Nursing Elites

1. What is the mass number of an element?

• A. The number of protons in an atom's nucleus.
• B. The number of neutrons in an atom's nucleus.
• C. The number of electrons in an atom's valence shell.
• D. The number of isotopes of an element.

Correct answer: B

Rationale: The mass number of an element represents the total number of protons and neutrons in an atom's nucleus. It specifically focuses on the number of neutrons in an atom's nucleus, which contributes to the overall mass of the atom. Therefore, the mass number is not solely determined by the number of protons, electrons, or isotopes. Choice A is incorrect because it refers to the atomic number, which is the number of protons in an atom's nucleus. Choice C is incorrect as the number of electrons in the valence shell is related to the atom's reactivity and bonding behavior, not the mass number. Choice D is incorrect because the mass number does not represent the number of isotopes of an element, but rather the sum of protons and neutrons in an atom's nucleus. Thus, option B, the number of neutrons in an atom's nucleus, is the correct choice.

2. When a certain plant is introduced into an area, and the population of a certain insect species declines, what can be concluded from this?

• A. The plant is toxic to the insect in question.
• B. The plant competes with and drives out plants that the insect feeds on.
• C. The insect population was declining anyway; the fact that it happened when the plant was introduced is a coincidence.
• D. All of these explanations may be possible; further investigation is necessary to determine which is true.

Correct answer: D

Rationale: The given scenario presents multiple possible explanations for the decline in the insect population with the introduction of a particular plant. It could be due to the plant being toxic to the insect (Option A), competing with and driving out plants that the insect feeds on (Option B), or the decline could be coincidental with the plant introduction as the insect population was already decreasing (Option C). Without further investigation and evidence, it is not possible to definitively determine which explanation is correct. Therefore, all of these possibilities may be true, and thorough investigation is necessary to reach a conclusive conclusion.

3. Which of the following are the reproductive cells produced by meiosis?

• A. Genes
• B. Alleles
• C. Chromatids
• D. Gametes

Correct answer: D

Rationale: The correct answer is D. Gametes are the reproductive cells produced by meiosis. Meiosis is the cell division process that results in the formation of gametes, which are sperm cells in males and egg cells in females. Genes (A), alleles (B), and chromatids (C) are not the reproductive cells produced by meiosis. Genes are units of heredity, alleles are different forms of a gene, and chromatids are duplicated chromosomes involved in cell division.

4. Which of the following types of muscle tissue is found attached to bones and allows for voluntary movement?

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

Correct answer: C

Rationale: The correct answer is C: Skeletal muscle. Skeletal muscle is attached to bones and allows for voluntary movement, such as walking, running, and lifting objects. Smooth muscle, found in the walls of internal organs and blood vessels, is responsible for involuntary movements. Cardiac muscle is specific to the heart and controls involuntary contraction. Connective tissue, on the other hand, provides support and connects different structures in the body, but it is not responsible for voluntary movement like skeletal muscle.

5. Which property of a substance resists a change in its shape?

• A. Density
• B. Mass
• C. Inertia
• D. Elasticity

Correct answer: D

Rationale: Elasticity refers to a material's ability to resist deformation and return to its original shape after stress is applied. It is the property that resists a change in shape. Density is the mass per unit volume of a substance. Mass is the amount of matter in an object, while inertia is the tendency of an object to resist changes in its state of motion. Viscosity, not mentioned in the question, is the resistance of a fluid to flow, not shape change.

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