Nursing Elites

1. What functional group is present in ethers?

• A. Hydroxyl
• B. Carbonyl
• C. Ether
• D. Amine

Correct answer: C

Rationale: The functional group present in ethers is -O-, representing an oxygen atom bonded to two alkyl or aryl groups. Therefore, choice C, 'Ether,' is the correct answer. Choices A, B, and D refer to different functional groups: hydroxyl (-OH), carbonyl (C=O), and amine (NH2), respectively, which are not present in ethers. Ethers are characterized by the oxygen atom bonded to two carbon groups, distinguishing them from the other functional groups mentioned in the choices.

2. Which of the following is an example of a commensal relationship between a microorganism and a human?

• A. Salmonella causing food poisoning
• B. taphylococcus aureus causing skin infections
• C. coli living in the gut
• D. Rabies virus causing neurological disease

Correct answer: C

Rationale: A commensal relationship is a type of symbiotic relationship in which one organism benefits, while the other is neither harmed nor benefited. In this case, E. coli living in the gut is an example of a commensal relationship because it can benefit from the environment in the gut without causing harm to the human host. Option A, Salmonella causing food poisoning, is an example of a pathogenic relationship where the microorganism causes harm to the host. Option B, Staphylococcus aureus causing skin infections, is also an example of a pathogenic relationship where the microorganism causes harm to the host. Option D, Rabies virus causing neurological disease, is another example of a pathogenic relationship where the microorganism causes harm to the host.

3. Which of the following is a unit of work and energy?

• A. Pascal (Pa)
• B. Kilowatt-hour (kWh)
• C. Coulomb (C)
• D. Tesla (T)

Correct answer: B

Rationale: The correct answer is 'B: Kilowatt-hour (kWh).' The kilowatt-hour is a unit commonly used to measure electricity consumption, representing energy usage over time. A Pascal (Pa) is a unit of pressure, Coulomb (C) is a unit of electric charge, and Tesla (T) is a unit of magnetic flux density. Therefore, the kilowatt-hour is the appropriate unit for measuring work and energy in this context.

4. Which of the following correctly identifies a difference between the primary and secondary immune response?

• A. In the secondary response, macrophages migrate to the lymph nodes to present the foreign microorganism to helper T lymphocytes.
• B. The humoral immunity that characterizes the primary response is coordinated by B lymphocytes.
• C. The primary response is quicker and more powerful than the secondary response.
• D. Suppressor T cells are activated in the secondary response to prevent an overactive immune response.

Correct answer: C

Rationale: The correct answer is C. The primary immune response is slower and less powerful compared to the secondary immune response. During the primary response, immune cells encounter the antigen for the first time, necessitating the activation and proliferation of specific immune cells. In contrast, the secondary response benefits from memory cells that quickly recognize the antigen, enabling a faster and more potent immune response. Choices A, B, and D are incorrect. While macrophages play a role in presenting antigens to T cells, this is not a defining difference between primary and secondary responses. Humoral immunity involves B lymphocytes in both primary and secondary responses, so it does not differentiate the two. Suppressor T cells primarily function to regulate the immune response but are not a key factor distinguishing primary from secondary responses.

5. Adaptive radiation refers to the evolutionary process where:

• A. A single ancestral species diversifies into multiple descendant species due to ecological pressures in a heterogeneous environment.
• B. Two unrelated species evolve similar adaptations in response to similar environments, leading to convergent evolution.
• C. A population becomes increasingly well-adapted to its current environment through continued natural selection.
• D. The fossil record exhibits gaps or missing links in the evolutionary history of a lineage.

Correct answer: A

Rationale: - Adaptive radiation is a process where a single ancestral species diversifies into multiple descendant species to exploit different ecological niches within a heterogeneous environment. - This diversification occurs due to the different selective pressures present in various habitats, leading to the evolution of distinct traits and adaptations in different descendant species. - Option A accurately describes the process of adaptive radiation, where the initial species undergoes rapid speciation to occupy different ecological roles and adapt to diverse environmental conditions. - Options B, C, and D do not accurately describe adaptive radiation but refer to other evolutionary processes such as convergent evolution, natural selection, and gaps in the fossil record, respectively.

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