60 Science Practice Questions & Answers

Every Science practice question from the TEAS Practice Test, with the correct answer and a short explanation.

1. Blood leaving the right ventricle enters which structure next?
- A.The left atrium
- B.The aorta
- C.The pulmonary trunk✓ Answer
- D.The inferior vena cava
The right ventricle pumps deoxygenated blood through the pulmonary semilunar valve into the pulmonary trunk, which divides into the pulmonary arteries carrying blood to the lungs for gas exchange. The aorta receives blood only from the left ventricle, and the vena cavae return blood to the right atrium.
Source: ATI TEAS Version 7 Content Outline, objective S.1.3 (cardiovascular system); cardiac blood-flow sequence per StatPearls, Anatomy: Thorax, HeartReport a problem with this question
2. Which valve prevents blood from flowing back from the left ventricle into the left atrium during ventricular contraction?
- A.Bicuspid (mitral) valve✓ Answer
- B.Aortic semilunar valve
- C.Pulmonary semilunar valve
- D.Tricuspid valve
The left atrioventricular valve has two cusps, which is why it is called the bicuspid or mitral valve; rising pressure in the contracting left ventricle snaps it shut so blood is forced into the aorta instead of back into the atrium. The tricuspid valve performs the same job on the right side of the heart.
Source: ATI TEAS Version 7 Content Outline, objective S.1.3 (cardiovascular system); cardiac valve anatomy per StatPearls, Anatomy: Heart ValvesReport a problem with this question
3. Which of these vessels carries deoxygenated blood?
- A.Pulmonary artery✓ Answer
- B.Pulmonary vein
- C.Coronary artery
- D.Aorta
An artery is defined by carrying blood away from the heart, not by its oxygen content. The pulmonary arteries carry deoxygenated blood from the right ventricle to the lungs, while the pulmonary veins are the exception that return oxygenated blood to the left atrium.
Source: ATI TEAS Version 7 Content Outline, objective S.1.3 (cardiovascular system); pulmonary circulation per StatPearls, Physiology: Pulmonary CirculationReport a problem with this question
4. Which structure normally initiates each heartbeat and sets the heart's rhythm?
- A.Sinoatrial (SA) node✓ Answer
- B.Bundle of His
- C.Purkinje fibers
- D.Atrioventricular (AV) node
The SA node in the wall of the right atrium depolarizes spontaneously faster than any other cardiac tissue, so it acts as the pacemaker; the impulse then travels to the AV node, which delays it, and on through the bundle of His, bundle branches, and Purkinje fibers to the ventricles.
Source: ATI TEAS Version 7 Content Outline, objective S.1.3 (cardiovascular system); cardiac conduction per StatPearls, Physiology: Cardiac Conduction SystemReport a problem with this question
5. Which chamber of the heart has the thickest myocardium?
- A.Left atrium
- B.Left ventricle✓ Answer
- C.Right ventricle
- D.Right atrium
The left ventricle must generate enough pressure to eject blood into the aorta and drive it through the entire systemic circuit, which has far greater resistance than the short, low-pressure pulmonary circuit served by the right ventricle; the atria are thin-walled because they only push blood into the ventricles below them.
Source: ATI TEAS Version 7 Content Outline, objective S.1.3 (cardiovascular system); ventricular wall thickness per StatPearls, Anatomy: Thorax, HeartReport a problem with this question
6. If a patient's parathyroid glands are surgically removed, what is the expected effect on blood calcium?
- A.It rises, because the adrenal cortex takes over calcium regulation
- B.It stays the same, because the thyroid gland also secretes parathyroid hormone
- C.It rises, because calcitonin is no longer released
- D.It falls, because parathyroid hormone is no longer available to raise it✓ Answer
Parathyroid hormone is the body's main calcium-raising hormone: it stimulates osteoclast resorption of bone, increases renal calcium reabsorption, and activates vitamin D for intestinal absorption. Without it, the calcium-lowering action of thyroid calcitonin is unopposed and blood calcium falls.
Source: ATI TEAS Version 7 Content Outline, objective S.1.9 (endocrine system); calcium homeostasis per StatPearls, Physiology: Parathyroid HormoneReport a problem with this question
7. Blood glucose falls between meals. Which hormone is released, and what does it do?
- A.Glucagon, which stimulates the liver to break down glycogen and release glucose✓ Answer
- B.Aldosterone, which increases glucose reabsorption in the kidney
- C.Calcitonin, which releases glucose stored in bone
- D.Insulin, which moves glucose from the blood into body cells
Alpha cells of the pancreatic islets secrete glucagon when blood glucose drops; it drives glycogenolysis and gluconeogenesis in the liver, releasing glucose into the blood. Insulin, from the beta cells, does the reverse by promoting glucose uptake into cells when blood glucose is high.
Source: ATI TEAS Version 7 Content Outline, objective S.1.9 (endocrine system); islet hormone action per StatPearls, Physiology: GlucagonReport a problem with this question
8. Antidiuretic hormone (ADH) and oxytocin are released from the posterior pituitary, but where are they actually produced?
- A.The adrenal cortex
- B.The hypothalamus✓ Answer
- C.The pineal gland
- D.The anterior pituitary
Hypothalamic neurons synthesize ADH and oxytocin and transport them down their axons into the posterior pituitary, which is neural tissue that only stores and releases them. The anterior pituitary is the part that manufactures its own hormones, such as GH, TSH, ACTH, FSH, LH, and prolactin.
Source: ATI TEAS Version 7 Content Outline, objective S.1.9 (endocrine system); hypothalamic-neurohypophyseal system per StatPearls, Physiology: Posterior PituitaryReport a problem with this question
9. What fundamentally distinguishes an endocrine gland from an exocrine gland?
- A.Endocrine glands act only on the cells immediately next to them
- B.Endocrine glands secrete digestive enzymes rather than hormones
- C.Endocrine glands release their products through ducts onto a body surface
- D.Endocrine glands are ductless and secrete hormones directly into the bloodstream✓ Answer
