Biology HESI A2 Practice Test

Correct Answer: B

Rationale: The correct answer is B: Cell wall. Plant cells have a rigid cell wall made of cellulose, which provides structural support and protection. Animal cells lack cell walls and instead have a flexible cell membrane for support. Choices A, C, and D (Cell membrane, Ribosome, Chloroplast) are present in both plant and animal cells. The cell membrane controls what enters and leaves the cell, ribosomes are responsible for protein synthesis, and chloroplasts are the site of photosynthesis in plant cells.

Correct Answer: B

Rationale: The correct answer is B: They are haploid cells. Gametes are sex cells (sperm and egg) that contain half the number of chromosomes as somatic cells. This is essential for maintaining the diploid chromosome number during fertilization. Choice A is incorrect because gametes are not diploid, but haploid. Choice C is incorrect because gametes are not somatic cells; somatic cells make up the body tissues and are diploid. Choice D is incorrect because only choice B is true; gametes are haploid, not diploid or somatic.

Correct Answer: B

Rationale: The correct answer is B: Tendons, ligaments. Tendons connect muscles to bones, enabling movement. Ligaments connect bones to each other, providing stability. Muscles and ligaments are not directly involved in connecting muscles to bones. Therefore, option B is the most appropriate choice.

Correct Answer: C

Rationale: The correct answer is C: Proteins embedded in lipid bilayer. This arrangement is seen in the plasma membrane based on the fluid mosaic model. The lipid bilayer provides a barrier for the cell, while proteins are embedded within the bilayer, performing various functions like transport, signaling, and structural support. This arrangement allows for selective permeability and communication with the external environment. A: Lipids with embedded proteins - While proteins are indeed embedded in the lipid bilayer, the primary arrangement is not lipids with embedded proteins. B: An outer lipid layer and an inner lipid layer - This describes the structure of the lipid bilayer itself, but it does not address the arrangement of proteins within the membrane. D: Altering protein and lipid layers - This choice does not accurately describe the typical arrangement of proteins and lipids in the plasma membrane.

Correct Answer: B

Rationale: The correct answer is B: mitochondria. Heart muscle cells require a significant amount of energy to constantly contract and pump blood, making mitochondria crucial for energy production through aerobic respiration. Mitochondria are abundant in heart muscle cells to meet their high energy demands. Lysosomes (A) are involved in cellular waste disposal, mRNA (C) carries genetic information, and ribosomes (D) are involved in protein synthesis, but they are not expected to be unusually high in heart muscle cells.