Nursing Elites

1. The dark, round structures observed within some bacterial cells are most likely:

• A. Ribosomes
• B. Flagella
• C. Endospores
• D. Capsules

Correct answer: C

Rationale: Endospores are the correct answer. Endospores are dark, round structures observed within some bacterial cells. They are highly resistant dormant structures formed by certain bacteria in response to harsh environmental conditions. Ribosomes are not dark, round structures within bacterial cells; they are responsible for protein synthesis. Flagella are long, whip-like appendages used for movement and are not dark, round structures within bacterial cells. Capsules are outer layers of polysaccharides that some bacteria produce for protection and adherence, not dark, round structures within bacterial cells.

2. What is the term for a substance that can act as both a proton donor and a proton acceptor?

• A. Acid
• B. Base
• C. Amphiprotic
• D. Neutral

Correct answer: C

Rationale: Amphiprotic substances are those that can both donate and accept protons. They possess characteristics of both acids and bases, making them capable of acting as proton donors and proton acceptors. Choices A and B represent substances that are specific to either donating or accepting protons. Choice D does not describe a substance's ability to donate or accept protons since neutrality does not inherently involve proton donation or acceptance.

3. A botanist wants to determine if environmental temperature affects root growth. What is the independent variable in this study?

• A. Temperature
• B. Seedlings
• C. Light
• D. Root length

Correct answer: A

Rationale: The correct answer is 'Temperature.' In an experiment, the independent variable is the factor that is deliberately manipulated or changed by the researcher. In this study, the botanist is specifically investigating how environmental temperature affects root growth, making temperature the independent variable. Choice B, 'Seedlings,' and Choice C, 'Light,' are not the independent variables in this context as they are not the factors being intentionally changed or manipulated. Choice D, 'Root length,' is the dependent variable, as it is the outcome that is being measured or observed in response to the changes in the independent variable, temperature.

4. Which of the following antibodies can cross the placenta?

• A. IgA
• B. IgD
• C. IgG
• D. IgM

Correct answer: C

Rationale: The correct answer is IgG. IgG is the only antibody that can cross the placenta, providing passive immunity to the developing fetus. IgA, IgD, and IgM do not cross the placenta. IgA is mainly found in mucosal secretions, IgD is involved in the activation of B cells, and IgM is the first antibody produced in response to an infection, but it does not cross the placental barrier.

5. After water absorption in the large intestine, what waste product remains and is eventually eliminated from the body?

• A. Chyme
• B. Bolus
• C. Glucose
• D. Feces

Correct answer: D

Rationale: The correct answer is D: Feces. After the large intestine absorbs water and electrolytes from digested food material, the waste product that remains is feces. Feces consist of undigested food material, bacteria, and waste products that were not absorbed by the body. Choice A, Chyme, is incorrect as chyme is a semi-fluid mass of partially digested food that moves from the stomach to the small intestine. Choice B, Bolus, is incorrect as bolus refers to a rounded mass of food that is swallowed. Choice C, Glucose, is incorrect as glucose is a simple sugar that serves as a vital energy source for the body and is not a waste product in this context.

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