Endocrine glands are ductless: their hormones enter the blood and circulate throughout the body, yet they change the activity only of target cells bearing matching receptors. Exocrine glands such as sweat, salivary, and mammary glands deliver their secretions through ducts to a specific surface or cavity.
Source: ATI TEAS Version 7 Content Outline, objective S.1.9 (endocrine system); gland classification per StatPearls, Physiology: Endocrine GlandsReport a problem with this question
10. A neuron carries an impulse from a temperature receptor in the skin to the spinal cord. This neuron is best described as which type?
- A.Somatic motor
- B.Efferent (motor)
- C.Sympathetic postganglionic
- D.Afferent (sensory)✓ Answer
Afferent neurons arrive at the central nervous system, carrying sensory information inward from receptors; efferent neurons exit the CNS to deliver commands to effectors such as muscles and glands. Because the impulse is travelling toward the spinal cord, it is afferent.
Source: ATI TEAS Version 7 Content Outline, objective S.1.5 (nervous system); afferent vs efferent pathways per StatPearls, Neuroanatomy: Sensory NervesReport a problem with this question
11. Which combination of responses results from activation of the sympathetic division of the autonomic nervous system?
- A.Decreased heart rate, dilated pupils, and increased salivation
- B.Decreased heart rate, constricted pupils, and increased digestive activity
- C.Increased heart rate, constricted pupils, and increased intestinal peristalsis
- D.Increased heart rate, dilated pupils, and decreased digestive activity✓ Answer
The sympathetic division produces the fight-or-flight state, using norepinephrine to speed the heart, dilate the pupils and bronchioles, and divert blood away from the digestive tract toward skeletal muscle. The parasympathetic division, acting largely through the vagus nerve and acetylcholine, produces the opposite rest-and-digest pattern.
Source: ATI TEAS Version 7 Content Outline, objective S.1.5 (nervous system); autonomic effects per StatPearls, Physiology: Autonomic Nervous SystemReport a problem with this question
12. In a typical withdrawal reflex, which component receives the signal directly from the sensory neuron?
- A.A sensory receptor in the skin
- B.The motor (efferent) neuron in the brainstem
- C.The effector muscle
- D.An interneuron in the spinal cord✓ Answer
The reflex arc runs receptor to sensory (afferent) neuron to an integration center (an interneuron in the spinal cord) to motor (efferent) neuron to effector. Because integration happens in the cord rather than the brain, the response occurs before the person consciously perceives the stimulus.
Source: ATI TEAS Version 7 Content Outline, objective S.1.5 (nervous system); reflex arc per StatPearls, Neuroanatomy: Spinal ReflexesReport a problem with this question
13. What is the function of the myelin sheath surrounding an axon?
- A.It manufactures the neurotransmitters released at the synapse
- B.It carries sensory information toward the cell body
- C.It supplies the neuron with oxygen from nearby capillaries
- D.It insulates the axon so the impulse jumps between nodes of Ranvier✓ Answer
Myelin is formed by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system, and it electrically insulates the axon. Depolarization can occur only at the unmyelinated nodes of Ranvier, so the impulse leaps from node to node (saltatory conduction), which is far faster than conduction along an unmyelinated fiber.
Source: ATI TEAS Version 7 Content Outline, objective S.1.5 (nervous system); saltatory conduction per StatPearls, Physiology: MyelinReport a problem with this question
14. Which of the following is part of the large intestine?
- A.Jejunum
- B.Ileum
- C.Sigmoid colon✓ Answer
- D.Duodenum
The large intestine consists of the cecum, the ascending, transverse, descending and sigmoid colon, the rectum, and the anal canal, and its main job is reabsorbing water and electrolytes. The duodenum, jejunum, and ileum are the three segments of the small intestine, where most chemical digestion and absorption occur.
Source: ATI TEAS Version 7 Content Outline, objective S.1.4 (digestive system); gastrointestinal anatomy per StatPearls, Anatomy: Abdomen and Pelvis, Large IntestineReport a problem with this question
15. What is the primary role of bile in the digestion of fats?
- A.It carries absorbed fat directly into the bloodstream
- B.It chemically breaks triglycerides into fatty acids and glycerol
- C.It neutralizes the stomach acid entering the small intestine
- D.It emulsifies fat into small droplets, increasing the surface area available to lipase✓ Answer
Bile is produced by the liver and stored and concentrated in the gallbladder, but it is not an enzyme: it acts mechanically, breaking large fat globules into small droplets so pancreatic lipase can reach far more surface. Neutralizing acidic chyme is the job of pancreatic bicarbonate.
Source: ATI TEAS Version 7 Content Outline, objective S.1.4 (digestive system); bile function per StatPearls, Physiology: Bile SecretionReport a problem with this question
16. Most nutrient absorption occurs in which organ, and why?
- A.The small intestine, because villi and microvilli enormously increase its absorptive surface area✓ Answer
- B.The large intestine, because it has the greatest diameter and holds material longest
- C.The stomach, because food remains there the longest
- D.The esophagus, because peristalsis presses nutrients through its wall
Circular folds, villi, and microvilli multiply the lining of the small intestine into an absorptive surface hundreds of times larger than a smooth tube, and this is also where most chemical digestion is completed. The large intestine reabsorbs mainly water and electrolytes, and the stomach absorbs very little.
Source: ATI TEAS Version 7 Content Outline, objective S.1.4 (digestive system); intestinal absorption per StatPearls, Physiology: Small BowelReport a problem with this question
17. By what process does oxygen move from the alveoli into the blood of the pulmonary capillaries?
- A.Active transport that requires ATP
- B.Filtration driven by capillary blood pressure
- C.Osmosis across the alveolar wall
- D.Simple diffusion down a partial pressure gradient✓ Answer
