Nursing Elites

1. What is the general formula for an alkene?

• A. CnH2n+2
• B. CnH2n
• C. CnH2n-2
• D. CnH2n+1

Correct answer: B

Rationale: The general formula for an alkene is \(C_nH_{2n}\), indicating the presence of a double bond between carbon atoms.

2. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: The correct answer is A: Schwann cells. Schwann cells are a type of glial cell in the peripheral nervous system that produce the myelin sheath around axons. Myelin sheath is essential for the rapid conduction of nerve impulses and provides insulation and protection to nerve fibers. Astrocytes are glial cells that provide support and maintain homeostasis in the central nervous system, but they do not produce myelin. Neurons are the main functional units of the nervous system responsible for transmitting nerve impulses. Oligodendrocytes are another type of glial cell in the central nervous system that produce myelin sheath around axons in that region, not in the peripheral nervous system where Schwann cells are responsible for myelination.

3. What property of matter refers to the amount of space occupied by an object and is measured in cubic units?

• A. Mass
• B. Density
• C. Weight
• D. Volume

Correct answer: d

Rationale: Volume is the property that refers to the amount of space occupied by an object and is measured in cubic units such as cubic meters or cubic centimeters.

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. Which of the following is NOT a recognized mode of natural selection?

• A. Directional selection (favoring one extreme trait value on a spectrum)
• B. Disruptive selection (favoring both extreme trait values on a spectrum)
• C. Stabilizing selection (favoring the average trait value on a spectrum)
• D. Sexual selection (selection based on mate choice that influences reproductive success)

Correct answer: D

Rationale: Rationale: A) Directional selection is a recognized mode of natural selection where one extreme trait value on a spectrum is favored over others. This can lead to a shift in the average trait value over time. B) Disruptive selection is a recognized mode of natural selection where both extreme trait values on a spectrum are favored over the average trait value. This can lead to the population splitting into two distinct groups. C) Stabilizing selection is a recognized mode of natural selection where the average trait value on a spectrum is favored over extreme values. This can lead to a reduction in genetic diversity within a population. D) Sexual selection is not a mode of natural selection in the traditional sense, as it involves mate choice and competition for mates rather than direct selection pressure on traits that affect survival and reproduction in the environment. Sexual selection can lead to the evolution of traits that enhance an individual's ability to attract

6. What are the finger-like projections that increase the surface area for absorption in the small intestine called?

• A. Crypts of Lieberkühn
• B. Goblet cells
• C. Villi
• D. Paneth cells

Correct answer: C

Rationale: Rationale: A) Crypts of Lieberkühn are small pits in the lining of the small intestine that contain cells involved in the production of intestinal juices, but they do not increase the surface area for absorption. B) Goblet cells are specialized cells that secrete mucus to protect the lining of the digestive tract, but they do not increase the surface area for absorption. C) Villi are finger-like projections in the small intestine that increase the surface area available for nutrient absorption. Each villus contains blood vessels and lacteals (lymphatic vessels) that help absorb nutrients from digested food. D) Paneth cells are specialized cells found in the small intestine that secrete antimicrobial substances, but they do not increase the surface area for absorption.

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