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. Which molecule is responsible for storing and providing a quick source of energy during short bursts of intense physical activity, such as weightlifting or sprinting?

• A. ATP (Adenosine Triphosphate)
• B. Glucose
• C. Myoglobin
• D. Lactic Acid

Correct answer: a

Rationale: The correct answer is A: ATP (Adenosine Triphosphate). ATP is known as the energy currency of the cell and is responsible for storing and providing quick energy during short bursts of intense physical activity. When muscles require immediate energy for activities like weightlifting or sprinting, ATP is broken down to release energy rapidly. Glucose is a source of energy but needs to be converted into ATP before it can be used by the muscles. Myoglobin is a protein that stores oxygen in muscle cells, not energy. Lactic Acid is produced during intense exercise but is not a direct source of quick energy like ATP.

3. 7 is divisible by which of the following numbers?

• A. 2 only
• B. 3 only
• C. 1 and 7 only
• D. 2, 3, and 7

Correct answer: D

Rationale: Rationale: 1. 7 is divisible by 1 because every number is divisible by 1. 2. 7 is divisible by 7 because any number is divisible by itself. 3. 7 is not divisible by 2 because 7 is an odd number and not divisible by 2. 4. 7 is not divisible by 3 because the sum of the digits of 7 (7) is not divisible by 3. Therefore, 7 is divisible by 1, 7, and itself (7), making the correct answer D) 2, 3, and 7.

4. The human eye focuses light by adjusting the shape of its:

• A. Cornea
• B. Iris
• C. Lens
• D. Retina

Correct answer: C

Rationale: The human eye focuses light by adjusting the shape of its lens. The cornea is the transparent outer covering of the eye that helps to focus light, but it does not change shape. The iris regulates the amount of light entering the eye through the pupil but does not adjust the shape of the light. The retina is the layer at the back of the eye that receives and processes light signals but does not play a role in focusing light. Therefore, the correct answer is C, the lens, as it changes shape to focus light onto the retina, allowing for clear vision.

5. Which property of a substance refers to its ability to be stretched into thin wires without breaking?

• A. Conductivity
• B. Viscosity
• C. Ductility
• D. Malleability

Correct answer: c

Rationale: Ductility is the property that describes a substance's ability to be stretched into thin wires without breaking.

6. Which of the following is responsible for generating the electrical impulses that regulate the heartbeat?

• A. Aorta
• B. Pulmonary veins
• C. Coronary arteries
• D. Sinoatrial (SA) node

Correct answer: D

Rationale: The correct answer is D: Sinoatrial (SA) node. The SA node, also known as the heart's natural pacemaker, is responsible for generating the electrical impulses that regulate the heartbeat. These impulses initiate each heartbeat by causing the atria to contract. The other options, Aorta, Pulmonary veins, and Coronary arteries, are important structures in the cardiovascular system but are not directly responsible for generating the electrical impulses that regulate the heartbeat.

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