Nursing Elites

1. Which neuromuscular system controls voluntary movement?

• A. Autonomic
• B. Somatic
• C. Sympathetic
• D. Parasympathetic

Correct answer: B

Rationale: The correct answer is B, Somatic. The somatic nervous system controls voluntary movements of skeletal muscles. It is responsible for carrying sensory and motor information to and from the central nervous system. Choices A, C, and D are incorrect. The autonomic nervous system (choice A) controls involuntary functions such as heart rate and digestion. The sympathetic (choice C) and parasympathetic (choice D) nervous systems are subdivisions of the autonomic nervous system and are responsible for the body's fight-or-flight response and rest-and-digest functions, respectively.

2. Osteoporosis is a condition that leads to weakened bones and an increased risk of fractures. Which hormone plays a key role in bone health and is often affected in osteoporosis?

• A. Estrogen
• B. Testosterone
• C. Thyroid hormone
• D. Insulin

Correct answer: A

Rationale: Estrogen plays a crucial role in maintaining bone health by inhibiting bone resorption and promoting bone formation. In postmenopausal women, estrogen levels decrease, leading to an increased risk of osteoporosis due to accelerated bone loss. This hormonal imbalance contributes to weakened bones and an increased risk of fractures in individuals with osteoporosis. Testosterone and thyroid hormone do play roles in bone health, but estrogen has a more significant impact. Testosterone is more commonly associated with muscle mass and strength, while thyroid hormone regulates metabolism. Insulin is not directly involved in bone health and is not typically affected in osteoporosis.

3. Which of the following characteristics is part of a person's genotype?

• A. Brown eyes that appear hazel in the sunlight
• B. The CFTR gene, which causes cystic fibrosis
• C. Black hair that grows rapidly
• D. Being a fast runner

Correct answer: B

Rationale: The correct answer is B. A genotype refers to a person's genetic makeup, which includes specific genes like the CFTR gene responsible for cystic fibrosis. Genes are the units of heredity and are part of an individual's genotype, influencing various traits and characteristics. Choice A, brown eyes that appear hazel in the sunlight, refers to a phenotype, which is the observable characteristics resulting from the interaction of genes and the environment. Choice C, black hair that grows rapidly, also describes a phenotype rather than a genotype. Choice D, being a fast runner, is a trait influenced by a combination of genetic and environmental factors, but it does not directly relate to a specific gene in the genotype.

4. Scientists compare the DNA of different organisms to understand evolutionary relationships. What is this type of evidence called?

• A. Morphological evidence (comparing body structures)
• B. Biochemical evidence (comparing molecules like proteins)
• C. Geographic distribution evidence (where organisms live)
• D. Genetic evidence (comparing DNA sequences)

Correct answer: D

Rationale: A) Morphological evidence involves comparing body structures of organisms, which can provide information about evolutionary relationships based on physical similarities and differences. However, DNA comparison is a more direct and accurate method for understanding evolutionary relationships. B) Biochemical evidence involves comparing molecules like proteins, which can also provide insights into evolutionary relationships. However, DNA comparison is considered more reliable due to the direct relationship between DNA sequences and genetic information. C) Geographic distribution evidence refers to where organisms live and how their distribution may provide clues about evolutionary history. While this can be informative, it is not as direct or specific as comparing DNA sequences. D) Genetic evidence involves comparing DNA sequences of different organisms to understand their evolutionary relationships. DNA comparison is a powerful tool in evolutionary biology because it provides direct information about genetic similarities and differences, offering precise insights into evolutionary relationships.

5. When ethanol (C₂H₅OH) reacts with sodium metal (Na), what is the product?

• A. Ethene (C₂H₄)
• B. Sodium ethoxide (C₂H₅ONa)
• C. Ethane (C₂H₆)
• D. Sodium acetate (CH₃COONa)

Correct answer: B

Rationale: When ethanol (C₂H₅OH) reacts with sodium metal (Na), the product formed is Sodium ethoxide (C₂H₅ONa). This reaction is a classic example of a metal displacing hydrogen in an alcohol to form an alkoxide. In this specific case, sodium replaces the hydrogen in ethanol, resulting in the formation of sodium ethoxide. Choice A, Ethene (C₂H₄), is incorrect as it is a different compound formed from the dehydration of ethanol, not its reaction with sodium. Choice C, Ethane (C₂H₆), is incorrect as it is a saturated hydrocarbon, not the product of the reaction of ethanol with sodium metal. Choice D, Sodium acetate (CH₃COONa), is incorrect as it involves acetic acid, not ethanol, reacting with sodium to form the salt sodium acetate.

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