

    Jibu

    Its normal shape is disrupted. Heat, extreme pH, or chemicals can reduce its function.

  256. Kadi namba 256

    Swali

    What happens during hydrolysis?

    Jibu

    Water is used to split a larger molecule into smaller units. Digestion often uses hydrolysis reactions.

  257. Kadi namba 257

    Swali

    Why do phospholipids form bilayers in water?

    Jibu

    Their hydrophilic heads interact with water while hydrophobic tails turn inward. This arrangement forms cell-membrane structure.

  258. Kadi namba 258

    Swali

    What are proteins built from?

    Jibu

    Amino acids linked by peptide bonds. Their folded shapes support enzymes, transport, signaling, structure, and movement.

  259. Kadi namba 259

    Swali

    How do starch and glycogen compare?

    Jibu

    Both store glucose; plants use starch and animals use glycogen. Their branching patterns differ.

  260. Kadi namba 260

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    How do saturated and unsaturated fatty acids differ?

    Jibu

    Saturated fatty acids lack carbon-carbon double bonds; unsaturated ones have one or more. Double bonds often introduce bends.

  261. Kadi namba 261

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    What immediate energy-carrying molecule powers many cell processes?

    Jibu

    ATP. Energy released from nutrients can be transferred into ATP's phosphate bonds.

  262. Kadi namba 262

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    What are nucleic acids built from?

    Jibu

    Nucleotides. DNA stores hereditary information, while RNA performs several roles in gene expression.

  263. Kadi namba 263

    Swali

    Which elements are common in all four major biological macromolecule classes?

    Jibu

    Carbon, hydrogen, and oxygen. Nitrogen and phosphorus occur prominently in some classes.

  264. Kadi namba 264

    Swali

    Why is three-dimensional shape important for macromolecules?

    Jibu

    Shape determines many interactions and functions. A changed shape can prevent a molecule from binding its target.

  265. Kadi namba 265

    Swali

    What are triglycerides built from?

    Jibu

    One glycerol molecule and three fatty acids. They join through ester bonds to form a common energy-storage lipid.

  266. Kadi namba 266

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    What is a pathogen?

    Jibu

    An agent capable of causing disease. Not every microorganism is pathogenic.

  267. Kadi namba 267

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    What type of cell is a bacterium?

    Jibu

    A prokaryotic cell. Bacteria usually reproduce by binary fission.

  268. Kadi namba 268

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    What cell type do fungi have?

    Jibu

    Eukaryotic cells. Some fungi are unicellular yeasts, while others form multicellular filaments.

  269. Kadi namba 269

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    What does disease transmission describe?

    Jibu

    How an infectious agent moves to a susceptible host. Routes include contact, droplets, airborne spread, food, water, and vectors.

  270. Kadi namba 270

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    What is a biological vector?

    Jibu

    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.

  271. Kadi namba 271

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    Why are viruses dependent on host cells?

    Jibu

    They lack the complete machinery for reproduction and metabolism. They use host components to make new virus particles.

  272. Kadi namba 272

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    What is a protist?

    Jibu

    A diverse eukaryote that is not classified as an animal, plant, or fungus. Some protists cause disease, while many do not.

  273. Kadi namba 273

    Swali

    Why do antibiotics not treat viral infections?

    Jibu

    They target bacterial structures or processes that viruses lack. Antiviral drugs use different targets.

  274. Kadi namba 274

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    How can normal microbiota protect a host?

    Jibu

    They occupy space and use resources that pathogens might otherwise exploit. Some also support digestion or immune development.

  275. Kadi namba 275

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    How does sterilization differ from disinfection?

    Jibu

    Sterilization destroys or removes all microbial life, including resistant forms; disinfection reduces pathogens on objects. The required method depends on use.

  276. Kadi namba 276

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    How do infection and disease differ?

    Jibu

    Infection means an agent is established in a host; disease means normal function is impaired and signs or symptoms occur. Infection may be asymptomatic.

  277. Kadi namba 277

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    How can breaking a transmission route reduce infectious disease?

    Jibu

    It interrupts the chain connecting a source with a susceptible host. Hand hygiene, clean water, ventilation, and vector control target different links.

  278. Kadi namba 278

    Swali

    What is an atom?

    Jibu

    The smallest unit of an element that retains that element's chemical identity. Atoms contain a nucleus surrounded by electrons.

