ATI TEAS 7 SCIENCE EXAM PRACTICE | COMPREHENSIVE STUDY GUIDE | ADVANCED
TESTBANK | PRACTICE QUESTIONS & ANSWERS | LATEST UPDATE 2026/2027
TABLE OF CONTENTS
i. Human Anatomy and Physiology
ii. Biology and Cellular Processes
iii. Genetics and Molecular Biology
iv. Microbiology and Immunology
v. Chemistry and Biochemistry
vi. Scientific Reasoning and Experimental Design
vii. Physiological Integration and Homeostasis
INTRODUCTION
This comprehensive ATI TEAS 7 Science practice examination emphasizes anatomy and
physiology, biology, genetics, microbiology, chemistry, and scientific reasoning. The
questions are designed to challenge students beyond simple memorization by
requiring interpretation of physiological processes, molecular mechanisms,
experimental evidence, homeostatic regulation, and biochemical relationships. Students
should expect realistic scenarios, carefully constructed distractors, multi-step reasoning,
and application of foundational scientific principles. The examination is particularly
useful for learners preparing for competitive nursing and allied-health programs who
need strong conceptual mastery rather than isolated factual recall. The questions
progress through interconnected scientific concepts and emphasize the ability to
identify mechanisms, predict outcomes, evaluate evidence, and distinguish closely
related biological and chemical processes.
Question 1
A patient experiences severe dehydration after prolonged gastrointestinal fluid loss.
Laboratory testing reveals increased plasma osmolarity. Which physiological response
most directly promotes restoration of plasma osmolarity?
A. Decreased secretion of antidiuretic hormone and increased urine production
B. Increased secretion of antidiuretic hormone and increased water reabsorption by the
kidneys
C. Increased secretion of atrial natriuretic peptide and increased sodium excretion
D. Decreased hypothalamic osmoreceptor activity and decreased thirst
,🔴 Correct Answer: B. Increased secretion of antidiuretic hormone and increased
water reabsorption by the kidneys.
🔵 Explanation: Increased plasma osmolarity stimulates hypothalamic osmoreceptors,
promoting thirst and antidiuretic hormone secretion. ADH increases water permeability of
the renal collecting ducts, allowing greater water reabsorption and helping restore
plasma osmolarity.
Question 2
A researcher inhibits the sodium-potassium ATPase in a population of human cells.
Which immediate consequence would most directly impair the cells' ability to maintain
normal resting membrane potential?
A. Increased intracellular sodium concentration
B. Increased intracellular calcium concentration caused by enhanced ATP production
C. Decreased extracellular potassium concentration
D. Increased synthesis of membrane phospholipids
🔴 Correct Answer: A. Increased intracellular sodium concentration.
🔵 Explanation: The sodium-potassium ATPase normally transports three Na⁺ ions out of
the cell and two K⁺ ions into the cell using ATP. Inhibition causes intracellular Na⁺ to
accumulate and disrupts the electrochemical gradients that contribute to resting
membrane potential.
Question 3
A mutation changes a codon in an mRNA molecule from UAU to UAA. Which outcome
is most likely?
A. The mutation causes insertion of an additional amino acid
B. The mutation changes one amino acid into another
C. The mutation creates a premature termination signal
D. The mutation has no possible effect because all codons encode amino acids
🔴 Correct Answer: C. The mutation creates a premature termination signal.
🔵 Explanation: UAU encodes tyrosine, whereas UAA is a stop codon. Conversion of UAU
to UAA therefore creates a nonsense mutation that can terminate translation prematurely
and produce a truncated protein.
Question 4
,A student places identical plant cells into three solutions. Cells placed in solution X
become swollen, cells in solution Y remain approximately unchanged, and cells in
solution Z become plasmolyzed. Which classification is most consistent with these
observations?
A. X is hypertonic, Y is hypotonic, and Z is isotonic
B. X is hypotonic, Y is isotonic, and Z is hypertonic
C. X is isotonic, Y is hypertonic, and Z is hypotonic
D. X is hypertonic, Y is isotonic, and Z is hypotonic
🔴 Correct Answer: B. X is hypotonic, Y is isotonic, and Z is hypertonic.
🔵 Explanation: Water enters cells in a hypotonic environment, producing swelling. An
isotonic environment causes no substantial net water movement. A hypertonic
environment draws water out of cells and can cause plant cells to plasmolyze.
Question 5
A patient has damage to the alveolar-capillary membrane that substantially increases
its thickness. Which change would most directly reduce oxygen transfer from the
alveoli into pulmonary capillary blood?
A. Increased oxygen partial pressure in the alveoli
B. Decreased diffusion distance across the respiratory membrane
C. Increased diffusion distance across the respiratory membrane
D. Increased hemoglobin concentration in erythrocytes
🔴 Correct Answer: C. Increased diffusion distance across the respiratory membrane.
