Nursing Elites

1. What is the primary function of the heart?

• A. Filtering blood
• B. Exchanging gases
• C. Pumping blood throughout the body
• D. Producing hormones

Correct answer: C

Rationale: The main function of the heart is to pump blood throughout the body. The heart acts as a muscular pump that circulates blood, delivering oxygen and nutrients to the body's tissues and removing waste products. Option A is incorrect because blood filtration is a function of the kidneys, not the heart. Option B is incorrect as gas exchange occurs in the lungs, not the heart. Option D is also incorrect as hormone production is mainly carried out by endocrine glands, not the heart.

2. Which hormone, produced by the pituitary gland, stimulates the production of milk in mammary glands during breastfeeding?

• A. Growth hormone (GH)
• B. Thyroid-stimulating hormone (TSH)
• C. Prolactin
• D. Follicle-stimulating hormone (FSH)

Correct answer: C

Rationale: Prolactin is the hormone produced by the pituitary gland that stimulates the production of milk in mammary glands during breastfeeding. It plays a crucial role in lactation by promoting the development of mammary tissue and the production of milk. Growth hormone (GH), thyroid-stimulating hormone (TSH), and follicle-stimulating hormone (FSH) do not directly stimulate milk production in mammary glands. Therefore, choices A, B, and D are incorrect in the context of stimulating milk production during breastfeeding.

3. Which of the following is an example of a nonpolar solvent?

• A. Water
• B. Ethanol
• C. Acetone
• D. Hydrochloric acid

Correct answer: B

Rationale: - Water (option A) is a polar solvent due to its uneven distribution of charge, with the oxygen atom being partially negative and the hydrogen atoms being partially positive. - Ethanol (option B) is a nonpolar solvent because it has a symmetrical molecular structure that does not result in significant charge separation. - Acetone (option C) is a polar solvent as it contains a carbonyl group that results in a partial negative charge on the oxygen atom. - Hydrochloric acid (option D) is a polar solvent due to the presence of the highly electronegative chlorine atom, which results in a partial negative charge.

4. What are the three main types of RNA?

• A. Messenger RNA (mRNA), ribosomal RNA (rRNA), and transfer RNA (tRNA)
• B. DNA, RNA, and protein
• C. Adenine, guanine, cytosine, and thymine
• D. Deoxyribose, ribose, and phosphate

Correct answer: A

Rationale: - Messenger RNA (mRNA) carries genetic information from the DNA in the nucleus to the ribosomes in the cytoplasm for protein synthesis. - Ribosomal RNA (rRNA) is a structural component of ribosomes, which are the cellular machinery responsible for protein synthesis. - Transfer RNA (tRNA) is responsible for bringing amino acids to the ribosome during protein synthesis. Options B, C, and D are incorrect: - Option B lists DNA, RNA, and protein, which are biomolecules but not the three main types of RNA. - Option C lists nitrogenous bases (adenine, guanine, cytosine, and thymine) found in DNA, not types of RNA. - Option D lists components of nucleotides (deoxyribose, ribose, and phosphate), which are building blocks of nucleic

5. How can a single gene mutation lead to multiple phenotypes depending on the organism?

• A. Pleiotropy describes the effect of one gene influencing multiple seemingly unrelated traits.
• B. Epigenetics involves environmental factors modifying gene expression without altering the DNA sequence.
• C. Genetic drift refers to random changes in allele frequencies within a population.
• D. Gene regulation controls the timing and level of gene expression within an organism.

Correct answer: A

Rationale: A single gene mutation can lead to multiple phenotypes through pleiotropy, where one gene influences diverse traits or functions in an organism. This phenomenon occurs when the mutated gene affects different biochemical pathways, developmental processes, or cellular functions, resulting in a cascade of downstream effects that manifest as a variety of phenotypic outcomes. Choice B, epigenetics, involves modifications in gene expression influenced by environmental factors without altering the DNA sequence, which is not directly related to the question about single gene mutations causing multiple phenotypes. Choice C, genetic drift, refers to random changes in allele frequencies within a population, which is unrelated to the impact of a single gene mutation on multiple phenotypes. Choice D, gene regulation, focuses on controlling the timing and level of gene expression within an organism, which is not directly addressing how a single gene mutation can lead to diverse phenotypes.

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