  279. Kadi namba 279

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    What charge and location does an electron have?

    Jibu

    Negative charge in the electron cloud around the nucleus. Electrons drive most chemical bonding.

  280. Kadi namba 280

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    Why are valence electrons important?

    Jibu

    They participate most directly in bonding and reactions. Their arrangement helps predict chemical behavior.

  281. Kadi namba 281

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    What do elements in the same periodic-table group often share?

    Jibu

    Similar valence-electron patterns and chemical properties. A group is a vertical column.

  282. Kadi namba 282

    Swali

    What is an ion?

    Jibu

    An atom or group of atoms with a net electric charge. Its total numbers of protons and electrons are unequal.

  283. Kadi namba 283

    Swali

    What charge and location does a proton have?

    Jibu

    Positive charge in the nucleus. The number of protons determines the element.

  284. Kadi namba 284

    Swali

    What does an element's atomic number equal?

    Jibu

    Its number of protons. A neutral atom has the same number of electrons.

  285. Kadi namba 285

    Swali

    How does a neutral atom form a cation?

    Jibu

    By losing one or more electrons. It has more protons than electrons and a positive charge.

  286. Kadi namba 286

    Swali

    An atom has 8 protons. How many electrons does it have if it is neutral?

    Jibu

    Eight electrons. Neutral atoms have equal positive and negative charges.

  287. Kadi namba 287

    Swali

    What charge and location does a neutron have?

    Jibu

    No electric charge, in the nucleus. Neutron number can vary among isotopes of an element.

  288. Kadi namba 288

    Swali

    What does mass number equal?

    Jibu

    Protons plus neutrons in one atom. It is a whole number for a specific isotope.

  289. Kadi namba 289

    Swali

    How does a neutral atom form an anion?

    Jibu

    By gaining one or more electrons. It has more electrons than protons and a negative charge.

  290. Kadi namba 290

    Swali

    What does a period represent on the periodic table?

    Jibu

    A horizontal row. Moving across a period changes proton number one element at a time.

  291. Kadi namba 291

    Swali

    What are isotopes?

    Jibu

    Atoms of the same element with different numbers of neutrons. They have the same atomic number but different mass numbers.

  292. Kadi namba 292

    Swali

    What is matter?

    Jibu

    Anything that has mass and occupies space. Solids, liquids, gases, and plasma are forms of matter.

  293. Kadi namba 293

    Swali

    What distinguishes a solid from a liquid or gas?

    Jibu

    A solid has a definite shape and volume. Its particles vibrate around relatively fixed positions.

  294. Kadi namba 294

    Swali

    What is a physical change?

    Jibu

    A change in form or state without changing chemical identity. Melting and cutting are examples.

  295. Kadi namba 295

    Swali

    What is a physical property?

    Jibu

    A characteristic observed without changing a substance's identity. Density, color, and melting point are examples.

  296. Kadi namba 296

    Swali

    How does an element differ from a compound?

    Jibu

    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.

  297. Kadi namba 297

    Swali

    What distinguishes a liquid?

    Jibu

    It has a definite volume but takes the shape of its container. Its particles remain close while moving past one another.

  298. Kadi namba 298

    Swali

    What is a chemical change?

    Jibu

    A process that forms one or more substances with new chemical identities. Bond rearrangement occurs.

  299. Kadi namba 299

    Swali

    What is a chemical property?

    Jibu

    A substance's ability to undergo a particular chemical change. Flammability and reactivity with acid are examples.

  300. Kadi namba 300

    Swali

    Which phase changes connect solids and liquids?

    Jibu

    Melting changes a solid to a liquid; freezing changes a liquid to a solid. These are opposite physical changes.

  301. Kadi namba 301

    Swali

    How does a pure substance differ from a mixture?

    Jibu

    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.

  302. Kadi namba 302

    Swali

    What distinguishes a gas?

    Jibu

    It has neither a definite shape nor a definite volume. It expands to fill its container.

  303. Kadi namba 303

    Swali

    What is the formula for density?

    Jibu

    Density = mass ÷ volume. Density is an intensive property.

  304. Kadi namba 304

    Swali

    Which phase changes connect liquids and gases?

    Jibu

    Vaporization changes a liquid to a gas; condensation changes a gas to a liquid. Evaporation is vaporization at a liquid's surface.

