HESI A2
HESI A2 Practice Test Biology Questions
Question 1 of 5
What is the function of water in photosynthesis?
Correct Answer: C
Rationale: The correct answer is C: 'Supply electrons in the light reactions.' In photosynthesis, water is split during the light reactions of photosynthesis, releasing electrons that are used in the formation of ATP and NADPH, crucial for the synthesis of glucose. Choice A is incorrect because water does not combine with carbon dioxide in photosynthesis. Choice B is incorrect as water does not absorb light energy directly. Choice D is incorrect because the transportation of hydrogen ions mainly occurs in the electron transport chain, which is part of the light reactions, not the dark reactions.
Question 2 of 5
Which of the following describes how a bacterium reproduces?
Correct Answer: C
Rationale: Bacteria reproduce through a process called 'binary fission.' During binary fission, a bacterium duplicates its DNA and then divides into two identical daughter cells. This method is the primary way bacteria replicate. Choice A, 'Mitosis,' is incorrect because mitosis is a process specific to eukaryotic cells, where the nucleus divides to produce two identical nuclei. Choice B, 'Meiosis,' is incorrect as meiosis is a specialized type of cell division that produces gametes with half the chromosome number. Choice D, 'Cytokinesis,' is not the correct answer as cytokinesis is the physical process of cell division, which occurs after the genetic material has been divided in mitosis or meiosis.
Question 3 of 5
Why is DNA important for metabolic activities of the cell?
Correct Answer: A
Rationale: The correct answer is A. DNA plays a crucial role in metabolic activities by controlling the synthesis of enzymes. Enzymes are the biological catalysts that regulate and facilitate metabolic reactions within the cell. Choice B is incorrect because DNA is not involved in stabilizing the cell wall; that role is usually associated with other components like the cell membrane. Choice C is incorrect as cell division is primarily regulated by different processes and molecules, not directly by DNA. Choice D is incorrect because DNA is not related to preventing the diffusion of nutrients; instead, it is involved in coding for proteins that aid in various cellular functions.
Question 4 of 5
Which organelle is responsible for organizing protein synthesis?
Correct Answer: B
Rationale: The correct answer is B: Ribosome. Ribosomes are responsible for organizing protein synthesis by assembling amino acids. They are the cellular machinery where proteins are synthesized. The other choices, such as the nucleus, lysosome, and vacuole, do not directly participate in protein synthesis. The nucleus contains DNA and controls cell activities, the lysosome is involved in digestion and waste removal, and the vacuole is responsible for storage and maintaining cell turgor pressure.
Question 5 of 5
During protein synthesis, what process creates a complementary strand of RNA from a DNA template?
Correct Answer: A
Rationale: The correct answer is 'Transcription.' During protein synthesis, transcription is the process that creates a complementary RNA strand from a DNA template. This process involves the synthesis of mRNA using DNA as a template. Choice B, 'Translation,' is incorrect as it is the process where the genetic code carried by mRNA is decoded to produce a specific polypeptide chain. Choice C, 'Transformation,' is not related to the synthesis of RNA from a DNA template. Choice D, 'Replication,' is the process of copying DNA to produce an identical DNA molecule, not RNA.