Nursing Elites

1. Which vitamin requires the lymphatic system for proper absorption from the intestine?

• A. Vitamin A
• B. Vitamin C
• C. Vitamin D
• D. Vitamin B12

Correct answer: C

Rationale: The correct answer is Vitamin D. Vitamin D requires the lymphatic system for proper absorption from the intestine. Unlike vitamins A, C, and B12, which are absorbed directly into the bloodstream, vitamin D is absorbed into the lymphatic system first before entering the bloodstream. Therefore, options A, B, and D are incorrect as they do not rely on the lymphatic system for absorption from the intestine.

2. Molecular clocks utilize the accumulation of mutations in DNA sequences to estimate the evolutionary divergence time between species. This method relies on the assumption that:

• A. The rate of mutation is constant across all genes and all species.
• B. Species with more morphological similarities diverged more recently.
• C. Mutations are always beneficial and contribute to increased fitness.
• D. The fossil record provides the most accurate estimates of evolutionary relationships.

Correct answer: A

Rationale: A molecular clock is a method used to estimate the time of divergence between species by measuring the accumulation of mutations in DNA sequences. This method relies on the assumption that mutations occur at a relatively constant rate over time. If the rate of mutation were not constant, it would be challenging to accurately estimate the evolutionary divergence time between species. Therefore, option A is the most appropriate choice as it aligns with the fundamental principle underlying the molecular clock hypothesis. Option B is incorrect because the assumption that species with more morphological similarities diverged more recently does not directly relate to the concept of molecular clocks and the accumulation of mutations in DNA sequences. Option C is incorrect because mutations are not always beneficial and do not always contribute to increased fitness. Mutations can be neutral or deleterious as well, and their accumulation is what is used to estimate evolutionary di

3. Which of the following correctly describes a strong acid?

• A. A strong acid completely ionizes in water.
• B. A strong acid donates more than one proton.
• C. A strong acid contains at least one metal atom.
• D. A strong acid will not decompose.

Correct answer: A

Rationale: The correct answer is A. A strong acid is defined as an acid that completely ionizes in water, meaning it dissociates fully into its constituent ions in solution. This characteristic differentiates strong acids from weak acids, which do not fully dissociate in water. Choice B is incorrect because the number of protons donated does not solely define the strength of an acid. Choice C is incorrect as strong acids are not defined by the presence of metal atoms, and Choice D is incorrect because all acids can decompose, but the strength of the acid is based on its ability to ionize in water.

4. During exercise, oxygen is used to convert glucose into energy for muscles. This process is called:

• A. Aerobic respiration
• B. Anaerobic respiration
• C. Glycolysis
• D. Lactic acid fermentation

Correct answer: A

Rationale: Aerobic respiration is the process by which cells use oxygen to convert glucose into energy. This process occurs in the mitochondria of cells and is the most efficient way to produce energy during exercise. Anaerobic respiration and glycolysis are alternative pathways for energy production when oxygen is limited, typically occurring during high-intensity exercise. Lactic acid fermentation, on the other hand, occurs in the absence of oxygen and leads to the production of lactic acid, causing muscle fatigue and soreness.

5. What is hydroxyapatite?

• A. A mixture of minerals such as calcium and phosphorus that strengthen the collagen matrix of bone.
• B. The structural unit of a bone that runs the length of the bone.
• C. The covering of bones at the point of articulation to prevent grinding.
• D. The lightest portion of a long bone and concentrated at the ends.

Correct answer: A

Rationale: Hydroxyapatite is a mineral compound composed of calcium and phosphorus that plays a crucial role in strengthening the collagen matrix of bones, contributing to their structural integrity and hardness. It is a key component of bone tissue and provides the mineralization necessary for bone strength and density. Choice B is incorrect because the structural unit of a bone is the osteon or Haversian system, not hydroxyapatite. Choice C is incorrect as it describes cartilage, not hydroxyapatite. Choice D is incorrect as it refers to the epiphysis, which is not synonymous with hydroxyapatite.

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