  305. Kadi namba 305

    Swali

    What is a mixture?

    Jibu

    Two or more substances physically combined in variable proportions. Its components retain their chemical identities.

  306. Kadi namba 306

    Swali

    How do intensive and extensive properties differ?

    Jibu

    Intensive properties do not depend on sample amount; extensive properties do. Density and temperature are intensive, while mass and volume are extensive.

  307. Kadi namba 307

    Swali

    A 20 g sample occupies 5 mL. What is its density?

    Jibu

    4 g/mL. Divide 20 g by 5 mL.

  308. Kadi namba 308

    Swali

    Which phase changes connect solids and gases directly?

    Jibu

    Sublimation changes a solid to a gas; deposition changes a gas to a solid. Neither transition passes through the liquid state.

  309. Kadi namba 309

    Swali

    How do homogeneous and heterogeneous mixtures differ?

    Jibu

    A homogeneous mixture is uniform throughout; a heterogeneous mixture is not. A solution is homogeneous.

  310. Kadi namba 310

    Swali

    Where are reactants and products written in a chemical equation?

    Jibu

    Reactants are on the left; products are on the right. The arrow shows the direction represented.

  311. Kadi namba 311

    Swali

    Why must a chemical equation be balanced?

    Jibu

    Atoms are conserved in ordinary chemical reactions. Each element must have the same atom count on both sides.

  312. Kadi namba 312

    Swali

    What does a coefficient in a chemical equation change?

    Jibu

    The number of whole particles or moles represented. It multiplies every atom in the following formula.

  313. Kadi namba 313

    Swali

    Why should subscripts not be changed when balancing an equation?

    Jibu

    Changing a subscript changes the substance's identity. Balancing changes coefficients only.

  314. Kadi namba 314

    Swali

    What coefficients balance H₂ + O₂ → H₂O?

    Jibu

    2, 1, 2: 2H₂ + O₂ → 2H₂O. Both sides then contain four hydrogen atoms and two oxygen atoms.

  315. Kadi namba 315

    Swali

    What pattern defines a synthesis reaction?

    Jibu

    Two or more reactants form a more complex product. A general pattern is A + B → AB.

  316. Kadi namba 316

    Swali

    What are typical products when a hydrocarbon burns completely in oxygen?

    Jibu

    Carbon dioxide and water. Incomplete combustion can produce carbon monoxide or carbon.

  317. Kadi namba 317

    Swali

    What is the net ionic equation for a typical strong acid–strong base neutralization?

    Jibu

    H⁺(aq) + OH⁻(aq) → H₂O(l). The remaining ions are spectators and do not appear in the net ionic equation.

  318. Kadi namba 318

    Swali

    What is a precipitate?

    Jibu

    An insoluble solid that forms from substances in solution. Its appearance can signal a chemical reaction.

  319. Kadi namba 319

    Swali

    What pattern defines a decomposition reaction?

    Jibu

    One compound breaks into simpler products. A general pattern is AB → A + B.

  320. Kadi namba 320

    Swali

    What is an exothermic reaction?

    Jibu

    A reaction that releases heat to the surroundings. The surroundings often warm.

  321. Kadi namba 321

    Swali

    What occurs in an oxidation-reduction reaction?

    Jibu

    Electrons transfer or atoms change oxidation state. Oxidation is electron loss; reduction is electron gain.

  322. Kadi namba 322

    Swali

    What is activation energy?

    Jibu

    The minimum energy barrier reactants must overcome to react. Catalysts lower this barrier.

  323. Kadi namba 323

    Swali

    Which observations can provide evidence of a chemical reaction?

    Jibu

    Gas formation, a precipitate, sustained color change, light, or temperature change. No single sign proves a reaction without context.

  324. Kadi namba 324

    Swali

    What is an endothermic reaction?

    Jibu

    A reaction that absorbs heat from the surroundings. The surroundings may cool.

  325. Kadi namba 325

    Swali

    Why does raising temperature usually speed a reaction?

    Jibu

    Particles collide more often and with greater energy. More collisions overcome activation energy.

  326. Kadi namba 326

    Swali

    Why can higher reactant concentration increase reaction rate?

    Jibu

    More reactant particles occupy a given volume. This raises collision frequency.

