Biology HESI A2 Practice Test

Correct Answer: A

Rationale: The correct answer is A: Ribosome. Ribosomes are the organelles responsible for protein synthesis in the cell. They can be found in the cytoplasm or attached to the endoplasmic reticulum. Ribosomes read the mRNA and assemble amino acids into proteins through a process called translation. Summary of other choices: B: Chloroplast - responsible for photosynthesis in plant cells. C: Lysosome - contains enzymes for digesting waste materials. D: Mitochondrion - produces ATP through cellular respiration. These organelles are not directly involved in protein synthesis, making them incorrect choices for this question.

Correct Answer: A

Rationale: The correct answer is A because the apical side of an epithelial cell is the top surface that is exposed to fluid or air. This surface is specialized for absorption, secretion, and protection. Choice B is incorrect because the apical side is actually the top side of the cell, not the bottom. Choice C is incorrect because the apical side allows substances to pass through via various transport mechanisms such as active transport, facilitated diffusion, or simple diffusion. Choice D is incorrect because the apical side of an epithelial cell is indeed exposed to fluid or air, making it the correct answer.

Correct Answer: B

Rationale: The correct answer is B because antibiotics are designed to target and kill bacteria, not viruses like the flu. Viruses and bacteria are different types of microorganisms with distinct structures and replication mechanisms. Antibiotics work by disrupting bacterial cell processes, which viruses lack. Therefore, using antibiotics for viral infections like the flu is ineffective. Choice A is incorrect because it refers to a different type of infection, not the reason why antibiotics don't work for the flu. Choice C is incorrect because the issue lies in the antibiotic's ineffectiveness against viruses, not the dosage. Choice D is also incorrect as B clearly explains the reason why antibiotics don't work for treating the flu.

Correct Answer: A

Rationale: The correct answer is A: TGAACGT. To find the matching DNA strand, we need to use complementary base pairing rules: A pairs with T, C pairs with G. Given the segment ACTTGCA, its complementary DNA strand would be TGAACTG. Therefore, the correct answer is A. Option B (GACCATG) is incorrect because it does not follow the complementary base pairing rules. Option C (ACTTGCA) is the same as the original segment given, so it is also incorrect. Option D (None of the above) is incorrect as the correct answer is A.

Correct Answer: C

Rationale: The correct answer is C: Producing blood. The skeletal system does not produce blood; that is the function of the bone marrow within the bones. The other choices are functions of the skeletal system: A) Providing shape and form by supporting soft tissues, B) Supporting and protecting the body by providing structure and protecting internal organs, D) Storing vitamins like calcium and phosphorus for bone health. Thus, option C is the correct answer as it does not directly relate to the functions of the skeletal system.