Nursing Elites

1. Myelin sheath is a fatty substance that insulates and protects the long extensions of some nerve cells. It is produced by:

• A. Schwann cells
• B. Astrocytes
• C. Neurons
• D. Oligodendrocytes

Correct answer: A

Rationale: Schwann cells are indeed responsible for producing the myelin sheath in the peripheral nervous system. These cells wrap around axons to form the myelin sheath, which enhances the speed of nerve impulse conduction. In the central nervous system, oligodendrocytes are responsible for producing the myelin sheath. Astrocytes provide support and maintenance functions for neurons, while neurons are the nerve cells themselves and do not produce myelin. Therefore, the correct answer is Schwann cells as they are specifically involved in myelin production in the peripheral nervous system.

2. What is a characteristic feature of a convex lens?

• A. Converge light rays
• B. Diverge light rays
• C. Focus sound waves
• D. Create virtual images only

Correct answer: A

Rationale: A convex lens is characterized by its ability to converge light rays. The convex lens is thicker in the middle and thinner at the edges, causing light rays passing through it to converge or come together at a focal point on the opposite side of the lens. This convergence of light rays is what distinguishes convex lenses. Choice B is incorrect as convex lenses do not diverge light rays. Choice C is incorrect as convex lenses do not focus sound waves but rather light waves. Choice D is incorrect as convex lenses can create both real and virtual images, not just virtual images.

3. What is a submicroscopic entity that is considered nonliving because it lacks cellular structure and consists of nucleic acids encapsulated in a protein coat called a capsid?

• A. Bacteria
• B. Fungus
• C. Virus
• D. Protozoa

Correct answer: C

Rationale: The correct answer is C: Virus. Viruses are not considered living organisms because they lack cellular structure. Instead, they are composed of nucleic acids (either DNA or RNA) enclosed in a protein coat called a capsid. Bacteria (choice A), fungus (choice B), and protozoa (choice D) are all living organisms with cellular structures, unlike viruses. Therefore, they are incorrect choices for this question.

4. What function do genes serve in the relationship between parents and offspring?

• A. Genes enable hereditary information to be passed from parents to offspring.
• B. Genes prohibit hereditary information from being passed from parents to offspring.
• C. Genes enable environmental factors to affect parents and offspring.
• D. Genes serve no function in the relationship between parents and offspring.

Correct answer: A

Rationale: Genes play a crucial role in passing hereditary information from parents to offspring, ensuring the transmission of genetic traits. This process forms the basis of inheritance and genetic continuity between generations. Choice B is incorrect as genes do not prohibit but rather facilitate the transmission of hereditary information. Choice C is incorrect because genes primarily transmit genetic information, while the influence of environmental factors is separate. Choice D is incorrect as genes are fundamental in genetic inheritance and the relationship between parents and offspring.

5. Which of the following is responsible for regulating body temperature?

• A. Hypothalamus
• B. Cerebellum
• C. Pituitary gland
• D. Thyroid gland

Correct answer: A

Rationale: The correct answer is the Hypothalamus. The hypothalamus plays a crucial role in regulating body temperature, hunger, thirst, and maintaining overall homeostasis in the body. It receives input from temperature receptors in the skin and internal organs and helps initiate responses to maintain a stable internal body temperature. Acting as the body's thermostat, the hypothalamus adjusts responses to ensure the body's temperature remains within a narrow range, despite external conditions. The Cerebellum (Choice B) is primarily involved in coordinating movement and balance, not regulating body temperature. The Pituitary gland (Choice C) is responsible for producing and secreting hormones that regulate various bodily functions but not directly involved in body temperature regulation. The Thyroid gland (Choice D) plays a role in metabolism and hormone regulation but is not the primary regulator of body temperature.

Similar Questions