Nursing Elites

1. In a covalent bond, the shared electrons:

• A. Are completely transferred to one atom.
• B. Spend more time closer to the more electronegative atom.
• C. Remain equidistant between the two atoms.
• D. Do not influence the bond strength.

Correct answer: B

Rationale: Spend more time closer to the more electronegative atom. Electronegativity determines the "pull" on shared electrons, with the more electronegative atom attracting them for a larger portion of the time, creating a partial negative charge near its nucleus.

2. The kidneys are bean-shaped organs that perform several vital functions. Which of the following is NOT a primary function of the kidneys?

• A. Filtering waste products from the blood
• B. Regulating blood pressure
• C. Producing red blood cells
• D. Maintaining water balance in the body

Correct answer: C

Rationale: The correct answer is C. While the kidneys perform multiple vital functions, such as filtering waste products from the blood, regulating blood pressure, and maintaining water balance in the body, they do not produce red blood cells. Red blood cell production occurs in the bone marrow, specifically in the spongy tissue called the red bone marrow. Therefore, the kidneys' primary functions do not include producing red blood cells.

3. Which of the following is a redox reaction?

• A. 2H2 + O2 → 2H2O
• B. Zn + 2HCl → ZnCl2 + H2
• C. 2NaCl → 2Na + Cl2
• D. CH4 + 2O2 → CO2 + 2H2O

Correct answer: b

Rationale: The oxidation state of Zn changes from 0 to +2, indicating a redox reaction.

4. Which of the following is NOT a characteristic of mitosis?

• A. The replication of DNA
• B. The condensation of chromosomes
• C. The separation of sister chromatids
• D. The formation of haploid cells

Correct answer: D

Rationale: Rationale: A) The replication of DNA is a characteristic of mitosis. Before cell division occurs, the DNA is replicated to ensure that each daughter cell receives a complete set of genetic information. B) The condensation of chromosomes is a characteristic of mitosis. During mitosis, the chromosomes condense and become visible under a microscope as distinct structures. C) The separation of sister chromatids is a crucial step in mitosis. During anaphase, the sister chromatids are pulled apart and move to opposite poles of the cell to ensure that each daughter cell receives a complete set of chromosomes. D) The formation of haploid cells is NOT a characteristic of mitosis. Mitosis results in the formation of two identical diploid daughter cells, each containing the same number of chromosomes as the parent cell. Haploid cells are typically formed through the process of meiosis, not mitosis.

5. What is the role of DNA in evolution?

• A. It stores genetic information that can be passed on to offspring
• B. It allows for mutations that can introduce new variations
• C. It regulates the expression of genes that influence traits
• D. All of the above

Correct answer: D

Rationale: Rationale: A) DNA stores genetic information that is passed on from parents to offspring through the process of reproduction. This genetic information contains instructions for the development and functioning of an organism. B) DNA can undergo mutations, which are changes in the genetic sequence. These mutations can introduce new variations in the DNA, leading to genetic diversity within a population. C) DNA plays a crucial role in regulating the expression of genes. Gene expression determines which proteins are produced in an organism, influencing its traits and characteristics. D) Therefore, DNA is involved in all of the above processes, making it a key factor in evolution by driving genetic variation, inheritance, and gene expression.

6. 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: 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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