The partial pressure of oxygen is higher in alveolar air than in the venous blood arriving at the lungs, so oxygen diffuses passively across the extremely thin respiratory membrane while carbon dioxide diffuses the other way. No cellular energy is required; osmosis refers specifically to water movement.
Source: ATI TEAS Version 7 Content Outline, objective S.1.2 (respiratory system); alveolar gas exchange per StatPearls, Physiology: Pulmonary Gas ExchangeReport a problem with this question
18. What happens during quiet inhalation?
- A.The lungs actively expand and pull the diaphragm downward
- B.The diaphragm relaxes and the thoracic cavity becomes smaller
- C.The diaphragm contracts and raises the pressure inside the lungs above atmospheric pressure
- D.The diaphragm contracts and flattens, increasing thoracic volume and lowering intrapulmonary pressure✓ Answer
Inhalation is an active, muscular process: the diaphragm contracts downward and the external intercostals lift the ribs, so thoracic volume rises and, by Boyle's law, intrapulmonary pressure falls below atmospheric pressure and air flows in. Quiet exhalation is passive, relying on elastic recoil of the lungs and chest wall.
Source: ATI TEAS Version 7 Content Outline, objective S.1.2 (respiratory system); ventilation mechanics per StatPearls, Physiology: Pulmonary VentilationReport a problem with this question
19. Which structure sets the basic rhythm of breathing, and what stimulus primarily drives it?
- A.The medulla oblongata, responding mainly to rising carbon dioxide and hydrogen ion levels✓ Answer
- B.The cerebellum, responding mainly to falling oxygen levels
- C.The hypothalamus, responding mainly to blood pH set by the kidneys
- D.The thalamus, responding mainly to stretch of the alveoli
Respiratory centers in the medulla oblongata, assisted by the pons, generate the automatic breathing rhythm. Central chemoreceptors sense the rise in hydrogen ions produced when carbon dioxide accumulates, making CO2 the main drive to breathe; low oxygen acts only as a secondary backup stimulus through peripheral chemoreceptors.
Source: ATI TEAS Version 7 Content Outline, objective S.1.2 (respiratory system); respiratory control per StatPearls, Physiology: Respiratory Rate ControlReport a problem with this question
20. Which sequence correctly describes how the nephron forms urine?
- A.Filtration in the glomerulus, then tubular reabsorption, then tubular secretion✓ Answer
- B.Secretion in the glomerulus, then filtration, then reabsorption
- C.Filtration in the collecting duct, then reabsorption in the glomerulus, then secretion
- D.Tubular reabsorption, then glomerular filtration, then secretion
Blood pressure forces water and small solutes out of the glomerulus into the glomerular (Bowman's) capsule while blood cells and large proteins stay behind; useful substances such as glucose, amino acids, sodium, and most water are then reabsorbed, chiefly in the proximal convoluted tubule; finally hydrogen ions, potassium, and drugs are secreted from blood into the tubule, and what remains is urine.
Source: ATI TEAS Version 7 Content Outline, objective S.1.10 (urinary system); nephron function per StatPearls, Physiology: RenalReport a problem with this question
21. Antidiuretic hormone (ADH) is released when a person becomes dehydrated. What is its effect on the kidney?
- A.It stimulates red blood cell production in the bone marrow
- B.It raises the glomerular filtration rate so that more urine is produced
- C.It increases sodium reabsorption and potassium excretion in the distal tubule
- D.It increases water reabsorption in the collecting ducts, producing a small volume of concentrated urine✓ Answer
ADH from the posterior pituitary makes the collecting duct permeable to water by inserting water channels, so water returns to the blood and body fluid is conserved. Sodium and potassium handling is the job of aldosterone, and red blood cell production is stimulated by erythropoietin, which the kidney itself secretes.
Source: ATI TEAS Version 7 Content Outline, objective S.1.10 (urinary system); ADH action per StatPearls, Physiology: Antidiuretic HormoneReport a problem with this question
22. What is the relationship between an antigen and an antibody?
- A.An antigen is a protein made by B cells that binds foreign material
- B.An antibody is the foreign marker that the immune system learns to recognize
- C.An antigen is the foreign marker, and an antibody is the protein made by plasma cells that binds it✓ Answer
- D.Both are produced by the pathogen during an infection
Antigens are foreign molecules, typically on a pathogen's surface, that trigger an immune response. Stimulated B lymphocytes differentiate into plasma cells that secrete antibodies (immunoglobulins) shaped to bind that specific antigen, neutralizing the invader or tagging it for phagocytes.
Source: ATI TEAS Version 7 Content Outline, objective S.1.11 (immune and lymphatic systems); humoral immunity per StatPearls, Physiology: Antibody (Immunoglobulin)Report a problem with this question
23. A newborn is protected from certain infections by antibodies received across the placenta. This is an example of which type of immunity?
- A.Innate immunity provided by physical barriers
- B.Artificially acquired active immunity
- C.Naturally acquired passive immunity✓ Answer
- D.Naturally acquired active immunity
Passive immunity means the individual receives ready-made antibodies produced by another body, whether across the placenta, through breast milk, or by immunoglobulin injection; protection is immediate but temporary because no memory cells are formed. Active immunity, from infection or vaccination, has the person's own lymphocytes make antibodies and lasting memory cells.
Source: ATI TEAS Version 7 Content Outline, objective S.1.11 (immune and lymphatic systems); active vs passive immunity per StatPearls, Immunology: Passive ImmunityReport a problem with this question
24. Which structure attaches one bone to another bone at a joint?
- A.A ligament✓ Answer
- B.The insertion of a muscle
- C.A tendon
- D.Articular cartilage
Ligaments are bands of dense connective tissue running bone to bone; they reinforce the joint capsule and limit excessive movement. Tendons connect muscle to bone so that muscle contraction can pull on the skeleton, and articular cartilage covers the bone ends to reduce friction.
