HESI A2 Biology Practice Test

Correct Answer: D

Rationale: Cytokinesis occurs to physically separate the two daughter cells after cell division. This process ensures that each daughter cell receives a complete set of organelles and genetic material. The correct answer, choice D, states that daughter cells can divide, which aligns with the purpose of cytokinesis. Choices A and B are incorrect as they do not directly relate to the process of cytokinesis. Choice C is also incorrect as cytokinesis is not primarily involved in killing bacteria, but rather in ensuring successful cell division.

Correct Answer: A

Rationale: The correct answer is A: DNA-RNA-protein. This process is known as protein synthesis or gene expression. It starts with DNA being transcribed into RNA by RNA polymerase. The RNA then undergoes translation, where ribosomes read the RNA sequence and assemble amino acids into a protein. Choice B is incorrect because genes are segments of DNA, not chromosomes. Choice C is incorrect because ATP is not involved in protein synthesis. Choice D is incorrect because RNA is transcribed from DNA, not the other way around.

Correct Answer: D

Rationale: The correct answer is D because phenotype is the observable characteristics resulting from the interaction between genotype, epigenetic factors, and environmental factors. Genotype (genetic makeup) provides the foundation, epigenetic factors can modify gene expression, and environmental factors play a crucial role in shaping the final phenotype. Explanation: A: Incorrect. Phenotype is not the genetic code itself but the physical expression of genetic traits. B: Incorrect. Phenotype does not determine genotype; genotype determines phenotype. C: Incorrect. Genotype determines phenotype, not the other way around. D: Correct. Genotype, epigenetic factors, and environmental factors collectively determine the phenotype, making it the most comprehensive and accurate choice.

Correct Answer: B

Rationale: The correct answer is B because animal cells do not use chloroplasts to gain energy, they use mitochondria for cellular respiration. Lysosomes in animal cells break down old cells (A) and plant cells have a cell wall (C). Choice D is incorrect as B is false.

Correct Answer: D

Rationale: The correct answer is D: Biomes. Biomes are large geographical areas characterized by specific climate, vegetation, and animal life. Tundra, savannas, grasslands, deserts, and rainforests are all examples of biomes. They are classified based on factors like temperature, precipitation, and flora/fauna. Biomasses (A) refer to the total mass of living organisms in a given area. Biospheres (B) are the regions of the Earth where life exists. Biodiversity (C) refers to the variety and variability of life forms in a specific habitat, not the specific types of habitats themselves.