Nursing Elites

1. The number of protons in an atom determines its:

• A. Mass number
• B. Atomic number
• C. Atomic weight
• D. Valence electron count

Correct answer: B

Rationale: The number of protons in an atom is known as the atomic number. The atomic number uniquely identifies an element and determines its position on the periodic table. It is a fundamental property of an element and directly influences its chemical behavior and interactions. The mass number, on the other hand, is the sum of protons and neutrons in the nucleus of an atom, not just protons. Atomic weight is the average mass of an element's isotopes considering their relative abundance, not solely based on the number of protons. Valence electron count refers to the number of electrons in the outermost energy level of an atom, influencing its ability to form bonds and participate in chemical reactions, but it is not determined by the number of protons in the atom.

2. Blood type is a trait determined by multiple alleles, with IA coding for A blood, IB coding for B blood, and i coding for O blood being recessive. If an individual with A heterozygosity and an O individual have a child, what is the probability that the child will have A blood?

• A. 25%
• B. 50%
• C. 75%
• D. 100%

Correct answer: B

Rationale: When an A heterozygote individual (IAi) and an O individual (ii) have a child, there are four possible combinations of alleles that the child can inherit: IA from the A parent and i from the O parent; IA from the A parent and i from the O parent; i from the A parent and i from the O parent; i from the A parent and i from the O parent. Out of these combinations, 50% of the offspring will inherit the A allele from the A parent, resulting in A blood type. Therefore, the correct answer is 50%. Choice A is incorrect because the probability is not 25%. Choice C is incorrect as it overestimates the likelihood. Choice D is incorrect as it suggests a certainty which is not the case in genetics.

3. Which hormone is responsible for regulating the body's metabolism?

• A. Insulin
• B. Thyroxine
• C. Melatonin
• D. Adrenaline

Correct answer: B

Rationale: Thyroxine, also known as T4, is produced by the thyroid gland and plays a vital role in regulating the body's metabolism. Insulin is not responsible for regulating metabolism; instead, it helps regulate blood sugar levels. Melatonin is involved in regulating sleep-wake cycles, not metabolism. Adrenaline, also known as epinephrine, is a stress hormone that prepares the body for fight or flight responses, not primarily involved in metabolic regulation.

4. What causes stretch marks?

• A. The epidermis layer becomes inflamed
• B. The dermis layer becomes inflamed
• C. The dermis layer tears due to rapid stretching
• D. Sebaceous glands become clogged

Correct answer: C

Rationale: Stretch marks occur when the dermis layer tears due to rapid stretching of the skin. This tearing leads to the appearance of stretch marks, which are often red or purple at first and then fade to a silvery-white color over time. Inflammation of the dermis or clogging of sebaceous glands are not directly related to the formation of stretch marks. Therefore, choices A, B, and D are incorrect as they do not describe the actual cause of stretch marks.

5. An uncharged atom has an electron configuration of 1s² 2s² 2p⁶ 3s² and a mass number of 14. How many protons does it have?

• A. 14
• B. 6
• C. 8
• D. 12

Correct answer: B

Rationale: The number of protons in an atom is determined by the atomic number, which is equal to the number of protons in the nucleus. The electron configuration given corresponds to carbon (C) with 6 protons. The atomic number of an element is the same as the number of protons in its nucleus, so in this case, the atom has 6 protons. Choices A, C, and D are incorrect because they do not correspond to the correct number of protons for an atom with the given electron configuration and mass number. Therefore, option B, 6 protons, is the correct answer.

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