Source: ATI TEAS Version 7 Content Outline, objective S.1.12 (skeletal system); joint connective tissues per StatPearls, Anatomy: LigamentsReport a problem with this question
25. Which description correctly matches cardiac muscle tissue?
- A.Non-striated, voluntary, and found in the wall of the digestive tract
- B.Striated, voluntary, and attached to the skeleton
- C.Non-striated, involuntary, and found in the walls of blood vessels
- D.Striated, involuntary, and joined by intercalated discs✓ Answer
Cardiac muscle is found only in the heart wall; it is striated like skeletal muscle but involuntary and autorhythmic. Its intercalated discs contain gap junctions that let electrical impulses spread cell to cell so the myocardium contracts as a coordinated unit, unlike non-striated smooth muscle in hollow organs or voluntary skeletal muscle on bones.
Source: ATI TEAS Version 7 Content Outline, objective S.1.6 (muscular system); muscle tissue types per StatPearls, Histology: Cardiac MuscleReport a problem with this question
26. According to the sliding filament theory, how does a muscle fiber shorten?
- A.Myosin heads form cross-bridges and pull the actin filaments toward the center of the sarcomere✓ Answer
- B.Calcium binds directly to myosin and folds the thick filament
- C.The actin and myosin filaments themselves become shorter
- D.The Z lines dissolve and re-form farther apart
Calcium released inside the fiber binds troponin, which shifts tropomyosin off the binding sites on actin; myosin heads then attach, pivot using ATP, and slide the thin filaments inward so the Z lines of each sarcomere move closer together. The filaments slide past one another and do not change length.
Source: ATI TEAS Version 7 Content Outline, objective S.1.6 (muscular system); sliding filament mechanism per StatPearls, Physiology: Muscle ContractionReport a problem with this question
27. In anatomical position, how is the wrist described in relation to the elbow?
- A.Superior
- B.Distal✓ Answer
- C.Medial
- D.Proximal
Proximal and distal are used only for the limbs and describe distance from the point where the limb attaches to the trunk. The wrist lies farther from the shoulder attachment than the elbow does, so it is distal to the elbow; medial and lateral instead describe position relative to the body's midline.
Source: ATI TEAS Version 7 Content Outline, objective S.1.1 (general anatomical orientation); directional terminology per StatPearls, Anatomy: Anatomical Position and Directional TermsReport a problem with this question
28. Which of the following is an example of positive feedback?
- A.Insulin release that lowers an elevated blood glucose level
- B.Oxytocin release during labor, which strengthens contractions and triggers still more oxytocin✓ Answer
- C.Shivering that generates heat when body temperature falls
- D.Sweating that cools the body when core temperature rises
Positive feedback amplifies the original change instead of reversing it, and it continues until a definite endpoint such as delivery of the baby or formation of a clot. The other three examples are negative feedback, the usual homeostatic pattern in which the response counteracts the change and returns the variable toward its set point.
Source: ATI TEAS Version 7 Content Outline, objective S.1.1 (homeostasis and feedback); feedback mechanisms per StatPearls, Physiology: HomeostasisReport a problem with this question
29. Which layer of the skin is avascular and forms the body's outermost protective barrier?
- A.Epidermis✓ Answer
- B.Hypodermis (subcutaneous layer)
- C.Dermis
- D.Papillary layer of the dermis
The epidermis is stratified squamous epithelium with no blood vessels of its own, so it is nourished by diffusion from the dermis below; its outermost stratum corneum of dead, keratin-filled cells resists abrasion, blocks pathogens, and limits water loss. The dermis is the vascular layer holding vessels, nerves, glands, and hair follicles.
Source: ATI TEAS Version 7 Content Outline, objective S.1.8 (integumentary system); skin layers per StatPearls, Anatomy: Skin (Integument), EpidermisReport a problem with this question
30. In the female reproductive tract, where does fertilization normally occur?
- A.In the uterus, on the endometrium
- B.In the cervix
- C.In the fallopian (uterine) tube✓ Answer
- D.In the ovary
After ovulation the oocyte is swept into the uterine tube, and sperm travelling upward usually meet it there, most often in the ampulla. The resulting zygote is then moved along the tube to the uterus, where implantation into the endometrium takes place several days later.
Source: ATI TEAS Version 7 Content Outline, objective S.1.7 (reproductive systems); site of fertilization per StatPearls, Anatomy: Abdomen and Pelvis, Fallopian TubeReport a problem with this question
31. Which organelle modifies, packages, and ships proteins to their final destinations?
- A.Ribosome
- B.Lysosome
- C.Smooth endoplasmic reticulum
- D.Golgi apparatus✓ Answer
The Golgi apparatus receives proteins from the rough ER, chemically modifies them, and sorts them into vesicles for secretion or delivery. Ribosomes build proteins, lysosomes digest material with hydrolytic enzymes, and smooth ER synthesizes lipids.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (cell structure, function, and organization)Report a problem with this question
32. Which of the following structures is present in eukaryotic cells but absent in prokaryotic cells?
- A.Membrane-bound nucleus✓ Answer
- B.Cytoplasm
- C.Plasma membrane
- D.Ribosomes
The defining difference is compartmentalization: eukaryotes enclose their DNA in a true nucleus bounded by a nuclear membrane and have other membrane-bound organelles, while prokaryotes such as bacteria keep their DNA in a nucleoid region. Ribosomes, a plasma membrane, and cytoplasm occur in both cell types.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (prokaryotic vs. eukaryotic cell organization)Report a problem with this question
33. A red blood cell is placed in a hypertonic solution. Which of the following will happen to the cell?
- A.It will stay exactly the same size
- B.It will use ATP to pump water inward
- C.It will swell and may burst
