Nursing Elites

1. Which of the following terms refers to a muscle that lengthens while another muscle contracts to produce movement?

• A. Synergist
• B. Agonist
• C. Antagonist
• D. Flexor

Correct answer: C

Rationale: The correct answer is C: Antagonist. In muscle physiology, an antagonist refers to a muscle that lengthens while another muscle contracts to produce movement. This relationship allows for smooth and coordinated movement by controlling the action of the agonist muscle. For example, when you bend your arm, the biceps muscle (agonist) contracts to flex the arm while the triceps muscle (antagonist) lengthens to allow for this movement. Synergists assist the agonist muscle in performing a movement, while flexors are a type of muscle that decreases the angle between bones at a joint. Therefore, the antagonist best fits the description of a muscle that lengthens while another muscle contracts.

2. You observe that plants in a greenhouse grow faster when exposed to red light compared to blue light. What is the next best step in your investigation?

• A. Increase the intensity of the blue light.
• B. Decrease the intensity of the red light.
• C. Grow plants in complete darkness.
• D. Grow plants exposed to both red and blue light at equal intensities.

Correct answer: D

Rationale: The next best step in the investigation would be to grow plants exposed to both red and blue light at equal intensities. This will help determine if the observed growth difference is due to the specific wavelength of light (red vs. blue) or if it is related to the intensity of light. By exposing plants to both red and blue light at equal intensities, you can compare their growth rates and determine if one wavelength has a greater effect on plant growth.

3. The element responsible for the green color of leaves is:

• A. Magnesium
• B. Iron
• C. Copper
• D. Zinc

Correct answer: A

Rationale: Magnesium is the central element of chlorophyll, the pigment responsible for photosynthesis

4. Positive integers are greater than zero. Which of the following expressions results in the largest positive number?

• A. (2 + 3)^2
• B. 5 x 7 + 2
• C. 10^2 - 4^2
• D. (8 - 1) x 3

Correct answer: C

Rationale: 10^2 - 4^2 = 100 - 16 = 84

5. Which muscle type is characterized by a combination of voluntary and involuntary control, is striated, and is responsible for pumping blood throughout the circulatory system?

• A. Skeletal muscle
• B. Smooth muscle
• C. Cardiac muscle
• D. Connective tissue

Correct answer: c

Rationale: The correct answer is C: Cardiac muscle. Cardiac muscle is characterized by a combination of voluntary and involuntary control, as the heart can beat involuntarily while also responding to signals from the autonomic nervous system. It is striated, meaning it has a striped appearance under a microscope due to the arrangement of contractile proteins. Cardiac muscle is responsible for pumping blood throughout the circulatory system, making it crucial for maintaining circulation and delivering oxygen and nutrients to tissues. Skeletal muscle (option A) is primarily under voluntary control and is responsible for movement, while smooth muscle (option B) is predominantly involuntarily controlled and found in organs like the intestines. Connective tissue (option D) provides support and structure but is not a muscle type responsible for pumping blood.

6. What is the main difference between a nuclear reactor and a nuclear bomb?

• A. Reactors use enriched uranium, while bombs use natural uranium.
• B. Reactors have controlled chain reactions, while bombs have uncontrolled chain reactions.
• C. Reactors generate electricity, while bombs cause explosions.
• D. Reactors use moderators, while bombs don't.

Correct answer: B

Rationale: The key difference lies in the control of the fission chain reaction. Reactors have controlled reactions for energy generation, while bombs have rapid, uncontrolled reactions creating explosions.

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