🔵 Explanation: According to principles governing diffusion, increasing membrane
thickness increases diffusion distance and decreases the rate of gas transfer. Although
hemoglobin concentration can influence oxygen-carrying capacity, it does not directly
correct impaired diffusion across a thickened membrane.
Question 6
A researcher measures enzyme activity at progressively increasing temperatures.
Activity rises until 37°C and then rapidly declines as temperature continues increasing.
Which explanation best accounts for the decline?
A. The substrate becomes permanently unavailable at temperatures above 37°C
B. Increased temperature necessarily reduces molecular collisions
, C. Excessive heat disrupts the enzyme's three-dimensional structure
D. The enzyme begins converting all substrates into inhibitors
🔴 Correct Answer: C. Excessive heat disrupts the enzyme's three-dimensional
structure.
🔵 Explanation: Enzymes depend on a specific three-dimensional conformation for
catalytic activity. Temperatures above an enzyme's optimal range can disrupt noncovalent
interactions that maintain its structure, altering the active site and reducing catalytic
activity.
Question 7
A person has type O-negative blood and requires an emergency red blood cell
transfusion when the patient's blood type cannot immediately be determined. Why can
O-negative packed red blood cells generally be used in this situation?
A. They contain both A and B antigens but lack Rh antibodies
B. Their erythrocytes lack A, B, and Rh(D) antigens
C. They contain anti-A and anti-B antigens instead of antibodies
D. They suppress the recipient's adaptive immune response
🔴 Correct Answer: B. Their erythrocytes lack A, B, and Rh(D) antigens.
🔵 Explanation: O-negative erythrocytes lack A, B, and Rh(D) surface antigens, reducing
the likelihood that naturally occurring recipient antibodies will recognize and attack the
transfused red blood cells. This is why O-negative packed cells are commonly considered
the universal donor type for red blood cells.
Question 8
A patient has a deficiency of pancreatic bicarbonate secretion into the duodenum.
Which digestive consequence would most directly result?
A. Increased gastric acid neutralization
B. Reduced activity of pancreatic enzymes that function optimally near neutral or
alkaline pH
C. Increased pepsin activity throughout the small intestine
D. Increased absorption of intact dietary proteins
🔴 Correct Answer: B. Reduced activity of pancreatic enzymes that function
optimally near neutral or alkaline pH.
TESTBANK | PRACTICE QUESTIONS & ANSWERS | LATEST UPDATE 2026/2027
TABLE OF CONTENTS
i. Human Anatomy and Physiology
ii. Biology and Cellular Processes
iii. Genetics and Molecular Biology
iv. Microbiology and Immunology
v. Chemistry and Biochemistry
vi. Scientific Reasoning and Experimental Design
vii. Physiological Integration and Homeostasis
INTRODUCTION
This comprehensive ATI TEAS 7 Science practice examination emphasizes anatomy and
physiology, biology, genetics, microbiology, chemistry, and scientific reasoning. The
questions are designed to challenge students beyond simple memorization by
requiring interpretation of physiological processes, molecular mechanisms,
experimental evidence, homeostatic regulation, and biochemical relationships. Students
should expect realistic scenarios, carefully constructed distractors, multi-step reasoning,
and application of foundational scientific principles. The examination is particularly
useful for learners preparing for competitive nursing and allied-health programs who
need strong conceptual mastery rather than isolated factual recall. The questions
progress through interconnected scientific concepts and emphasize the ability to
identify mechanisms, predict outcomes, evaluate evidence, and distinguish closely
related biological and chemical processes.
Question 1
A patient experiences severe dehydration after prolonged gastrointestinal fluid loss.
Laboratory testing reveals increased plasma osmolarity. Which physiological response
most directly promotes restoration of plasma osmolarity?
A. Decreased secretion of antidiuretic hormone and increased urine production
B. Increased secretion of antidiuretic hormone and increased water reabsorption by the
kidneys
C. Increased secretion of atrial natriuretic peptide and increased sodium excretion
D. Decreased hypothalamic osmoreceptor activity and decreased thirst
,🔴 Correct Answer: B. Increased secretion of antidiuretic hormone and increased
water reabsorption by the kidneys.
🔵 Explanation: Increased plasma osmolarity stimulates hypothalamic osmoreceptors,
promoting thirst and antidiuretic hormone secretion. ADH increases water permeability of
the renal collecting ducts, allowing greater water reabsorption and helping restore
plasma osmolarity.
Question 2
A researcher inhibits the sodium-potassium ATPase in a population of human cells.
Which immediate consequence would most directly impair the cells' ability to maintain
normal resting membrane potential?