- D.It will shrink as water moves out of the cell✓ Answer
A hypertonic solution has a higher solute concentration outside the cell than inside, so osmosis moves water down its concentration gradient out of the cell and it shrinks (crenates). A hypotonic solution would cause swelling and lysis; an isotonic solution produces no net water movement.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (plasma membrane transport and tonicity)Report a problem with this question
34. Which process moves a substance across the plasma membrane from an area of lower concentration to an area of higher concentration?
- A.Active transport✓ Answer
- B.Simple diffusion
- C.Facilitated diffusion
- D.Osmosis
Only active transport moves a substance against its concentration gradient, and because this is energetically unfavorable it requires ATP and a protein pump such as the sodium-potassium pump. Osmosis, simple diffusion, and facilitated diffusion are all passive and move substances down the gradient without energy input.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (passive vs. active membrane transport)Report a problem with this question
35. Which of the following is the monomer, or building block, of proteins?
- A.Fatty acid
- B.Monosaccharide
- C.Nucleotide
- D.Amino acid✓ Answer
Proteins are polymers of amino acids joined by peptide bonds, and the sequence of amino acids determines the protein's folded shape and function. Nucleotides are the monomers of nucleic acids, monosaccharides of carbohydrates, and fatty acids plus glycerol build lipids.
Source: ATI TEAS 7 Content Outline, objective S.2.4 (structure and function of basic macromolecules)Report a problem with this question
36. How does an enzyme increase the rate of a chemical reaction in a cell?
- A.By changing which products the reaction forms
- B.By being permanently consumed as a reactant
- C.By raising the temperature of the cell
- D.By lowering the activation energy the reaction requires✓ Answer
An enzyme is a biological catalyst: its active site binds the substrate in a way that lowers the activation energy barrier, so the reaction proceeds faster at body temperature. The enzyme is not used up and does not change the products, though extreme heat or pH will denature it and destroy the active site's shape.
Source: ATI TEAS 7 Content Outline, objective S.2.4 (enzymes as protein catalysts)Report a problem with this question
37. In a eukaryotic cell, where does glycolysis take place?
- A.In the nucleus
- B.On the inner mitochondrial membrane
- C.In the mitochondrial matrix
- D.In the cytoplasm✓ Answer
Glycolysis splits one glucose molecule into two pyruvate molecules in the cytoplasm, requires no oxygen, and yields a net 2 ATP. The Krebs (citric acid) cycle then runs in the mitochondrial matrix, and the electron transport chain, which produces most of the ATP, is embedded in the inner mitochondrial membrane.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (cellular respiration: stages and locations)Report a problem with this question
38. Which pair lists the raw materials a plant uses during photosynthesis?
- A.Glucose and oxygen
- B.Carbon dioxide and water✓ Answer
- C.Glucose and carbon dioxide
- D.Oxygen and nitrogen
In the chloroplast, light energy drives the reaction 6 CO2 + 6 H2O to C6H12O6 + 6 O2, so carbon dioxide and water are the reactants while glucose and oxygen are the products. Cellular respiration is essentially the reverse, consuming glucose and oxygen.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (photosynthesis overview)Report a problem with this question
39. Which of the following describes the cells produced by meiosis?
- A.Two genetically identical diploid cells
- B.Two genetically unique haploid cells
- C.Four genetically unique haploid cells✓ Answer
- D.Four genetically identical diploid cells
Meiosis follows one round of DNA replication with two divisions, so the chromosome number is halved and four haploid gametes result. Crossing over in prophase I and independent assortment make each gamete genetically unique, whereas mitosis produces two identical diploid body cells for growth and repair.
Source: ATI TEAS 7 Content Outline, objective S.2.1 (cell cycle: mitosis vs. meiosis outcomes)Report a problem with this question
40. During transcription, which RNA base pairs with adenine on the DNA template strand?
- A.Guanine
- B.Cytosine
- C.Thymine
- D.Uracil✓ Answer
RNA substitutes uracil for thymine, so adenine on the DNA template pairs with uracil in the new RNA strand while guanine still pairs with cytosine. This is a structural difference between the two nucleic acids, along with RNA being single stranded and containing ribose instead of deoxyribose.
Source: ATI TEAS 7 Content Outline, objective S.2.2 (genetic material and protein structure; DNA/RNA base pairing)Report a problem with this question
41. Two parents are each heterozygous (Aa) for a trait in which A is dominant. What percentage of their offspring is expected to show the recessive phenotype?
- A.75%
- B.0%
- C.25%✓ Answer
- D.50%
A Punnett square for Aa x Aa gives the genotype ratio 1 AA : 2 Aa : 1 aa, and only the homozygous recessive aa individuals express the recessive phenotype. That is one of four boxes, or 25%, which is why the classic phenotype ratio is 3 dominant to 1 recessive.
Source: ATI TEAS 7 Content Outline, objective S.2.3 (Mendel's law of segregation; monohybrid Punnett square)Report a problem with this question
42. The atomic number of an element is determined by which of the following?
- A.The total number of protons and neutrons
- B.The number of protons in the nucleus✓ Answer
- C.The number of electrons in the outer shell
- D.The number of neutrons in the nucleus
The atomic number equals the number of protons, and the proton count is what defines the element's identity: change it and you have a different element. The mass number is protons plus neutrons, and electron count equals proton count only in a neutral atom.
Source: ATI TEAS 7 Content Outline, objective S.3.1 (basic atomic structure)Report a problem with this question
43. Two atoms of the same element that have different mass numbers differ in the number of which particle?
- A.Valence electrons
- B.Electrons
- C.Neutrons✓ Answer
- D.Protons
