HESI A2 Study Guide: Comprehensive Prep for Your Nursing Exam

Correct Answer: C

Rationale: Rationale: 1. The correct answer is C: Clostridium. 2. Clostridium is a type of bacteria that has a circular structure known as a plasmid. 3. Plasmids are small, circular DNA molecules found in bacteria. 4. Mycobacterium (A) has a rod-shaped structure with a linear chromosome. 5. Actinomyces (B) has a filamentous structure, not circular. 6. Neisseria (D) has a diplococci shape, not circular. In summary, Clostridium fits the criteria of having a circular structure due to its plasmid, making it the correct choice.

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.