Nursing Elites

1. Which of the following statements regarding macrophages is incorrect?

• A. They are found abundantly in the blood
• B. They are larger than neutrophils
• C. They are long-lived
• D. They are made in the bone marrow as monocytes, called macrophages once they reach organs

Correct answer: A

Rationale: The correct answer is A. Macrophages are not found abundantly in the blood; they are present in tissues and organs. Macrophages are tissue-resident immune cells that play a key role in immune responses and are derived from monocytes produced in the bone marrow. Choice B is correct as macrophages are larger than neutrophils. Choice C is correct as macrophages are long-lived cells. Choice D is correct as macrophages originate in the bone marrow as monocytes and differentiate into macrophages once they migrate to various tissues and organs.

2. Which part of the brain is responsible for coordinating muscle movements, maintaining balance, and posture?

• A. Cerebrum
• B. Cerebellum
• C. Medulla oblongata
• D. Thalamus

Correct answer: B

Rationale: The correct answer is B, the cerebellum. The cerebellum plays a crucial role in coordinating muscle movements, maintaining balance, and posture. It receives inputs from sensory systems, the spinal cord, and other brain regions to fine-tune motor movements. The cerebrum, choice A, is primarily involved in higher brain functions like thinking and decision-making. The medulla oblongata, choice C, controls essential functions such as breathing and heart rate. The thalamus, choice D, serves as a relay center for sensory information but is not directly responsible for coordinating muscle movements, balance, or posture.

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. What is the main function of the lungs?

• A. To transport oxygen and nutrients throughout the body
• B. To coordinate movement and sensory information
• C. To filter waste products from the blood
• D. To exchange oxygen and carbon dioxide between the body and the environment

Correct answer: D

Rationale: The main function of the lungs is to exchange oxygen and carbon dioxide between the body and the environment. This process occurs through the alveoli in the lungs where oxygen from inhaled air enters the bloodstream, and carbon dioxide is removed from the bloodstream and exhaled. Option A is incorrect as the transportation of oxygen and nutrients throughout the body is primarily carried out by the circulatory system, not the lungs. Option B is incorrect as coordinating movement and sensory information is a function of the nervous system, not the lungs. Option C is incorrect as filtering waste products from the blood is primarily the role of the kidneys, not the lungs. Therefore, the correct answer is D.

5. Which of Mendel's Laws states that alleles for a gene segregate during gamete formation?

• A. Law of Independent Assortment
• B. Law of Segregation
• C. Law of Dominance
• D. Law of Probability

Correct answer: B

Rationale: The Law of Segregation, proposed by Gregor Mendel, states that alleles for a gene segregate during gamete formation. This means that each parent passes on only one allele for each gene to their offspring. This law explains how genetic diversity is maintained and how different combinations of alleles are generated in offspring. The Law of Independent Assortment (option A) is not the correct answer as it states that alleles of different genes assort independently of each other during gamete formation, not specifically alleles of a single gene. The Law of Dominance (option C) is incorrect as it pertains to the expression of alleles rather than their segregation during gamete formation. The Law of Probability (option D) is also incorrect as it is a general concept describing the likelihood of events, not specifically related to alleles segregating during gamete formation.

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