  327. Kadi namba 327

    Swali

    Why does powdered solid often react faster than one large piece?

    Jibu

    Powder exposes more surface area. More particles are available for collisions.

  328. Kadi namba 328

    Swali

    How does a catalyst speed a reaction?

    Jibu

    It provides a pathway with lower activation energy. The catalyst is regenerated rather than consumed overall.

  329. Kadi namba 329

    Swali

    How can increasing pressure affect a reaction between gases?

    Jibu

    It can increase rate by bringing gas particles closer together. Collision frequency rises when volume falls.

  330. Kadi namba 330

    Swali

    What does a reaction inhibitor do?

    Jibu

    It slows a reaction. It may block a pathway, interfere with a catalyst, or remove reactive intermediates.

  331. Kadi namba 331

    Swali

    Why can very high temperature slow an enzyme-catalyzed reaction?

    Jibu

    The enzyme can denature and lose its active shape. Moderate warming helps only within the enzyme's stable range.

  332. Kadi namba 332

    Swali

    What is dynamic equilibrium?

    Jibu

    Forward and reverse reactions continue at equal rates. Concentrations remain constant even though particles still react.

  333. Kadi namba 333

    Swali

    Does a catalyst change the final equilibrium amounts?

    Jibu

    No. It speeds forward and reverse reactions, so equilibrium is reached sooner without changing its position.

  334. Kadi namba 334

    Swali

    At equilibrium, what usually happens when the concentration of a dissolved or gaseous reactant increases?

    Jibu

    The system shifts toward consuming some added reactant. It forms more product until a new equilibrium is reached.

  335. Kadi namba 335

    Swali

    What is a solution?

    Jibu

    A homogeneous mixture. Its components are uniformly distributed at the molecular or ionic level.

  336. Kadi namba 336

    Swali

    How do solute and solvent differ?

    Jibu

    The solute is dissolved; the solvent is the dissolving medium. The solvent is often present in greater amount.

  337. Kadi namba 337

    Swali

    What does aqueous mean in chemistry?

    Jibu

    Dissolved in water. The symbol (aq) marks an aqueous species in an equation.

  338. Kadi namba 338

    Swali

    What does concentration describe?

    Jibu

    The amount of solute in a given amount of solution or solvent. Different units express it in different ways.

  339. Kadi namba 339

    Swali

    What is molarity?

    Jibu

    Moles of solute per liter of solution. Its unit is mol/L, written M.

  340. Kadi namba 340

    Swali

    What is the molarity of 0.50 mol solute in 2.0 L of solution?

    Jibu

    0.25 M. Divide 0.50 mol by 2.0 L.

  341. Kadi namba 341

    Swali

    What stays constant when water is added to dilute a solution without reaction?

    Jibu

    The moles of solute. Volume increases and concentration decreases.

  342. Kadi namba 342

    Swali

    Which equation relates concentration and volume before and after a dilution?

    Jibu

    M₁V₁ = M₂V₂. It follows from conserving the amount of solute.

  343. Kadi namba 343

    Swali

    What is solubility?

    Jibu

    The maximum concentration of a solute that can be achieved in a solution at equilibrium under specified conditions. Temperature and the substances involved matter.

  344. Kadi namba 344

    Swali

    What is a saturated solution?

    Jibu

    A solution holding the maximum dissolved solute at those conditions. Extra solute remains undissolved at equilibrium.

  345. Kadi namba 345

    Swali

    What is an electrolyte?

    Jibu

    A substance that produces mobile ions in solution and conducts electricity. Soluble ionic compounds are common examples.

  346. Kadi namba 346

    Swali

    What does 'like dissolves like' predict?

    Jibu

    Substances with similar polarity tend to mix well. Polar solvents favor polar or ionic solutes; nonpolar solvents favor nonpolar solutes.

  347. Kadi namba 347

    Swali

    Does heating always increase solubility?

    Jibu

    No. Many solids become more soluble in water, but gases usually become less soluble as temperature rises.

  348. Kadi namba 348

    Swali

    What is an unsaturated solution?

    Jibu

    A solution that can dissolve more solute at the stated conditions. It is below the solubility limit.

  349. Kadi namba 349

    Swali

    What does a Brønsted-Lowry acid donate?

    Jibu

    A proton, H⁺. In water, acid behavior increases hydronium-ion concentration.

