Biology HESI A2 Practice Test

Correct Answer: C

Rationale: The correct answer is C. Antibiotics do not cause more bacteria to grow; in fact, they aim to kill or inhibit the growth of bacteria. Antibiotics interfere with the bacteria's ability to survive by targeting specific processes essential for their growth and reproduction (A). They can affect how bacteria multiply by inhibiting cell wall synthesis, protein synthesis, or DNA replication (B). Lastly, antibiotics specifically target bacteria and do not work on viruses or fungi (D). Therefore, choice C is the only statement that is not true about antibiotics.

Correct Answer: C

Rationale: The correct answer is C: Uracil. DNA bases consist of Adenine, Thymine, Cytosine, and Guanine, whereas Uracil is only found in RNA. DNA uses Thymine, while RNA uses Uracil as one of its bases. Therefore, Uracil is not a part of DNA bases. Adenine, Thymine, and Cytosine are all essential components of DNA.

Correct Answer: B

Rationale: The correct answer is B: They are haploid cells. Gametes are sex cells (sperm and egg) that contain half the number of chromosomes as somatic cells. This is essential for maintaining the diploid chromosome number during fertilization. Choice A is incorrect because gametes are not diploid, but haploid. Choice C is incorrect because gametes are not somatic cells; somatic cells make up the body tissues and are diploid. Choice D is incorrect because only choice B is true; gametes are haploid, not diploid or somatic.

Correct Answer: A

Rationale: The correct answer is A: hypothesis. A hypothesis is a statement that proposes an explanation for a phenomenon based on available evidence. It helps guide scientific inquiry by providing a testable prediction. Observations (B) are simply data collected through senses. Experiments (C) involve testing hypotheses through controlled conditions. Conclusions (D) are interpretations drawn from the data collected. Therefore, a hypothesis is the initial statement or explanation of certain events or happenings in the scientific process.

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.