What posture defines the standard anatomical position?

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

In anatomical language, what does superior mean?

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

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

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

Why does the body use feedback mechanisms?

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

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

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

What does anterior mean in human anatomy?

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

Which plane divides the body into upper and lower portions?

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

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

Which major body cavity contains the brain and spinal cord?

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

What does medial mean in anatomical language?

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

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

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

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

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

Which major body cavity contains the thoracic and abdominopelvic cavities?

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

What does proximal mean when describing a limb?

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

How does positive feedback differ from negative feedback?

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

Which tissue type covers surfaces and lines body cavities?

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

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

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

What shared property lets muscle tissue produce movement?

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

Which tissue type rapidly communicates by electrical signals?

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

Why are tightly packed epithelial cells well suited for barriers?

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

What distinguishes connective tissue from epithelial tissue?

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

What are the four basic human tissue types?

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

What makes a structure an organ rather than a tissue?

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

What are the skeletal system's main functions?

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

What belongs to the axial skeleton?

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

How do compact and spongy bone differ?

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

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

Which bone cell builds new bone matrix?

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

What belongs to the appendicular skeleton?

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

What is the main role of red bone marrow?

Blood-cell production. This process is called hematopoiesis.

Which joint class allows the greatest range of motion?

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

Which bone cell breaks down bone matrix?

An osteoclast. Bone resorption helps remodeling and mineral balance.

What does a ligament connect?

Bone to bone. A tendon connects muscle to bone.

What is the shaft of a long bone called?

The diaphysis. The enlarged ends are the epiphyses.

Why is bone important to blood-calcium balance?

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

What is stored mainly in yellow bone marrow?

Fat. It serves as an energy reserve.

What does articular cartilage do at a synovial joint?

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

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

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

What is bone remodeling?

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

Which muscle tissue is usually under voluntary control?

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

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

What does a tendon connect?

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

Which proteins slide past one another during muscle contraction?

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

Where is smooth muscle commonly found?

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

What ion exposes binding sites needed for skeletal muscle contraction?

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

How do antagonistic muscle pairs move a joint?

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

Why does muscle contraction require ATP?

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

Which muscle tissue makes up the heart wall?

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

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

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

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

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

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

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.

Eftir höfund Flashcards Open Source App

Um þennan stokk

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.

Spjöld í þessum stokki

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

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

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