  350. Kadi namba 350

    Swali

    What does pH describe?

    Jibu

    The hydronium-ion concentration on a logarithmic scale. Lower pH means higher hydronium concentration.

  351. Kadi namba 351

    Swali

    At 25 °C, what pH range is acidic?

    Jibu

    Below 7. A neutral aqueous solution is pH 7 at this temperature.

  352. Kadi namba 352

    Swali

    How does hydronium concentration change when pH drops by 1 unit?

    Jibu

    It increases tenfold. The pH scale is logarithmic.

  353. Kadi namba 353

    Swali

    What does a Brønsted-Lowry base accept?

    Jibu

    A proton, H⁺. Many bases in water also increase hydroxide-ion concentration.

  354. Kadi namba 354

    Swali

    At 25 °C, what is the relationship between pH and pOH?

    Jibu

    pH + pOH = 14. pOH is the negative base-10 logarithm of hydroxide-ion concentration; this relation applies to aqueous solutions at 25 °C.

  355. Kadi namba 355

    Swali

    At 25 °C, what pH range is basic?

    Jibu

    Above 7. Basic solutions have less hydronium and more hydroxide than neutral water.

  356. Kadi namba 356

    Swali

    What are typical products of a strong acid reacting with a strong base?

    Jibu

    Water and an ionic salt. Hydrogen ions and hydroxide ions combine to form water.

  357. Kadi namba 357

    Swali

    What does strong mean for an acid or base?

    Jibu

    It produces its characteristic ions essentially completely in water. Strong acids ionize; soluble ionic strong bases dissociate. Strength is separate from concentration.

  358. Kadi namba 358

    Swali

    What does a buffer do?

    Jibu

    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⁻.

  359. Kadi namba 359

    Swali

    How does an acid-base indicator work?

    Jibu

    Its color depends on pH. The change occurs over a characteristic pH range.

  360. Kadi namba 360

    Swali

    A solution has pH 9 at 25 °C. What is its pOH?

    Jibu

    5. Subtract the pH from 14.

  361. Kadi namba 361

    Swali

    How does a concentrated weak acid differ from a dilute strong acid?

    Jibu

    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.

  362. Kadi namba 362

    Swali

    What is the SI base unit of length?

    Jibu

    The meter (m). Centimeters and millimeters are decimal subdivisions of a meter.

  363. Kadi namba 363

    Swali

    Which tool directly measures mass in a laboratory?

    Jibu

    A balance. A spring scale measures force, often reported as weight.

  364. Kadi namba 364

    Swali

    What is the SI base unit of mass?

    Jibu

    The kilogram (kg). Laboratory mass is also commonly reported in grams.

  365. Kadi namba 365

    Swali

    A student needs to measure about 35 mL of liquid and can choose a beaker or graduated cylinder. Which should they use?

    Jibu

    A graduated cylinder. Read the scale at eye level.

  366. Kadi namba 366

    Swali

    What is the SI base unit of time?

    Jibu

    The second (s). Minutes and hours are accepted for many everyday uses.

  367. Kadi namba 367

    Swali

    Where should the volume of a clear water-based liquid be read in a graduated cylinder?

    Jibu

    At the bottom of the meniscus. Keep your eye level with the liquid surface.

  368. Kadi namba 368

    Swali

    What is the SI base unit of thermodynamic temperature?

    Jibu

    The kelvin (K). Degrees Celsius are widely used for laboratory and body temperatures.

  369. Kadi namba 369

    Swali

    Which tool measures temperature?

    Jibu

    A thermometer. Its range and resolution should match the task.

  370. Kadi namba 370

    Swali

    What factor does the metric prefix kilo- represent?

    Jibu

    One thousand, or 10³. One kilometer equals 1,000 meters.

  371. Kadi namba 371

    Swali

    A ruler's smallest marking is 1 mm. To what place should a careful analog reading usually be estimated?

    Jibu

    One place beyond the smallest marking, when the scale allows it. The final digit is uncertain.

  372. Kadi namba 372

    Swali

    What is measurement accuracy?

    Jibu

    Closeness to an accepted or true value. A systematic error can make precise measurements inaccurate.

  373. Kadi namba 373

    Swali

    How do mass and weight differ?