A. Increased intracellular sodium concentration
B. Increased intracellular calcium concentration caused by enhanced ATP production
C. Decreased extracellular potassium concentration
D. Increased synthesis of membrane phospholipids
🔴 Correct Answer: A. Increased intracellular sodium concentration.
🔵 Explanation: The sodium-potassium ATPase normally transports three Na⁺ ions out of
the cell and two K⁺ ions into the cell using ATP. Inhibition causes intracellular Na⁺ to
accumulate and disrupts the electrochemical gradients that contribute to resting
membrane potential.
Question 3
A mutation changes a codon in an mRNA molecule from UAU to UAA. Which outcome
is most likely?
A. The mutation causes insertion of an additional amino acid
B. The mutation changes one amino acid into another
C. The mutation creates a premature termination signal
D. The mutation has no possible effect because all codons encode amino acids
🔴 Correct Answer: C. The mutation creates a premature termination signal.
🔵 Explanation: UAU encodes tyrosine, whereas UAA is a stop codon. Conversion of UAU
to UAA therefore creates a nonsense mutation that can terminate translation prematurely
and produce a truncated protein.
Question 4
,A student places identical plant cells into three solutions. Cells placed in solution X
become swollen, cells in solution Y remain approximately unchanged, and cells in
solution Z become plasmolyzed. Which classification is most consistent with these
observations?
A. X is hypertonic, Y is hypotonic, and Z is isotonic
B. X is hypotonic, Y is isotonic, and Z is hypertonic
C. X is isotonic, Y is hypertonic, and Z is hypotonic
D. X is hypertonic, Y is isotonic, and Z is hypotonic
🔴 Correct Answer: B. X is hypotonic, Y is isotonic, and Z is hypertonic.
🔵 Explanation: Water enters cells in a hypotonic environment, producing swelling. An
isotonic environment causes no substantial net water movement. A hypertonic
environment draws water out of cells and can cause plant cells to plasmolyze.
Question 5
A patient has damage to the alveolar-capillary membrane that substantially increases
its thickness. Which change would most directly reduce oxygen transfer from the
alveoli into pulmonary capillary blood?
A. Increased oxygen partial pressure in the alveoli
B. Decreased diffusion distance across the respiratory membrane
C. Increased diffusion distance across the respiratory membrane
D. Increased hemoglobin concentration in erythrocytes
🔴 Correct Answer: C. Increased diffusion distance across the respiratory membrane.
🔵 Explanation: According to principles governing diffusion, increasing membrane
thickness increases diffusion distance and decreases the rate of gas transfer. Although
hemoglobin concentration can influence oxygen-carrying capacity, it does not directly
correct impaired diffusion across a thickened membrane.
Question 6
A researcher measures enzyme activity at progressively increasing temperatures.
Activity rises until 37°C and then rapidly declines as temperature continues increasing.
Which explanation best accounts for the decline?
A. The substrate becomes permanently unavailable at temperatures above 37°C
B. Increased temperature necessarily reduces molecular collisions
, C. Excessive heat disrupts the enzyme's three-dimensional structure
D. The enzyme begins converting all substrates into inhibitors
🔴 Correct Answer: C. Excessive heat disrupts the enzyme's three-dimensional
structure.
🔵 Explanation: Enzymes depend on a specific three-dimensional conformation for
catalytic activity. Temperatures above an enzyme's optimal range can disrupt noncovalent
interactions that maintain its structure, altering the active site and reducing catalytic
activity.
Question 7
A person has type O-negative blood and requires an emergency red blood cell
transfusion when the patient's blood type cannot immediately be determined. Why can
O-negative packed red blood cells generally be used in this situation?
A. They contain both A and B antigens but lack Rh antibodies
B. Their erythrocytes lack A, B, and Rh(D) antigens
C. They contain anti-A and anti-B antigens instead of antibodies
D. They suppress the recipient's adaptive immune response
🔴 Correct Answer: B. Their erythrocytes lack A, B, and Rh(D) antigens.
🔵 Explanation: O-negative erythrocytes lack A, B, and Rh(D) surface antigens, reducing
the likelihood that naturally occurring recipient antibodies will recognize and attack the
transfused red blood cells. This is why O-negative packed cells are commonly considered
the universal donor type for red blood cells.
Question 8
A patient has a deficiency of pancreatic bicarbonate secretion into the duodenum.
Which digestive consequence would most directly result?
A. Increased gastric acid neutralization
B. Reduced activity of pancreatic enzymes that function optimally near neutral or
alkaline pH
C. Increased pepsin activity throughout the small intestine
D. Increased absorption of intact dietary proteins
🔴 Correct Answer: B. Reduced activity of pancreatic enzymes that function
optimally near neutral or alkaline pH.
