Nursing Elites

1. What is the maximum volume of air that the lungs can hold after a full forced inhalation?

• A. Inspiratory capacity
• B. Tidal volume
• C. Total lung capacity
• D. Vital capacity

Correct answer: C

Rationale: Total lung capacity is the correct term for the maximum volume of air that the lungs can hold after a full forced inhalation. It represents the sum of all lung volumes, including tidal volume, inspiratory reserve volume, and expiratory reserve volume. Inspiratory capacity refers to the maximum volume of air inspired from the end-expiratory level. Tidal volume is the volume of air inspired or expired during normal breathing. Vital capacity is the maximum volume of air that can be exhaled after a maximum inhalation, not the total volume the lungs can hold.

2. What is the main function of calcitonin, a hormone produced by the thyroid gland?

• A. Stimulate metabolism and heat production
• B. Increase calcium absorption from the intestines
• C. Enhance bone growth and development
• D. Lower blood calcium levels

Correct answer: D

Rationale: Calcitonin is a hormone produced by the thyroid gland that primarily functions to lower blood calcium levels. It achieves this by inhibiting bone breakdown and promoting calcium excretion by the kidneys. Therefore, the correct answer is D as it reflects the main role of calcitonin in calcium homeostasis. Choices A, B, and C are incorrect as they do not align with the primary function of calcitonin. Calcitonin does not stimulate metabolism and heat production (Choice A), increase calcium absorption from the intestines (Choice B), or enhance bone growth and development (Choice C).

3. Which of the following is NOT a source of genetic variation in a population?

• A. Mutations in genes
• B. Genetic drift (random fluctuations in allele frequencies)
• C. Gene flow (movement of genes between populations)
• D. Blending inheritance (traits of parents are averaged in offspring)

Correct answer: D

Rationale: Rationale: A) Mutations in genes: Mutations are changes in the DNA sequence that can introduce new alleles into a population, leading to genetic variation. B) Genetic drift (random fluctuations in allele frequencies): Genetic drift refers to random changes in allele frequencies in a population, which can lead to genetic variation through chance events. C) Gene flow (movement of genes between populations): Gene flow occurs when individuals move between populations, bringing new alleles with them and increasing genetic variation within populations. D) Blending inheritance (traits of parents are averaged in offspring): Blending inheritance was a historical theory that suggested offspring inherit a blend of traits from their parents, leading to a reduction in genetic variation over time. However, this concept has been disproven by the understanding of Mendelian genetics, where traits are inherited independently and do not blend together. Therefore, blending inheritance does not contribute

4. Which of the following best describes a chemical change?

• A. Melting ice to form water
• B. Dissolving sugar in water
• C. Burning wood to produce ash
• D. Crushing a can to reduce its size

Correct answer: C

Rationale: A chemical change involves a chemical reaction where new substances are formed. Burning wood to produce ash is an example of a chemical change because the wood undergoes a chemical reaction to form a new substance (ash). In this process, the chemical composition of wood changes to produce ash, which is a new substance. On the other hand, melting ice to form water, dissolving sugar in water, and crushing a can to reduce its size are examples of physical changes. In these instances, the substances may change their physical state or appearance but do not undergo a chemical reaction to form new substances. Therefore, choice C is the correct answer as it represents a chemical change, while choices A, B, and D represent physical changes.

5. What is the main function of lysosomes?

• A. Breaking down and recycling cellular waste
• B. Storing carbohydrates
• C. Synthesizing lipids
• D. Transcribing DNA into mRNA

Correct answer: A

Rationale: The main function of lysosomes is to break down and recycle cellular waste materials, such as old organelles, foreign substances, and cellular debris. This process is crucial for maintaining cellular homeostasis and proper functioning. Storing carbohydrates (B), synthesizing lipids (C), and transcribing DNA into mRNA (D) are not functions typically associated with lysosomes. Storing carbohydrates is primarily done by other organelles like vacuoles. Synthesizing lipids is a function usually associated with the endoplasmic reticulum and transcribing DNA into mRNA occurs in the nucleus by the process of transcription.

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