    Jibu

    Mass is the amount of matter; weight is gravitational force on that mass. Mass stays constant when gravity changes, but weight does not.

  374. Kadi namba 374

    Swali

    What factor does the metric prefix milli- represent?

    Jibu

    One thousandth, or 10⁻³. One milliliter is 0.001 liter.

  375. Kadi namba 375

    Swali

    How can the volume of an irregular solid be measured with water?

    Jibu

    Use water displacement. Subtract the initial water volume from the final volume after submerging the object.

  376. Kadi namba 376

    Swali

    What is measurement precision?

    Jibu

    Closeness of repeated measurements to one another. Precise results can still be consistently wrong.

  377. Kadi namba 377

    Swali

    What is an instrument's resolution?

    Jibu

    The smallest change it can meaningfully display or distinguish. Higher resolution does not automatically guarantee accuracy.

  378. Kadi namba 378

    Swali

    How many centimeters are in 2.5 meters?

    Jibu

    2.5 × 10² cm (250 cm). Multiply meters by the exact conversion factor 100 cm/m.

  379. Kadi namba 379

    Swali

    Why must a numerical measurement include a unit?

    Jibu

    The unit identifies the quantity's scale. A bare number is ambiguous and cannot be compared reliably.

  380. Kadi namba 380

    Swali

    What is a scientific observation?

    Jibu

    Information recorded with senses or instruments. It should be distinguished from an explanation of what was observed.

  381. Kadi namba 381

    Swali

    What makes a hypothesis scientifically useful?

    Jibu

    It is testable and falsifiable. Evidence must be able to count against it.

  382. Kadi namba 382

    Swali

    What is a scientific theory?

    Jibu

    A broad, well-supported explanation of natural phenomena. It is not a casual guess and can be revised with new evidence.

  383. Kadi namba 383

    Swali

    Which claim is falsifiable: 'No possible observation could count against this treatment's effectiveness' or 'This treatment lowers mean temperature within one hour'?

    Jibu

    The claim that the treatment lowers mean temperature within one hour. An observation could count against it, so evidence can test it.

  384. Kadi namba 384

    Swali

    What is an inference?

    Jibu

    A logical interpretation based on observations and prior knowledge. It goes beyond the raw measurement.

  385. Kadi namba 385

    Swali

    How does a prediction relate to a hypothesis?

    Jibu

    It states an expected result if the hypothesis is correct. Experiments compare observed results with that expectation.

  386. Kadi namba 386

    Swali

    How does a scientific law differ from a scientific theory?

    Jibu

    A law describes a consistent pattern; a theory explains how or why patterns occur. One does not mature into the other.

  387. Kadi namba 387

    Swali

    What does reliability mean for a measurement or procedure?

    Jibu

    It produces consistent results under the same conditions. Repetition helps assess reliability.

  388. Kadi namba 388

    Swali

    What does a correlation show?

    Jibu

    Two variables change together in a patterned way. Correlation alone does not establish that one causes the other.

  389. Kadi namba 389

    Swali

    What is bias in scientific work?

    Jibu

    A systematic influence that pushes observations, selection, or interpretation in one direction. Good design tries to prevent or measure it.

  390. Kadi namba 390

    Swali

    What is the purpose of scientific peer review?

    Jibu

    Independent experts evaluate methods, reasoning, and reporting before publication. It improves scrutiny but does not guarantee truth.

  391. Kadi namba 391

    Swali

    What does validity ask about a study or measurement?

    Jibu

    Whether it measures or tests what it claims to measure or test. Consistency alone does not ensure validity.

  392. Kadi namba 392

    Swali

    What evidence most strengthens a causal claim?

    Jibu

    A well-controlled experiment that manipulates the suspected cause. Random assignment reduces confounding, while independent replication tests whether the result holds with new data.

  393. Kadi namba 393

    Swali

    What is a primary scientific source?

    Jibu

    A report of original methods, data, and results. A review article synthesizes many primary studies.

  394. Kadi namba 394

    Swali

    How should an unexpected outlier be handled?

    Jibu

    Investigate and report it rather than deleting it automatically. Exclusion needs a documented scientific reason.

  395. Kadi namba 395

    Swali

    What is a confounding variable?

    Jibu

    An outside factor related to both the suspected cause and the outcome. It can create a misleading association.

