HESI A2 Biology Practice Test 2024

Correct Answer: B

Rationale: The main function of ribosomes is protein synthesis. Ribosomes are responsible for translating the genetic information encoded in mRNA into proteins. This process involves decoding the mRNA sequence and linking amino acids together to form a protein. Ribosomes do not participate in DNA replication (Choice A), lipid breakdown (Choice C), or cell division (Choice D). DNA replication occurs in the nucleus, lipid breakdown is carried out by enzymes in the cytoplasm, and cell division involves processes such as mitosis and cytokinesis. Therefore, the correct answer is B because ribosomes are directly involved in protein synthesis.

Correct Answer: B

Rationale: The correct answer is B: Krebs Cycle. This cycle, also known as the citric acid cycle, occurs in the mitochondria of cells and plays a crucial role in generating energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. It produces ATP, NADH, and FADH2, which are essential for cellular energy production. The Calvin Cycle (A) and Photosynthesis (C) are involved in the process of converting light energy into chemical energy in plants, not in generating energy during cellular respiration. Fermentation (D) is an anaerobic process that generates energy in the absence of oxygen, but it is not as efficient as aerobic respiration in producing ATP.

Correct Answer: B

Rationale: The main function of ribosomes is protein synthesis. Ribosomes are responsible for translating the genetic information encoded in mRNA into proteins. This process involves decoding the mRNA sequence and linking amino acids together to form a protein. Ribosomes do not participate in DNA replication (Choice A), lipid breakdown (Choice C), or cell division (Choice D). DNA replication occurs in the nucleus, lipid breakdown is carried out by enzymes in the cytoplasm, and cell division involves processes such as mitosis and cytokinesis. Therefore, the correct answer is B because ribosomes are directly involved in protein synthesis.

Correct Answer: B

Rationale: The correct answer is B: Communication. The cell membrane serves as a barrier that regulates the passage of materials in and out of the cell. It also plays a crucial role in cell communication by allowing the exchange of signals and molecules with the external environment and other cells. This communication is essential for coordinating various cellular processes and maintaining homeostasis. Other choices are incorrect: A: Energy production - This function is primarily carried out by organelles such as mitochondria and chloroplasts, not the cell membrane. C: Protein synthesis - Protein synthesis occurs in the ribosomes within the cell, not the cell membrane. D: Waste removal - While the cell membrane does play a role in waste removal by allowing certain materials to exit the cell, it is not its main function.

Correct Answer: A

Rationale: Mitosis is the correct answer because it is the process of cell division in which a single cell divides into two daughter cells that are genetically identical to the parent cell. This process involves several stages such as prophase, metaphase, anaphase, and telophase, where the genetic material is replicated and evenly distributed to the daughter cells. Meiosis, on the other hand, results in four daughter cells with genetic variation, not identical genetic material. Binary fission is a form of asexual reproduction in prokaryotic cells, not eukaryotic cells like mitosis. Budding is a type of asexual reproduction seen in some organisms where a new individual develops as an outgrowth of the parent cell, not resulting in two daughter cells with identical genetic material.