Review these Biology Hesi A2 Practice Set nursing practice questions with answer choices and explanations.
A researcher finds ribosomes both free in cytosol and attached to a membrane system. Which system is it?
Correct answer:
Explanation: Ribosomes can be free or attached to rough endoplasmic reticulum, where many secreted and membrane proteins begin synthesis.
What type of bond joins oxygen to hydrogen within one water molecule?
Correct answer:
Explanation: Oxygen attracts the shared electrons more strongly, making the covalent bonds polar.
A pancreatic cell releases a digestive enzyme. Which route is most appropriate for that protein?
Correct answer:
Explanation: Secreted proteins commonly pass through rough ER, the Golgi, and vesicles before release.
Why do many skeletal muscle cells contain numerous mitochondria?
Correct answer:
Explanation: Mitochondria support the energy demands of repeated muscle contraction.
A substance can enter a cell only after binding a specific carrier. What does this illustrate?
Correct answer:
Explanation: Transport proteins recognize particular substances, helping regulate membrane passage.
What is the principal location of most extracellular fluid?
Correct answer:
Explanation: Extracellular fluid includes fluid between cells and the liquid part of blood.
Which ion is normally more concentrated inside most human cells than outside them?
Correct answer:
Explanation: Cells maintain relatively high intracellular potassium through membrane transport mechanisms.
Which event releases energy that a cell can couple to active transport?
Correct answer:
Explanation: ATP breakdown can power transport proteins that move substances against gradients.
Which anatomical plane divides the body into upper and lower portions?
Correct answer:
Explanation: A transverse plane separates superior and inferior portions.
Which anatomical plane divides the body into front and back portions?
Correct answer:
Explanation: A frontal, or coronal, plane separates anterior and posterior portions.
The wrist is farther from the shoulder than the elbow is. Which term describes this position?
Correct answer:
Explanation: Distal means farther from the point of attachment or origin.
Which term describes a structure nearer the body's surface?
Correct answer:
Explanation: Superficial refers to proximity to the external surface.
Which organ is protected primarily by the cranial cavity?
Correct answer:
Explanation: The skull encloses the brain within the cranial cavity.
Which organ lies mainly in the pelvic cavity?
Correct answer:
Explanation: The bladder sits in the pelvis and stores urine.
Which heart chamber first receives blood returning from most body tissues?
Correct answer:
Explanation: The venae cavae return systemic venous blood to the right atrium.
Which vessel is the main artery leaving the left ventricle?
Correct answer:
Explanation: The aorta distributes blood from the left ventricle to the systemic circulation.
Why do many veins in the limbs contain valves?
Correct answer:
Explanation: Venous valves support one-way return toward the heart, particularly against gravity.
Which structure connects the throat region to the bronchi and conducts air?
Correct answer:
Explanation: The trachea is an airway that branches into the main bronchi.
Which organ performs most chemical processing of absorbed nutrients and many drugs?
Correct answer:
Explanation: The liver has major roles in metabolism, nutrient handling, and chemical modification.
What is an essential amino acid?
Correct answer:
Explanation: The body cannot synthesize essential amino acids in sufficient amounts to meet its needs.
Which dietary nutrient supplies approximately 9 kilocalories per gram?
Correct answer:
Explanation: Fat provides about nine kilocalories per gram, compared with about four for protein and carbohydrate.
Which pair of nutrients each provides approximately 4 kilocalories per gram?
Correct answer:
Explanation: Protein and digestible carbohydrate each supply roughly four kilocalories per gram.
Which vitamin is water-soluble?
Correct answer:
Explanation: B vitamins and vitamin C are water-soluble; vitamins A, D, E, and K are fat-soluble.
Which group contains only fat-soluble vitamins?
Correct answer:
Explanation: The four fat-soluble vitamins are A, D, E, and K.
Which mineral contributes substantially to the hardness of bones and teeth?
Correct answer:
Explanation: Calcium salts, together with phosphate, mineralize bones and teeth.
A recessive trait appears only in aa individuals. Which genotype would express it?
Correct answer:
Explanation: In complete dominance, two recessive alleles are required to express the recessive phenotype.
For a simple dominant trait, what fraction of offspring from Aa crossed with aa is expected to show the dominant phenotype?
Correct answer:
Explanation: Half the expected offspring are Aa and half aa.
Why does DNA need to be copied before a typical body cell divides?
Correct answer:
Explanation: Replication supplies chromosome copies that can be distributed to both daughters.
What is one important function of messenger RNA?
Correct answer:
Explanation: Messenger RNA provides the template read during translation.
A base substitution changes a codon so that a different amino acid is inserted. What is this called?
Correct answer:
Explanation: A missense mutation changes the amino acid specified by a coding sequence.
Which fluid helps trap inhaled particles in the respiratory tract?
Correct answer:
Explanation: Mucus traps material that can then be cleared by cilia and coughing.
Which enzyme in tears and saliva can damage bacterial cell walls?
Correct answer:
Explanation: Lysozyme breaks bonds in peptidoglycan and contributes to innate defense.
Which immune response is generally more specific for a particular antigen?
Correct answer:
Explanation: Adaptive responses involve lymphocytes with antigen-specific recognition.
A harmless substance triggers an excessive immune response. What is this commonly called?
Correct answer:
Explanation: An allergy is an inappropriate immune response to an ordinarily harmless antigen.
Why is an intact skin surface important for infection prevention?
