Nursing Elites

1. Decomposers in an ecosystem play a vital role by:

• A. Photosynthesizing and producing organic matter
• B. Breaking down dead organisms and returning nutrients to the environment
• C. Preying on herbivores and controlling their populations
• D. Fixing nitrogen from the atmosphere and making it available to plants

Correct answer: B

Rationale: Rationale: Decomposers are organisms that break down dead organic matter, such as dead plants and animals, into simpler substances. By doing so, they help to recycle nutrients back into the environment, making them available for other organisms to use. This process is essential for the functioning of ecosystems, as it ensures that nutrients are not lost but instead are continuously cycled through the ecosystem. Photosynthesis (option A) is the process by which plants and some other organisms convert light energy into chemical energy in the form of glucose, and it is not a role of decomposers. Preying on herbivores (option C) is a role typically carried out by predators, not decomposers. Fixing nitrogen from the atmosphere (option D) is a process carried out by nitrogen-fixing bacteria, not decomposers.

2. What is the primary hormone released by the parathyroid glands?

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

Correct answer: C

Rationale: The primary hormone released by the parathyroid glands is Parathyroid hormone (PTH), which plays a crucial role in regulating calcium levels in the body. Insulin is produced by the pancreas to regulate blood sugar levels and is unrelated to the parathyroid glands. Calcitonin is produced by the thyroid gland and helps regulate calcium levels but is not the primary hormone released by the parathyroid glands. Thyroxine is a hormone produced by the thyroid gland that regulates metabolism and is also not released by the parathyroid glands. Therefore, the correct answer is C: Parathyroid hormone (PTH).

3. Simplify the expression: -5 + (-8)

• A. -13
• B. 8
• C. 13
• D. -5

Correct answer: A

Rationale: Combine the negative signs by adding them together. -5 + (-8) = -13

4. What type of energy is possessed by an object due to its position or configuration?

• A. Kinetic energy
• B. Thermal energy
• C. Potential energy
• D. Electrical energy

Correct answer: c

Rationale: Potential energy is the energy possessed by an object due to its position or state.

5. Two cars with different masses collide head-on. Which car experiences a greater change in momentum?

• A. The car with the larger mass
• B. The car with the smaller mass
• C. Both cars experience the same change in momentum
• D. It depends on the initial velocities of the cars

Correct answer: B

Rationale: The car with the smaller mass. Although momentum is conserved in the collision, the change in momentum is inversely proportional to mass. Therefore, the car with the smaller mass will experience a larger relative change.

6. What is the relationship between the frequency and wavelength of a wave?

• A. Inversely proportional
• B. Directly proportional
• C. No relationship
• D. Depend on the medium

Correct answer: a

Rationale: Frequency and wavelength have an inverse relationship - as one increases, the other decreases.

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