  396. Kadi namba 396

    Swali

    Why should a sample represent the population of interest?

    Jibu

    Results generalize poorly when important groups are missing or overrepresented. Sampling method matters as much as size.

  397. Kadi namba 397

    Swali

    What is a scientific model?

    Jibu

    A simplified representation used to explain or predict a system. A model is useful within its assumptions and limits.

  398. Kadi namba 398

    Swali

    Why should measurements report uncertainty or reasonable precision?

    Jibu

    Every measurement has limits. Reporting more digits than the method supports creates false precision.

  399. Kadi namba 399

    Swali

    If results match a prediction once, what is the safest conclusion?

    Jibu

    The results support the hypothesis under those conditions. One result does not prove the hypothesis in every setting.

  400. Kadi namba 400

    Swali

    What is a direct relationship between two variables?

    Jibu

    As one increases, the other tends to increase; as one decreases, the other tends to decrease. The relationship need not be perfectly linear.

  401. Kadi namba 401

    Swali

    Which variable is usually placed on the x-axis of an experimental graph?

    Jibu

    The independent variable. It is the factor selected or changed by the investigator.

  402. Kadi namba 402

    Swali

    What does the slope of a straight-line graph represent?

    Jibu

    Change in y divided by change in x. It is the response rate per unit change in the other variable.

  403. Kadi namba 403

    Swali

    A line rises 12 units in y while x rises 3 units. What is its slope?

    Jibu

    4 units of y per unit of x. Divide 12 by 3.

  404. Kadi namba 404

    Swali

    What is an inverse relationship?

    Jibu

    As one variable increases, the other tends to decrease. Their product is constant only in a strictly inverse proportion.

  405. Kadi namba 405

    Swali

    Which variable is usually placed on the y-axis of an experimental graph?

    Jibu

    The dependent variable. It is the measured response.

  406. Kadi namba 406

    Swali

    What does a plateau on a response graph indicate?

    Jibu

    The measured response has stopped changing much despite further x increases. A limiting factor may have been reached.

  407. Kadi namba 407

    Swali

    What is interpolation?

    Jibu

    Estimating a value within the range of measured data. It is generally safer than extrapolating beyond that range.

  408. Kadi namba 408

    Swali

    What pattern suggests no relationship between two plotted variables?

    Jibu

    The response shows no consistent change as the other variable changes. Points may scatter without a trend.

  409. Kadi namba 409

    Swali

    Before comparing values in a data table, what should you check?

    Jibu

    Headings, units, and conditions. Numbers from different measures or scales cannot be compared directly.

  410. Kadi namba 410

    Swali

    If 3 samples require 12 mL total, how much is needed for 5 equal samples?

    Jibu

    20 mL. The rate is 4 mL per sample, so multiply by 5.

  411. Kadi namba 411

    Swali

    How is the arithmetic mean calculated?

    Jibu

    Add all values and divide by the number of values. A large outlier can shift the mean.

  412. Kadi namba 412

    Swali

    Why is extrapolation uncertain?

    Jibu

    It assumes the observed trend continues outside measured conditions. The relationship may change beyond the data range.

  413. Kadi namba 413

    Swali

    A culture grows from 20 to 50 cells in 6 hours. What is the average growth rate?

    Jibu

    5 cells per hour. The change is 30 cells divided by 6 hours.

  414. Kadi namba 414

    Swali

    A measurement rises from 40 to 50. What is the percent increase?

    Jibu

    25%. The increase is 10, and 10 ÷ 40 × 100 = 25%.

  415. Kadi namba 415

    Swali

    When can the median describe a typical value better than the mean?

    Jibu

    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.

  416. Kadi namba 416

    Swali

    How do quantitative and qualitative data differ?

    Jibu

    Quantitative data are numerical; qualitative data describe categories or qualities. Both can answer scientific questions.

  417. Kadi namba 417

    Swali

    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?

    Jibu

    6. The observed rate is 2 response units per dose unit, so interpolation at dose 3 gives 6.

  418. Kadi namba 418

    Swali

    How can a graph reveal a nonlinear relationship?

    Jibu

    The points follow a curve rather than a straight line. The rate of change varies across the x-range.

  419. Kadi namba 419

    Swali

    What is the range of a data set?

    Jibu

    Maximum minus minimum. It describes total spread but ignores the distribution between the endpoints.

