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: Propulsion. This is because propulsion refers to the act of driving or moving something forward, which is exactly what propels the cell forward. Microfilaments (choice A) are involved in providing structural support and movement within the cell, but they do not directly propel the cell forward. Cilia (choice C) and flagella (choice D) are external structures that can help with cell movement, but they do not serve as the primary driving force behind the cell's forward movement. Therefore, choice B is the correct answer as it directly relates to the action of moving the cell forward.

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.

Correct Answer: B

Rationale: The correct answer is B: 23 pairs. Humans have a total of 46 chromosomes, with 23 pairs. This is because we inherit one set of 23 chromosomes from each parent. Each pair consists of one chromosome from the mother and one from the father. Choices A, C, and D are incorrect because they do not align with the established fact that humans have 23 pairs of chromosomes. It's crucial to understand the basics of human genetics to grasp the correct answer in this case.

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.