Nursing Elites

1. In endocrine regulation, the feedback loop is a critical concept. In a negative feedback loop, high levels of a hormone can result in:

• A. Further stimulating the release of the same hormone
• B. Inhibiting the release of the hormone or its production
• C. Having no effect on the hormone's regulation
• D. Increasing the need for another hormone entirely

Correct answer: B

Rationale: In a negative feedback loop, high levels of a hormone will inhibit the release of the hormone or its production. This mechanism is crucial for maintaining homeostasis by preventing excessive levels of hormones in the body. When a hormone reaches a certain concentration, it triggers the body to decrease its production or release, thereby ensuring a balance within the system. Choice A is incorrect because a negative feedback loop aims to counteract high hormone levels, not further stimulate them. Choice C is incorrect as high hormone levels do have an effect by triggering the feedback loop. Choice D is incorrect as the negative feedback loop operates within the same hormone system rather than increasing the need for an entirely different hormone.

2. How do killer T cells recognize infected cells?

• A. The B cells flag the infected cells with amino acids.
• B. Tiny bits of the virus's RNA are left around the cell.
• C. Macrophages show up to help consume the infected cell.
• D. The T cells have receptors that recognize the proteins the virus leaves on the surface of the cell.

Correct answer: D

Rationale: Killer T cells recognize infected cells by detecting viral proteins displayed on the surface of these cells. The T cells possess receptors specifically designed to identify these viral proteins, allowing them to target and eliminate the infected cells. Choice A is incorrect because B cells are not directly involved in the recognition process of infected cells by killer T cells. Choice B is incorrect because tiny bits of the virus's RNA being left around the cell is not how killer T cells primarily recognize infected cells. Choice C is incorrect because while macrophages play a role in immune responses, they do not directly assist in the recognition of infected cells by killer T cells.

3. Where does cellular respiration, the process of converting chemical energy into ATP, take place in eukaryotic cells?

• A. Nucleus
• B. Ribosomes
• C. Mitochondria
• D. Golgi apparatus

Correct answer: C

Rationale: Cellular respiration, the process of converting chemical energy into ATP, takes place in the mitochondria of eukaryotic cells. The mitochondria are known as the powerhouse of the cell because they are responsible for generating most of the cell's ATP through the process of cellular respiration. This process involves the breakdown of glucose and other organic molecules to produce ATP, which is the primary energy currency of the cell. The other organelles listed in the options (nucleus, ribosomes, and Golgi apparatus) do not play a direct role in cellular respiration. The nucleus is responsible for storing genetic material, ribosomes are involved in protein synthesis, and the Golgi apparatus is involved in processing and packaging proteins for secretion or internal use.

4. What is the term for a genetic disorder caused by a mutation on the X chromosome?

• A. Autosomal dominant disorder
• B. Autosomal recessive disorder
• C. Sex-linked recessive disorder
• D. Sex-linked dominant disorder

Correct answer: C

Rationale: A genetic disorder caused by a mutation on the X chromosome is termed a sex-linked recessive disorder (Option C). This type of disorder is more commonly seen in males due to their single X chromosome, making them more vulnerable to X-linked mutations. Females have two X chromosomes, providing a protective effect against X-linked disorders.\n- Autosomal dominant disorders (Option A) result from a mutation in one copy of a gene on non-sex chromosomes (autosomes) and are not specifically related to the X chromosome.\n- Autosomal recessive disorders (Option B) occur due to mutations in both copies of a gene on autosomes, not on the X chromosome.\n- Sex-linked dominant disorders (Option D) are rare and lead to more severe symptoms in males as they only require one copy of the mutated gene on the X chromosome to express the disorder. However, this is not the term for a genetic disorder caused by an X chromosome mutation.

5. Which of the following is NOT a function of the skeletal system?

• A. Support and structure
• B. Production of red blood cells
• C. Storage of minerals like calcium
• D. Insulation of the body

Correct answer: D

Rationale: The skeletal system's primary functions include support and structure, protection of internal organs, movement facilitation, production of blood cells, and storage of minerals like calcium. Insulation of the body is not a function of the skeletal system. Insulation, typically involving fat under the skin, helps regulate body temperature but is not a direct function of the skeletal system. Choice B, the production of red blood cells, is a function of the skeletal system as it occurs in the bone marrow within the bones. Choices A and C are also correct functions of the skeletal system.

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