Nursing Elites

1. Why is biodiversity important for healthy ecosystems?

• A. Increases stability and resilience to disturbances
• B. Provides stability and resilience to disturbances
• C. Slows down nutrient cycling
• D. Reduces the number of decomposers

Correct answer: B

Rationale: Biodiversity refers to the variety of living organisms in a particular area. A diverse ecosystem is better able to withstand and recover from disturbances such as natural disasters, climate change, or human impacts. This is because different species play unique roles in the ecosystem, and a higher level of biodiversity means there are more species available to fulfill these roles. For example, if one species is negatively affected by a disturbance, other species may be able to compensate for its loss, maintaining the overall functioning of the ecosystem. Therefore, biodiversity provides stability and resilience to disturbances, making ecosystems healthier and more sustainable. Choice A is incorrect because biodiversity doesn't increase competition for resources but rather helps in maintaining a balance within the ecosystem. Choice C is incorrect as biodiversity does not slow down nutrient cycling; in fact, it enhances nutrient cycling by ensuring a variety of species involved in the process. Choice D is incorrect as biodiversity does not reduce the number of decomposers but instead supports a diverse community of decomposers that are essential for nutrient recycling in ecosystems.

2. Which organelle is responsible for cellular respiration, producing ATP for energy?

• A. Nucleus
• B. Mitochondria
• C. Golgi apparatus
• D. Vacuole

Correct answer: B

Rationale: The correct answer is B) Mitochondria. Mitochondria are known as the powerhouse of the cell because they are responsible for cellular respiration, a process that produces ATP (adenosine triphosphate) for energy. The other organelles listed, such as the nucleus, Golgi apparatus, and vacuole, have distinct functions within the cell and are not directly involved in cellular respiration. The nucleus contains genetic material, the Golgi apparatus is involved in protein processing and packaging, and the vacuole is responsible for storage and maintaining cell turgor pressure.

3. The adrenal cortex produces a group of steroid hormones called corticosteroids. What is a MAJOR function of corticosteroids?

• A. Regulate insulin sensitivity and blood sugar levels
• B. Control blood pressure and electrolyte balance
• C. Stimulate the immune system and inflammatory response
• D. Promote growth and development during puberty

Correct answer: B

Rationale: Corticosteroids, produced by the adrenal cortex, primarily function to control blood pressure and electrolyte balance. One of the key corticosteroids, aldosterone, plays a crucial role in regulating sodium and potassium levels in the body. This regulation is essential for maintaining blood pressure and electrolyte balance. Choices A, C, and D are incorrect because corticosteroids do not primarily regulate insulin sensitivity and blood sugar levels, stimulate the immune system and inflammatory response, or promote growth and development during puberty. While corticosteroids can have effects on insulin sensitivity, immune response, and growth, their major role is in maintaining blood pressure and electrolyte balance.

4. Which of the following glands is responsible for regulating metabolism?

• A. Thymus
• B. Pituitary
• C. Pancreas
• D. Thyroid

Correct answer: D

Rationale: The correct answer is D, Thyroid. The thyroid gland is responsible for regulating metabolism by producing thyroid hormones. These hormones play a crucial role in controlling various metabolic processes in the body, including energy production and utilization. Choice A, Thymus, is not responsible for regulating metabolism but plays a role in the immune system. Choice B, Pituitary, regulates various hormones but not specifically focused on metabolism. Choice C, Pancreas, is involved in insulin production and blood sugar regulation but is not primarily responsible for regulating metabolism.

5. Salts are formed by the reaction between:

• A. Two acids
• B. An acid and a base
• C. Two bases
• D. A metal and a nonmetal only

Correct answer: B

Rationale: Salts are formed by the reaction between an acid and a base. This reaction is known as a neutralization reaction. In this reaction, the acid donates a proton (H+) to the base, resulting in the formation of water and a salt as the products. Choice A is incorrect because salts are not formed by the reaction of two acids. Choice C is incorrect as salts are not produced by the reaction of two bases. Choice D is incorrect because while salts can be formed from the reaction between a metal and a nonmetal, it is not the only way salts are produced.

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