Such atoms are isotopes: they have the same number of protons, which keeps them the same element, but different numbers of neutrons, which changes the mass number (protons plus neutrons). Because bonding depends on electrons, isotopes of an element behave almost identically in chemical reactions.
Source: ATI TEAS 7 Content Outline, objective S.3.1 (isotopes and mass number)Report a problem with this question
44. Which of the following best describes an ionic bond?
- A.Electrons move freely among closely packed metal atoms
- B.A hydrogen atom is weakly attracted to a nearby polar molecule
- C.Electrons are transferred from a metal to a nonmetal✓ Answer
- D.Electrons are shared between two nonmetals
In an ionic bond, valence electrons are transferred from a metal to a nonmetal, creating a positive cation and a negative anion that are held together by electrostatic attraction, as in NaCl. Shared electrons describe a covalent bond, the third option describes hydrogen bonding, and the fourth describes metallic bonding.
Source: ATI TEAS 7 Content Outline, objective S.3.1 (chemical bonding: ionic, covalent, hydrogen)Report a problem with this question
45. Elements in the same group (vertical column) of the periodic table behave similarly because they have the same number of which of the following?
- A.Valence electrons✓ Answer
- B.Protons
- C.Neutrons
- D.Energy levels, or electron shells
Chemical behavior is governed by the outermost, or valence, electrons, and every element in a group has the same number of them, so they form the same kinds of bonds. This is why the halogens are all highly reactive and the noble gases, with full valence shells, are essentially inert; the number of occupied shells changes down a group and corresponds to the period number.
Source: ATI TEAS 7 Content Outline, objective S.3.1 (organization of the periodic table and periodic trends)Report a problem with this question
46. Which of the following explains why ice floats on liquid water?
- A.Ice is nonpolar while liquid water is polar
- B.Water molecules lose mass when they freeze
- C.Ice traps dissolved air that makes it lighter
- D.Hydrogen bonds hold the molecules in an open lattice, so ice is less dense than liquid water✓ Answer
Water is polar, so hydrogen bonds form between molecules; when water freezes those bonds lock the molecules into a rigid open crystal that spaces them farther apart than in the liquid, lowering the density. Most substances are denser as solids, which makes this one of water's unusual properties, along with its high specific heat and strong cohesion.
Source: ATI TEAS 7 Content Outline, objective S.3.2 (properties of water; hydrogen bonding and density)Report a problem with this question
47. Which of the following is a chemical change rather than a physical change?
- A.Ice melting into liquid water
- B.Iron rusting on a nail✓ Answer
- C.Dry ice subliming into a gas
- D.Sugar dissolving in water
A chemical change produces a new substance with new chemical properties: rusting combines iron with oxygen to form iron oxide, which cannot simply be reversed. Melting, dissolving, and sublimation change only the physical form or state; the substance's composition stays the same.
Source: ATI TEAS 7 Content Outline, objective S.3.2 (physical properties and changes of matter vs. chemical change)Report a problem with this question
48. When balancing a chemical equation, which of the following may be changed?
- A.The coefficients placed in front of the formulas✓ Answer
- B.The total mass of the reactants
- C.The subscripts inside a chemical formula
- D.The identity of the products
The law of conservation of mass requires the same number of atoms of each element on both sides, and only coefficients, which count whole molecules, may be adjusted to achieve that. Changing a subscript would change the formula into a different substance, for example turning H2O into H2O2.
Source: ATI TEAS 7 Content Outline, objective S.3.3 (chemical reactions; law of conservation of mass)Report a problem with this question
49. A solution with a pH of 3 is how many times more acidic than a solution with a pH of 5?
- A.10 times
- B.20 times
- C.100 times✓ Answer
- D.2 times
The pH scale is logarithmic in base 10, so each whole-number step represents a tenfold change in hydrogen ion concentration. Two units therefore equal 10 x 10, or 100 times more acidic, not twice as acidic.
Source: ATI TEAS 7 Content Outline, objective S.3.6 (acids and bases; logarithmic pH scale)Report a problem with this question
50. Raising the temperature of water generally has which effect on the solubility of a solid solute such as table salt or sugar?
- A.Solubility decreases
- B.Solubility is unaffected
- C.The solute becomes the solvent
- D.Solubility increases✓ Answer
Higher temperature gives solvent molecules more kinetic energy, so they collide with and pull apart the solute more effectively and more solid dissolves before the solution becomes saturated. Gases behave the opposite way: their solubility in a liquid falls as temperature rises.
Source: ATI TEAS 7 Content Outline, objective S.3.5 (properties of solutions; factors affecting solubility)Report a problem with this question
51. A researcher tests whether the amount of fertilizer affects plant height. Which of the following is the independent variable?
- A.The amount of fertilizer applied✓ Answer
- B.The type of soil used
- C.The height of the plants
- D.The amount of water each plant receives
The independent variable is the factor the researcher deliberately manipulates, here the fertilizer amount, and it is plotted on the x-axis. Plant height is the measured outcome, or dependent variable, while water and soil type are controlled variables held constant so they cannot explain the results.
Source: ATI TEAS 7 Content Outline, objective S.4.4 (applying the scientific method; identifying variables)Report a problem with this question
52. On a properly constructed graph of experimental data, the dependent variable is placed on which axis?
- A.The x-axis, because it is the variable being manipulated
- B.The y-axis, because it is the response being measured✓ Answer
- C.Either axis, as long as both are labeled
- D.Neither axis; it appears only in the data table