Correct answer:
Explanation: Skin restricts access to underlying tissues and forms part of innate defense.
A researcher finds ribosomes both free in cytosol and attached to a membrane system. Which system is it?
Correct answer:
Explanation: Ribosomes can be free or attached to rough endoplasmic reticulum, where many secreted and membrane proteins begin synthesis.
What type of bond joins oxygen to hydrogen within one water molecule?
Correct answer:
Explanation: Oxygen attracts the shared electrons more strongly, making the covalent bonds polar.
A pancreatic cell releases a digestive enzyme. Which route is most appropriate for that protein?
Correct answer:
Explanation: Secreted proteins commonly pass through rough ER, the Golgi, and vesicles before release.
Why do many skeletal muscle cells contain numerous mitochondria?
Correct answer:
Explanation: Mitochondria support the energy demands of repeated muscle contraction.
A substance can enter a cell only after binding a specific carrier. What does this illustrate?
Correct answer:
Explanation: Transport proteins recognize particular substances, helping regulate membrane passage.
What is the principal location of most extracellular fluid?
Correct answer:
Explanation: Extracellular fluid includes fluid between cells and the liquid part of blood.
Which ion is normally more concentrated inside most human cells than outside them?
Correct answer:
Explanation: Cells maintain relatively high intracellular potassium through membrane transport mechanisms.
Which event releases energy that a cell can couple to active transport?
Correct answer:
Explanation: ATP breakdown can power transport proteins that move substances against gradients.
Which anatomical plane divides the body into upper and lower portions?
Correct answer:
Explanation: A transverse plane separates superior and inferior portions.
Which anatomical plane divides the body into front and back portions?
Correct answer:
Explanation: A frontal, or coronal, plane separates anterior and posterior portions.
The wrist is farther from the shoulder than the elbow is. Which term describes this position?
Correct answer:
Explanation: Distal means farther from the point of attachment or origin.
Which term describes a structure nearer the body's surface?
Correct answer:
Explanation: Superficial refers to proximity to the external surface.
Which organ is protected primarily by the cranial cavity?
Correct answer:
Explanation: The skull encloses the brain within the cranial cavity.
Which organ lies mainly in the pelvic cavity?
Correct answer:
Explanation: The bladder sits in the pelvis and stores urine.
Which heart chamber first receives blood returning from most body tissues?
Correct answer:
Explanation: The venae cavae return systemic venous blood to the right atrium.
Which vessel is the main artery leaving the left ventricle?
Correct answer:
Explanation: The aorta distributes blood from the left ventricle to the systemic circulation.
Why do many veins in the limbs contain valves?
Correct answer:
Explanation: Venous valves support one-way return toward the heart, particularly against gravity.
Which structure connects the throat region to the bronchi and conducts air?
Correct answer:
Explanation: The trachea is an airway that branches into the main bronchi.
Which organ performs most chemical processing of absorbed nutrients and many drugs?
Correct answer:
Explanation: The liver has major roles in metabolism, nutrient handling, and chemical modification.
What is an essential amino acid?
Correct answer:
Explanation: The body cannot synthesize essential amino acids in sufficient amounts to meet its needs.
Which dietary nutrient supplies approximately 9 kilocalories per gram?
Correct answer:
Explanation: Fat provides about nine kilocalories per gram, compared with about four for protein and carbohydrate.
Which pair of nutrients each provides approximately 4 kilocalories per gram?
Correct answer:
Explanation: Protein and digestible carbohydrate each supply roughly four kilocalories per gram.
Which vitamin is water-soluble?
Correct answer:
Explanation: B vitamins and vitamin C are water-soluble; vitamins A, D, E, and K are fat-soluble.
Which group contains only fat-soluble vitamins?
Correct answer:
Explanation: The four fat-soluble vitamins are A, D, E, and K.
Which mineral contributes substantially to the hardness of bones and teeth?
Correct answer:
Explanation: Calcium salts, together with phosphate, mineralize bones and teeth.
A recessive trait appears only in aa individuals. Which genotype would express it?
Correct answer:
Explanation: In complete dominance, two recessive alleles are required to express the recessive phenotype.
For a simple dominant trait, what fraction of offspring from Aa crossed with aa is expected to show the dominant phenotype?
Correct answer:
Explanation: Half the expected offspring are Aa and half aa.
Why does DNA need to be copied before a typical body cell divides?
Correct answer:
Explanation: Replication supplies chromosome copies that can be distributed to both daughters.
What is one important function of messenger RNA?
Correct answer:
Explanation: Messenger RNA provides the template read during translation.
A base substitution changes a codon so that a different amino acid is inserted. What is this called?
Correct answer:
Explanation: A missense mutation changes the amino acid specified by a coding sequence.
Which fluid helps trap inhaled particles in the respiratory tract?
Correct answer:
Explanation: Mucus traps material that can then be cleared by cilia and coughing.
Which enzyme in tears and saliva can damage bacterial cell walls?
Correct answer:
Explanation: Lysozyme breaks bonds in peptidoglycan and contributes to innate defense.
Which immune response is generally more specific for a particular antigen?
Correct answer:
Explanation: Adaptive responses involve lymphocytes with antigen-specific recognition.
A harmless substance triggers an excessive immune response. What is this commonly called?
Correct answer:
Explanation: An allergy is an inappropriate immune response to an ordinarily harmless antigen.
Why is an intact skin surface important for infection prevention?
Correct answer:
Explanation: Skin restricts access to underlying tissues and forms part of innate defense.