  420. Kadi namba 420

    Swali

    What makes a scientific research question testable?

    Jibu

    It identifies measurable variables or observable outcomes. The needed data must be obtainable.

  421. Kadi namba 421

    Swali

    In an experiment, what is the independent variable?

    Jibu

    The factor deliberately changed or assigned by the investigator. In a simple one-factor experiment, changing one independent variable helps isolate its effect.

  422. Kadi namba 422

    Swali

    What should a hypothesis connect?

    Jibu

    A proposed explanation with a measurable outcome. It should lead to a prediction that evidence can challenge.

  423. Kadi namba 423

    Swali

    What is a controlled variable, or constant?

    Jibu

    A condition kept the same across groups. Holding it constant prevents it from explaining outcome differences.

  424. Kadi namba 424

    Swali

    What is the purpose of a control group?

    Jibu

    It provides a comparison without the experimental treatment. Differences can then be attributed more confidently to the treatment.

  425. Kadi namba 425

    Swali

    In an experiment, what is the dependent variable?

    Jibu

    The measured response. It may change because of the independent variable.

  426. Kadi namba 426

    Swali

    What form can a useful experimental prediction take?

    Jibu

    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.

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    What does a positive control demonstrate?

    Jibu

    That the setup can produce a known response. If it fails, the test system may be defective.

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    Why randomly assign subjects to experimental groups?

    Jibu

    To distribute known and unknown differences more evenly. This reduces selection bias and confounding.

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    How can blinding reduce bias?

    Jibu

    It keeps participants, observers, or both unaware of treatment assignments. Expectations are less likely to affect behavior or measurement.

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    What is a placebo?

    Jibu

    An inactive treatment designed to resemble the experimental treatment. It helps separate treatment effects from expectation effects.

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    What does a negative control demonstrate?

    Jibu

    What happens when the tested cause is absent. An unexpected response may reveal contamination or another source.

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    Why does a larger sample often improve a study?

    Jibu

    It reduces the influence of chance variation and supports more stable estimates. It cannot repair a biased sampling method.

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    Why repeat trials within an experiment?

    Jibu

    To estimate variability and check consistency. One unusual trial then has less influence.

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    Why must an experimental procedure be detailed and standardized?

    Jibu

    So groups are treated consistently and others can reproduce the work. Uncontrolled procedural differences create alternative explanations.

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    Why calibrate a measuring instrument before collecting data?

    Jibu

    To compare its readings with a known standard and reduce systematic error. Calibration improves confidence in accuracy.

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    What is an operational definition?

    Jibu

    A precise statement of how a variable is measured or manipulated. It turns an abstract concept into a repeatable procedure.

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    How does independent replication differ from repeated trials?

    Jibu

    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.

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    Why should raw data be recorded before interpretation?

    Jibu

    It preserves the observations separately from conclusions. Others can check calculations and reasoning.

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    What should a scientific conclusion do?

    Jibu

    Answer the research question using the data and acknowledge limits. It should not claim more than the design supports.

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    What should happen when data do not support a hypothesis?

    Jibu

    Revise or reject the hypothesis and consider new tests. Data should not be altered to preserve the original idea.

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    What is a study limitation?

    Jibu

    A feature that restricts interpretation or generalization. Small samples, short duration, and imperfect measurements are examples.

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    Why are ethics part of experimental design?

    Jibu

    Research must protect participants, organisms, and communities while balancing risks and benefits. Consent and humane treatment are key examples.

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    How does an observational study differ from an experiment?

    Jibu

    It measures variables without assigning the exposure. It can find associations but usually supports weaker causal conclusions.

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    Plants receive 0, 2, or 4 hours of added light, and growth is measured. What is the independent variable?

    Jibu

    Hours of added light. Plant growth is the dependent variable.

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    A fertilizer study gives every plant the same water, soil, and temperature. What are these conditions?

    Jibu

    Controlled variables. Keeping them constant isolates the fertilizer's effect.

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    A drug group improves more than a control group, but the groups were not randomly assigned. What is the main caution?

    Jibu

    Preexisting group differences could explain some improvement. The result is suggestive, but the design weakens a causal claim.

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kadi 446

ATI TEAS 7 Science Flashcards: A&P, Biology, Chemistry & Scientific Reasoning

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