Nursing Elites

1. The neutral theory of molecular evolution proposes that:

• A. Most mutations in DNA are selectively neutral and do not affect an organism's fitness.
• B. All mutations are beneficial and contribute to the adaptation of a population.
• C. The rate of evolution is primarily driven by strong directional selection pressures.
• D. Genetic drift plays a negligible role in shaping genetic variation within populations.

Correct answer: A

Rationale: Rationale: A) The neutral theory of molecular evolution, proposed by Motoo Kimura in the 1960s, suggests that the majority of mutations that occur in DNA are selectively neutral, meaning they do not have a significant impact on an organism's fitness. These neutral mutations are not subject to natural selection and are allowed to accumulate in populations over time. This theory helps explain the high levels of genetic variation observed within populations. B) Option B is incorrect because not all mutations are beneficial. Mutations can be neutral, harmful, or beneficial, and the neutral theory specifically focuses on the idea that many mutations are neutral in their effects. C) Option C is incorrect because the neutral theory suggests that evolution is not primarily driven by strong directional selection pressures. Instead, it emphasizes the role of genetic drift and the accumulation of neutral mutations in shaping genetic variation. D) Option D is incorrect because

2. What is the role of platelets in the blood?

• A. Transport oxygen
• B. Fight infection
• C. Produce antibodies
• D. Clot blood

Correct answer: D

Rationale: Platelets play a crucial role in blood clotting by forming clots to help stop bleeding. While red blood cells transport oxygen, white blood cells fight infection, and immune cells produce antibodies, platelets specifically function to prevent excessive bleeding by forming clots. Therefore, the correct answer is D. Choices A, B, and C are incorrect as they describe functions of other components of the blood, not platelets.

3. What is the ultimate end product of glucose breakdown in glycolysis?

• A. ATP
• B. NADPH
• C. Pyruvic acid
• D. Oxygen

Correct answer: C

Rationale: The ultimate end product of glucose breakdown in glycolysis is pyruvic acid. During glycolysis, glucose is broken down into pyruvic acid through a series of enzymatic reactions. ATP is produced as an energy carrier during glycolysis, but it is not the final end product. NADPH is not a direct product of glycolysis; it is mainly produced in the pentose phosphate pathway. Oxygen is not a product of glycolysis but is used as an electron acceptor in the electron transport chain of cellular respiration.

4. What is the neural pathway that triggers a reflex action?

• A. Reflex loop
• B. Reflex arc
• C. Neural pathway
• D. Reflex reaction

Correct answer: B

Rationale: The correct answer is 'B: Reflex arc.' A reflex arc is the neural pathway that triggers an automatic, involuntary reflex action in response to a stimulus. It involves sensory neurons, interneurons in the spinal cord, and motor neurons, allowing for a rapid response without conscious thought. Choice A, 'Reflex loop,' is incorrect as the term commonly used is 'Reflex arc' to describe this neural pathway. Choice C, 'Neural pathway,' is too general and does not specifically refer to the pathway involved in reflex actions. Choice D, 'Reflex reaction,' is not the commonly accepted term to describe the neural pathway that triggers reflex actions.

5. Which three parts make up the large intestine?

• A. Duodenum, ileum, jejunum
• B. Cecum, colon, rectum
• C. Ileum, jejunum, rectum
• D. Colon, cecum, ileum

Correct answer: B

Rationale: The correct answer is B: Cecum, colon, rectum. The large intestine is composed of the cecum, colon, and rectum. These parts are responsible for water absorption and feces formation. Choices A, C, and D are incorrect. A contains parts of the small intestine (duodenum, ileum, jejunum), C has a mix of small and large intestine parts, and D includes the small intestine part ileum. Understanding the correct anatomy of the large intestine is essential for distinguishing it from the small intestine.

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