Nursing Elites

1. What is the primary function of the myelin sheath that surrounds some axons in the nervous system?

• A. To initiate nerve impulses
• B. To transmit sensory information
• C. To speed up the transmission of nerve impulses
• D. To connect neurons at synapses

Correct answer: c

Rationale: The primary function of the myelin sheath that surrounds some axons in the nervous system is to speed up the transmission of nerve impulses. The myelin sheath acts as an insulating layer, which helps nerve impulses travel faster along the axon by allowing them to 'jump' from one node of Ranvier to the next, a process known as saltatory conduction. This increases the efficiency and speed of signal transmission, enabling rapid communication within the nervous system. Therefore, option C is the correct answer as it accurately describes the role of the myelin sheath in enhancing the speed of nerve impulse transmission.

2. The largest level of ecological organization is a:

• A. Population
• B. Community
• C. Ecosystem
• D. Biome

Correct answer: D

Rationale: Rationale: A) Population: A population consists of individuals of the same species living in the same area. It is a smaller level of ecological organization compared to a biome. B) Community: A community consists of populations of different species living and interacting in the same area. It is a larger level of organization than a population but smaller than an ecosystem or biome. C) Ecosystem: An ecosystem includes all living organisms (biotic factors) and their physical environment (abiotic factors) interacting in a particular area. It is a larger level of organization than a community but smaller than a biome. D) Biome: A biome is the largest level of ecological organization and encompasses a large geographic area characterized by a specific climate, vegetation, and animal life. Biomes can be found on multiple continents and are defined by similar abiotic and biotic factors.

3. Insulin, a hormone responsible for regulating blood sugar levels, is produced by the:

• A. Parathyroid gland
• B. Pancreas
• C. Thymus gland
• D. Ovaries

Correct answer: B

Rationale: The correct answer is B: Pancreas. Insulin is a hormone that plays a crucial role in regulating blood sugar levels by allowing cells to take in glucose from the bloodstream. The pancreas is an organ located near the stomach that contains clusters of cells called islets of Langerhans, which are responsible for producing insulin. The parathyroid gland, option A, regulates calcium levels in the blood. The thymus gland, option C, is involved in the development of the immune system. The ovaries, option D, produce hormones like estrogen and progesterone but not insulin. Therefore, the pancreas is the correct gland responsible for producing insulin.

4. What is the Doppler effect, and how does it explain the shift in frequency of sound waves perceived by an observer?

• A. It only affects light waves, not sound waves.
• B. It's the change in wave speed due to medium density.
• C. It's the perceived change in frequency due to relative motion.
• D. It's the bending of waves due to different mediums.

Correct answer: C

Rationale: The Doppler effect describes how the perceived frequency of a wave changes depending on the relative motion between the source and observer. For example, an approaching siren sounds higher pitched due to compressed wavefronts, while a receding siren sounds lower due to stretched wavefronts.

5. How is power related to time?

• A. Power is inversely proportional to time
• B. Power is directly proportional to time
• C. Power is unrelated to time
• D. Power is the product of time and work

Correct answer: c

Rationale: Power is the rate at which work is done or energy is transferred, and it is not directly linked to time.

6. What is the protective sac surrounding the testes in the male reproductive system?

• A. Vas deferens
• B. Scrotum
• C. Epididymis
• D. Urethra

Correct answer: B

Rationale: The correct answer is B: Scrotum. The scrotum is the protective sac surrounding the testes in the male reproductive system. It houses and protects the testes, helping to regulate their temperature for optimal sperm production. The vas deferens is a duct that carries sperm from the testes to the urethra. The epididymis is a coiled tube where sperm mature and are stored. The urethra is a tube that carries urine from the bladder and semen from the reproductive system. Therefore, the scrotum is the specific structure that directly surrounds and protects the testes in the male reproductive system.

Similar Questions