By convention the manipulated independent variable goes on the horizontal x-axis and the measured dependent variable goes on the vertical y-axis, so the graph reads as the effect of x on y. Following this convention lets any reader identify cause and response and judge whether the relationship is direct or inverse.
Source: ATI TEAS 7 Content Outline, objective S.4.3 (predicting and representing relationships; graphing conventions)Report a problem with this question
53. What is the purpose of the control group in an experiment?
- A.To remove the need to measure a dependent variable
- B.To provide an untreated baseline for comparison✓ Answer
- C.To guarantee that the hypothesis is supported
- D.To increase the number of trials performed
The control group is treated identically except that it does not receive the experimental treatment, often getting a placebo instead, so it shows what happens with no intervention. Comparing the treated group to that baseline is what allows any difference to be attributed to the independent variable.
Source: ATI TEAS 7 Content Outline, objective S.4.4 (experimental design; control group)Report a problem with this question
54. A student repeats the same measurement five times and obtains nearly identical results each time. This best demonstrates that the measurement is which of the following?
- A.Reliable✓ Answer
- B.Biased
- C.Free of all sources of error
- D.Valid
Reliability means consistency: repeated trials under the same conditions produce the same result, which is exactly what repeating a measurement demonstrates. Validity is a separate question of whether the tool actually measures what it is supposed to, so a scale that is miscalibrated by the same amount every time is reliable but not valid.
Source: ATI TEAS 7 Content Outline, objective S.4.4 (reliability vs. validity in a scientific investigation)Report a problem with this question
55. Which of the following best describes a scientific hypothesis?
- A.A proven fact that all scientists accept
- B.A broad explanation already supported by a large body of evidence
- C.A statement describing what happens under set conditions without explaining why
- D.A testable, falsifiable explanation that data can support or refute✓ Answer
A hypothesis is a proposed explanation stated so that an experiment could show it to be wrong, which is what makes it scientifically useful; it is often phrased as an if-then prediction. The third option defines a scientific theory and the fourth defines a scientific law.
Source: ATI TEAS 7 Content Outline, objective S.4.2 (logic and evidence; hypothesis vs. theory vs. law)Report a problem with this question
56. Which tool should be used to measure the volume of a liquid most precisely, and how should it be read?
- A.A triple-beam balance, read once the pointer settles
- B.A beaker, read at the highest point of the liquid
- C.A graduated cylinder, read at the bottom of the meniscus✓ Answer
- D.A thermometer, read after one minute
A graduated cylinder has narrow, closely spaced gradations calibrated for accurate volume, and because water curves upward at the glass the reading is taken at eye level from the bottom of the meniscus. Beakers give only rough volume estimates, and balances and thermometers measure mass and temperature, not volume.
Source: ATI TEAS 7 Content Outline, objective S.4.1 (basic scientific measurements and measurement tools)Report a problem with this question
57. A sample has a volume of 2,500 mL. What is this volume expressed in liters?
- A.2.5 L✓ Answer
- B.25 L
- C.250 L
- D.0.25 L
The metric prefix milli- means one thousandth, so 1 L equals 1,000 mL and converting from milliliters to liters means dividing by 1,000. Dividing 2,500 by 1,000 gives 2.5 L, and moving to a larger unit must always give a smaller number.
Source: ATI TEAS 7 Content Outline, objective S.4.1 (SI units and metric prefixes)Report a problem with this question
58. A survey finds that people who drink more coffee also report more sleep problems. Which conclusion is best supported by these data?
- A.Sleep problems cause people to drink more coffee
- B.No relationship exists between the two variables
- C.There is a correlation between the two, but causation has not been established✓ Answer
- D.Coffee causes sleep problems
Observational data can show that two variables vary together, but correlation alone cannot establish causation because the direction of the effect could be reversed or a third confounding variable could drive both. Only a controlled experiment with random assignment and a control group supports a causal claim.
Source: ATI TEAS 7 Content Outline, objective S.4.2 (applying logic and evidence to a scientific explanation)Report a problem with this question
59. In an experiment, as the pressure on a gas was increased from 1 atm to 4 atm, its measured volume fell from 8 mL to 2 mL. These data show which type of relationship?
- A.A relationship that cannot be determined from two variables
- B.An inverse relationship✓ Answer
- C.No relationship
- D.A direct relationship
In an inverse relationship one variable rises while the other falls, which is exactly what the data show: pressure quadrupled while volume dropped to one fourth, keeping the product roughly constant. A direct relationship would have both variables increasing together.
Source: ATI TEAS 7 Content Outline, objective S.4.3 (predicting relationships; interpreting data as direct or inverse)Report a problem with this question
60. A student tests whether a new plant food increases growth, but gives the treated plants more sunlight than the untreated plants. Which flaw does this introduce?
- A.A hypothesis cannot be written for this experiment
- B.A second variable was not held constant, so results cannot be attributed to the plant food✓ Answer
- C.The experiment has too few dependent variables
- D.The sample size is automatically too small
Sound experimental design requires that every factor except the independent variable be held constant across groups. Because sunlight also differed, it is a confounding variable and any growth difference could be due to light rather than the plant food, so no valid conclusion can be drawn.
Source: ATI TEAS 7 Content Outline, objective S.4.4 (experimental design critique; controlled variables and sources of error)Report a problem with this question

