Nursing Elites

1. The mixture of gases surrounding a planet is referred to as its ______.

• A. Atmosphere
• B. Stratosphere
• C. Biosphere
• D. Troposphere

Correct answer: A

Rationale: The mixture of gases surrounding a planet is referred to as its atmosphere. The atmosphere plays a crucial role in supporting life on Earth by providing oxygen, regulating carbon dioxide levels, and shielding the planet from harmful radiation. While the stratosphere, troposphere, and other layers are part of the atmosphere, the term 'atmosphere' encompasses the entire gaseous envelope surrounding a planet. The stratosphere, troposphere, mesosphere, thermosphere, and exosphere are specific layers within the atmosphere, each with distinct characteristics and functions.

2. Which type of passive transport uses proteins that change shape to move a target molecule through the membrane?

• A. Diffusion
• B. Carrier proteins
• C. Channel proteins
• D. None of the above

Correct answer: B

Rationale: The correct answer is B: Carrier proteins. Carrier proteins are involved in facilitated diffusion, a type of passive transport where specific target molecules are moved across the membrane with the help of proteins that change shape. These carrier proteins bind to the target molecule on one side of the membrane, undergo a conformational change, and then release the molecule on the other side. This process is crucial for the selective transport of certain molecules that cannot pass through the membrane by simple diffusion. Choices A and C are incorrect because diffusion and channel proteins do not involve proteins that change shape to transport target molecules selectively. Choice D is incorrect as carrier proteins fit the description provided in the question.

3. Which of the following bases is not present in RNA?

• A. Adenine
• B. Thymine
• C. Uracil
• D. Cytosine

Correct answer: B

Rationale: Thymine is not present in RNA. RNA uses uracil as one of its bases, which pairs with adenine. In RNA, adenine does not pair with thymine as in DNA. Cytosine and guanine are the other two bases found in both RNA and DNA.

4. Which of the following is not a function of the skeletal system?

• A. Providing the shape and form of our bodies
• B. Supporting and protecting the body
• C. Producing blood
• D. Storing vitamins

Correct answer: C

Rationale: Producing blood is not a function of the skeletal system. Blood production primarily occurs in the bone marrow, which is found within the bones. The skeletal system provides the shape and form of our bodies, supports and protects the body, and stores minerals like calcium and phosphorus for various functions. Storing vitamins is not a primary function of the skeletal system, although some vitamins may play a role in bone health.

5. How should a researcher test the hypothesis that eating chocolate leads to acne in teenagers?

• A. Take 100 teenagers and feed each one a different amount of chocolate daily for 60 days; then test for acne.
• B. Take 100 teenagers and feed 50 two bars of chocolate daily for 60 days while the other 50 eat no chocolate; then test for acne.
• C. Take 1 teenager and feed him or her two bars of chocolate for 30 days and no chocolate for 30 days; then test for acne.
• D. Take 100 teenagers and feed them no chocolate for 30 days and two bars of chocolate apiece for 30 days; then test for acne.

Correct answer: B

Rationale: Option B is the correct approach to test the hypothesis that eating chocolate leads to acne in teenagers. This method involves having a control group (50 teenagers not consuming chocolate) and an experimental group (50 teenagers consuming two bars of chocolate daily), which allows for comparison. By having two distinct groups, researchers can assess the impact of chocolate consumption on acne development. Option A lacks a control group for comparison, making it harder to attribute any observed effects specifically to chocolate consumption. Option C only involves a single subject, which limits the generalizability of the results. Option D, where all teenagers experience both conditions, does not allow for a direct comparison between chocolate consumption and acne development, as all subjects are exposed to both conditions.

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