HESI A2 Study Guide: Comprehensive Prep for Your Nursing Exam

Correct Answer: C

Rationale: The cell membrane is composed of a phospholipid bilayer with proteins, cholesterol, and glycoproteins. This structure results in the creation of a hydrophobic region between the lipid layers. The cell membrane is termed 'selectively permeable' because it allows certain substances to pass through while restricting the passage of others, based on factors like size and charge. This property is essential for regulating the transport of ions and molecules in and out of the cell to maintain cellular function and homeostasis.

Correct Answer: B

Rationale: Strep throat is caused by the bacterium Streptococcus pyogenes. Unlike mumps, which is a viral infection, AIDS caused by the HIV virus, and the common cold usually caused by rhinoviruses, strep throat is specifically a bacterial infection that can be treated with antibiotics.

Correct Answer: A

Rationale: The flagellum is a whip-like appendage found in certain cells like sperm cells and some bacteria, enabling them to move through their environments. It plays a crucial role in locomotion by allowing cells to swim or propel themselves in liquids, aiding in their movement and navigation.

Correct Answer: A

Rationale: Sex cells, also known as gametes, undergo the process of meiosis to reproduce. Meiosis is a specialized type of cell division that reduces the chromosome number by half, resulting in the formation of four genetically diverse haploid cells from a diploid cell. This reduction is essential for sexual reproduction to ensure genetic diversity in the offspring.

Correct Answer: C

Rationale: In a hypertonic solution, the concentration of solutes is higher compared to the cell's interior. This causes water to move out of the cell to balance the solute concentrations, resulting in the cell shrinking. Therefore, the correct answer is that the solute concentration is higher in a hypertonic solution than inside the cell.