Nursing Elites

1. What is the milky-white fluid transported by the lymphatic vessels called?

• A. Plasma
• B. Blood
• C. Chyle
• D. Mucus

Correct answer: C

Rationale: The milky-white fluid transported by the lymphatic vessels is called chyle. Chyle is formed in the small intestine during the digestion of fatty foods and contains a mixture of lymph and emulsified fats. Plasma is the liquid component of blood, not lymphatic fluid. Blood refers to the fluid that circulates in the cardiovascular system, not lymphatic fluid. Mucus is a slimy substance secreted by mucous membranes, not the fluid transported by lymphatic vessels.

2. During which phase of the cell cycle does cytokinesis typically occur?

• A. Interphase
• B. Mitosis
• C. Meiosis
• D. G2 phase

Correct answer: B

Rationale: Cytokinesis is the process of dividing the cytoplasm of a cell into two daughter cells after the nucleus has divided during mitosis. In the cell cycle, cytokinesis typically occurs at the end of the mitotic phase, following the separation of the duplicated chromosomes into two identical sets in the daughter nuclei. Interphase (option A) is the phase where the cell grows, carries out its normal functions, and prepares for cell division, but cytokinesis does not occur during this phase. Meiosis (option C) is a specialized type of cell division that occurs in sexually reproducing organisms to produce gametes, and cytokinesis occurs at the end of meiosis II, not meiosis I. G2 phase (option D) is the phase of the cell cycle following DNA replication in S phase and preceding mitosis, where the cell prepares for cell division, but cytokinesis occurs during mitosis, not in the G2 phase.

3. Which of the following glands is responsible for regulating metabolism?

• A. Thymus
• B. Pituitary
• C. Pancreas
• D. Thyroid

Correct answer: D

Rationale: The correct answer is D, Thyroid. The thyroid gland is responsible for regulating metabolism by producing thyroid hormones. These hormones play a crucial role in controlling various metabolic processes in the body, including energy production and utilization. Choice A, Thymus, is not responsible for regulating metabolism but plays a role in the immune system. Choice B, Pituitary, regulates various hormones but not specifically focused on metabolism. Choice C, Pancreas, is involved in insulin production and blood sugar regulation but is not primarily responsible for regulating metabolism.

4. Which structure allows for the selective passage of materials into and out of the cell?

• A. DNA
• B. Protein
• C. Carbohydrate
• D. Phospholipid bilayer

Correct answer: D

Rationale: The phospholipid bilayer is a crucial component of the cell membrane, surrounding the cell and regulating the passage of materials into and out of the cell. Its structure enables it to be selectively permeable, controlling which substances can pass through. DNA, proteins, and carbohydrates are essential molecules in the cell but do not directly govern the passage of materials like the phospholipid bilayer does. Therefore, the correct answer is the phospholipid bilayer.

5. In an SN2 reaction, what affects the rate of the reaction?

• A. Only the concentration of the nucleophile
• B. Only the concentration of the electrophile
• C. Neither the concentration of the nucleophile nor the electrophile
• D. Both the concentration of the nucleophile and the electrophile

Correct answer: D

Rationale: In an SN2 reaction, the rate of the reaction is affected by both the concentration of the nucleophile and the electrophile. The rate-determining step involves the nucleophile attacking the electrophile, so the concentrations of both species will impact the reaction rate. Increasing the concentration of the nucleophile increases the frequency of nucleophilic attacks, while increasing the concentration of the electrophile provides more opportunities for the nucleophile to react. Therefore, the correct answer is that both the concentration of the nucleophile and the electrophile affect the rate of the SN2 reaction. Choices A, B, and C are incorrect as they do not consider the interplay between the nucleophile and the electrophile in determining the overall reaction rate in an SN2 mechanism.

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