Nursing Elites

1. According to the theory of evolution by natural selection, which of the following statements is true?

• A. Organisms evolve towards perfection
• B. Traits are acquired through use and disuse
• C. Individuals with favorable traits survive and reproduce more
• D. All of the above

Correct answer: C

Rationale: Rationale: A) Organisms evolve towards perfection - This statement is incorrect. Evolution by natural selection does not suggest that organisms evolve towards perfection. Instead, it emphasizes the adaptation of organisms to their environment over time. B) Traits are acquired through use and disuse - This statement reflects Lamarck's theory of evolution, not Darwin's theory of evolution by natural selection. Lamarck proposed that organisms could acquire traits during their lifetime and pass them on to their offspring, which has been largely discredited. C) Individuals with favorable traits survive and reproduce more - This statement accurately reflects the central concept of Darwin's theory of evolution by natural selection. Individuals with traits that are advantageous in their environment are more likely to survive and reproduce, passing on those traits to future generations. D) All of the above - This option is incorrect because not all of the statements are true. Only option C accurately represents the theory of evolution by natural selection.

2. Which part of the neuron insulates and speeds up the transmission of nerve impulses along the axon?

• A. Dendrite
• B. Myelin sheath
• C. Synapse
• D. Cell body

Correct answer: B

Rationale: The myelin sheath is a fatty layer that surrounds the axon of a neuron, providing insulation and speeding up the transmission of nerve impulses. This insulation helps prevent the loss of electrical signals as they travel along the axon, allowing for faster and more efficient communication within the nervous system. Dendrites are branching extensions of a neuron that receive signals from other neurons, the synapse is the junction between two neurons where communication occurs, and the cell body contains the nucleus and organelles of the neuron, but none of these structures provide insulation for the transmission of nerve impulses along the axon.

3. Which hormone, produced by the thyroid gland, regulates calcium levels in the blood by enhancing calcium absorption in the intestines and reducing calcium loss in the kidneys?

• A. Calcitonin
• B. Parathyroid hormone (PTH)
• C. Thyroxine
• D. Insulin

Correct answer: A

Rationale: Calcitonin is the hormone produced by the thyroid gland that regulates calcium levels in the blood. It enhances calcium absorption in the intestines and reduces calcium loss in the kidneys. Parathyroid hormone (PTH) operates oppositely to calcitonin by increasing calcium levels in the blood. Thyroxine is a thyroid gland hormone that primarily regulates metabolism, not calcium levels. Insulin, produced by the pancreas, is responsible for controlling blood sugar levels, not calcium levels. Therefore, the correct answer is Calcitonin as it specifically targets calcium regulation in the body.

4. Which type of blood cell is responsible for carrying oxygen?

• A. White blood cell
• B. Red blood cell
• C. Platelet
• D. Plasma

Correct answer: B

Rationale: The correct answer is B: Red blood cell. Red blood cells, also known as erythrocytes, are responsible for carrying oxygen from the lungs to the body's tissues. They contain hemoglobin, a protein that binds to oxygen and transports it throughout the body. White blood cells (Choice A) are part of the immune system and help fight infections, not involved in carrying oxygen. Platelets (Choice C) are responsible for blood clotting, not oxygen transport. Plasma (Choice D) is the liquid component of blood that carries various substances like nutrients and waste products, but it does not directly carry oxygen.

5. Which structure in the skin is responsible for producing melanin?

• A. Sudoriferous gland
• B. Melanocyte
• C. Sebaceous gland
• D. Hair follicle

Correct answer: B

Rationale: The correct answer is B: Melanocyte. Melanocytes in the skin are responsible for producing melanin, the pigment that gives skin its color and provides protection against harmful UV radiation. Sudoriferous glands produce sweat, sebaceous glands produce sebum (oil), and hair follicles are associated with hair growth. However, the specific function of producing melanin is attributed to melanocytes, making them the correct answer in this context.

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