HESI A2 Biology Practice Test 2024

Correct Answer: B

Rationale: The correct answer is B: Cell Membrane. The cell membrane is the most important component contributing to protection, communication, and the passage of substances. It acts as a barrier, protecting the cell from external threats. It also regulates the passage of substances in and out of the cell through selective permeability. Additionally, the cell membrane contains receptors and proteins that facilitate cell communication. A: Cytoplasm is important for various cellular functions but does not directly contribute to protection, communication, or substance passage. C: Cytoskeleton provides structural support but does not primarily contribute to protection, communication, or substance passage. D: Vacuole plays a role in storage and waste management but is not as critical for protection, communication, or substance passage as the cell membrane.

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: C

Rationale: The correct answer is C: Peroxisomes. Peroxisomes are responsible for detoxifying harmful substances in the cell by using enzymes to break down toxic molecules like hydrogen peroxide. This organelle contains catalase, an enzyme that converts hydrogen peroxide into water and oxygen. Endoplasmic Reticulum (choice A) is involved in protein synthesis and lipid metabolism. Lysosomes (choice B) are responsible for breaking down cellular waste and recycling materials. Golgi Apparatus (choice D) is involved in processing and packaging proteins for secretion. Therefore, Peroxisomes specifically handle detoxification, making it the correct choice.

Correct Answer: B

Rationale: The correct answer is B: Lipids. The plasma membrane is primarily composed of lipids, specifically phospholipids, which form a lipid bilayer. This structure provides the membrane with its selective permeability properties. Proteins are also present in the membrane, but they are not the primary composition. Carbohydrates are found on the outer surface of the membrane for cell recognition and signaling. Nucleotides are the building blocks of nucleic acids and are not a major component of the plasma membrane.

Correct Answer: B

Rationale: The correct answer is B: Gametes. Meiosis is the process of cell division that produces gametes (sex cells) such as sperm and eggs. During meiosis, a diploid cell undergoes two rounds of division to produce four haploid gametes. Somatic cells (choice A) are non-reproductive cells in the body. Zygote (choice C) is a fertilized egg formed by the fusion of sperm and egg, not involved in meiosis. Diploid cells (choice D) have two sets of chromosomes and are the starting cells for meiosis, not the end products. Therefore, gametes are the specific cells involved in meiosis.