Nursing Elites

1. The human immunodeficiency virus (HIV) targets and destroys which type of immune cell?

• A. Neutrophils
• B. Macrophages
• C. Helper T cells
• D. Memory B cells

Correct answer: A

Rationale: The correct answer is C: Helper T cells. HIV targets and destroys Helper T cells, which are a crucial component of the immune system responsible for coordinating the immune response. Neutrophils and macrophages are also important immune cells, but they are not the primary target of HIV. Memory B cells are responsible for mounting a rapid response upon re-exposure to a pathogen but are not the main target of HIV. Thus, HIV primarily affects Helper T cells, leading to the weakening of the immune system and the development of acquired immunodeficiency syndrome (AIDS).

2. The spleen, an organ associated with the lymphatic system, plays a crucial role in:

• A. Regulating blood sugar levels
• B. Filtering blood and destroying old red blood cells
• C. Producing digestive enzymes
• D. Secreting hormones

Correct answer: B

Rationale: The correct answer is B: 'Filtering blood and destroying old red blood cells.' The spleen is part of the lymphatic system and acts as a blood filter, removing old or damaged red blood cells and helping to fight infections. It does not play a role in regulating blood sugar levels (A), producing digestive enzymes (C), or secreting hormones (D). Understanding the function of the spleen in filtering blood and removing old red blood cells is crucial for grasping its role in maintaining overall health and immunity.

3. Which type of isomerism arises due to differences in the arrangement of atoms around a double bond?

• A. Chain isomerism
• B. Functional group isomerism
• C. Cis-trans isomerism
• D. Stereoisomerism

Correct answer: C

Rationale: The correct answer is C: Cis-trans isomerism. Cis-trans isomerism, also known as geometric isomerism, arises due to differences in the spatial arrangement of atoms around a double bond. In cis isomers, similar groups are on the same side of the double bond, while in trans isomers, similar groups are on opposite sides. This type of isomerism is specific to compounds with restricted rotation around a double bond, leading to distinct spatial arrangements and different properties. Chain isomerism (A) refers to isomers with different carbon chain arrangements, functional group isomerism (B) involves different functional groups, and stereoisomerism (D) encompasses all isomers that have the same connectivity but differ in spatial arrangement.

4. Which part of the spinal cord is responsible for transmitting sensory information from the body to the brain?

• A. Dorsal root
• B. Ventral root
• C. Gray matter
• D. White matter

Correct answer: a

Rationale: The correct answer is A: Dorsal root. The dorsal root of the spinal cord is responsible for transmitting sensory information from the body to the brain. This root contains sensory nerve fibers that carry information such as touch, temperature, and pain signals from the peripheral nervous system to the central nervous system. Ventral roots, on the other hand, are responsible for transmitting motor information from the brain to the muscles. Gray matter is primarily composed of nerve cell bodies and is involved in processing information, while white matter consists of myelinated nerve fibers that facilitate communication between different parts of the nervous system. Therefore, in this context, the dorsal root is the specific structure that handles sensory information transmission.

5. How do isotopes affect the atomic mass of an element?

• A. Isotopes have no effect on the atomic mass of an element.
• B. Isotopes cause the atomic mass of an element to vary slightly.
• C. Isotopes cause the atomic mass of an element to be exactly the same for all isotopes of that element.
• D. Isotopes cause the atomic mass of an element to vary greatly.

Correct answer: B

Rationale: The atomic mass of an element is the average mass of all the isotopes of that element. Since isotopes have different numbers of neutrons, they also have slightly different masses. This variation in mass is what causes the atomic mass of an element to be a decimal number, rather than a whole number.

6. Homologous structures are those that:

• A. Have the same function but different origins
• B. Have different functions but the same origin
• C. Are similar in appearance and function due to shared ancestry
• D. Are identical in both appearance and function

Correct answer: C

Rationale: Rationale: - Option A is incorrect because structures with the same function but different origins are analogous structures, not homologous structures. - Option B is incorrect because structures with different functions but the same origin are also not homologous structures; they are considered to be vestigial structures. - Option D is incorrect because structures that are identical in both appearance and function are not necessarily homologous; they could be the result of convergent evolution. Homologous structures are those that share similarities in appearance and function due to being inherited from a common ancestor. These structures may have undergone modifications over time to adapt to different functions in different species, but their fundamental similarities can be traced back to a shared evolutionary history.

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