HESI A2 Study Guide: Comprehensive Prep for Your Nursing Exam

Correct Answer: D

Rationale: The plasma membrane is arranged in a double layer of phospholipids, known as a lipid bilayer. This structure consists of two layers of phospholipid molecules with their hydrophilic (water-attracting) heads facing outwards and their hydrophobic (water-repelling) tails facing inward. This lipid bilayer provides a barrier that separates the interior of the cell from the external environment, regulating the passage of substances in and out of the cell.

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.