Practice questions based on the ATI TEAS test outline. Not affiliated with ATI. The English & Language section is practiced in English. About the TEAS (ATI) →

1. Blood leaving the right ventricle enters which structure next?

2. Which valve prevents blood from flowing back from the left ventricle into the left atrium during ventricular contraction?

3. Which of these vessels carries deoxygenated blood?

4. Which structure normally initiates each heartbeat and sets the heart's rhythm?

5. Which chamber of the heart has the thickest myocardium?

6. If a patient's parathyroid glands are surgically removed, what is the expected effect on blood calcium?

7. Blood glucose falls between meals. Which hormone is released, and what does it do?

8. Antidiuretic hormone (ADH) and oxytocin are released from the posterior pituitary, but where are they actually produced?

9. What fundamentally distinguishes an endocrine gland from an exocrine gland?

10. A neuron carries an impulse from a temperature receptor in the skin to the spinal cord. This neuron is best described as which type?

11. Which combination of responses results from activation of the sympathetic division of the autonomic nervous system?

12. In a typical withdrawal reflex, which component receives the signal directly from the sensory neuron?

13. What is the function of the myelin sheath surrounding an axon?

14. Which of the following is part of the large intestine?

15. What is the primary role of bile in the digestion of fats?

16. Most nutrient absorption occurs in which organ, and why?

17. By what process does oxygen move from the alveoli into the blood of the pulmonary capillaries?

18. What happens during quiet inhalation?

19. Which structure sets the basic rhythm of breathing, and what stimulus primarily drives it?

20. Which sequence correctly describes how the nephron forms urine?

21. Antidiuretic hormone (ADH) is released when a person becomes dehydrated. What is its effect on the kidney?

22. What is the relationship between an antigen and an antibody?

23. A newborn is protected from certain infections by antibodies received across the placenta. This is an example of which type of immunity?

24. Which structure attaches one bone to another bone at a joint?

25. Which description correctly matches cardiac muscle tissue?

26. According to the sliding filament theory, how does a muscle fiber shorten?

27. In anatomical position, how is the wrist described in relation to the elbow?

28. Which of the following is an example of positive feedback?

29. Which layer of the skin is avascular and forms the body's outermost protective barrier?

30. In the female reproductive tract, where does fertilization normally occur?

31. Which organelle modifies, packages, and ships proteins to their final destinations?

32. Which of the following structures is present in eukaryotic cells but absent in prokaryotic cells?

33. A red blood cell is placed in a hypertonic solution. Which of the following will happen to the cell?

34. Which process moves a substance across the plasma membrane from an area of lower concentration to an area of higher concentration?

35. Which of the following is the monomer, or building block, of proteins?

36. How does an enzyme increase the rate of a chemical reaction in a cell?

37. In a eukaryotic cell, where does glycolysis take place?

38. Which pair lists the raw materials a plant uses during photosynthesis?

39. Which of the following describes the cells produced by meiosis?

40. During transcription, which RNA base pairs with adenine on the DNA template strand?

41. Two parents are each heterozygous (Aa) for a trait in which A is dominant. What percentage of their offspring is expected to show the recessive phenotype?

42. The atomic number of an element is determined by which of the following?

43. Two atoms of the same element that have different mass numbers differ in the number of which particle?

44. Which of the following best describes an ionic bond?

45. Elements in the same group (vertical column) of the periodic table behave similarly because they have the same number of which of the following?

46. Which of the following explains why ice floats on liquid water?

47. Which of the following is a chemical change rather than a physical change?

48. When balancing a chemical equation, which of the following may be changed?

49. A solution with a pH of 3 is how many times more acidic than a solution with a pH of 5?

50. Raising the temperature of water generally has which effect on the solubility of a solid solute such as table salt or sugar?

51. A researcher tests whether the amount of fertilizer affects plant height. Which of the following is the independent variable?

52. On a properly constructed graph of experimental data, the dependent variable is placed on which axis?

53. What is the purpose of the control group in an experiment?

54. A student repeats the same measurement five times and obtains nearly identical results each time. This best demonstrates that the measurement is which of the following?

55. Which of the following best describes a scientific hypothesis?

56. Which tool should be used to measure the volume of a liquid most precisely, and how should it be read?

57. A sample has a volume of 2,500 mL. What is this volume expressed in liters?

58. A survey finds that people who drink more coffee also report more sleep problems. Which conclusion is best supported by these data?

59. In an experiment, as the pressure on a gas was increased from 1 atm to 4 atm, its measured volume fell from 8 mL to 2 mL. These data show which type of relationship?

60. A student tests whether a new plant food increases growth, but gives the treated plants more sunlight than the untreated plants. Which flaw does this introduce?