Nursing Elites

1. Which of the following nucleobases does not exist in RNA?

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

Correct answer: B

Rationale: The correct answer is 'B: Thymine'. Thymine is a nucleobase found in DNA but is replaced by uracil in RNA. RNA contains Uracil, Cytosine, and Guanine as its nucleobases. Cytosine and Guanine are present in both DNA and RNA, while Thymine is exclusive to DNA and Uracil is specific to RNA.

2. After the Industrial Revolution, the population of peppered moths in England shifted towards more dark moths. This is an example of:

• A. Artificial selection (selective breeding by humans for desired traits)
• B. Natural selection acting on pre-existing variation
• C. Punctuated equilibrium (rapid bursts of evolution)
• D. Lamarckism (inheritance of acquired characteristics)

Correct answer: B

Rationale: The shift in the peppered moth population towards more dark moths in England after the Industrial Revolution exemplifies natural selection acting on pre-existing variation. Initially, light-colored moths were well-camouflaged against lichen-covered tree trunks, but with industrial pollution darkening the tree trunks, dark-colored moths gained a survival advantage. This change reflects how the environment favored dark moths over light ones, illustrating natural selection. The process illustrates how organisms with traits advantageous in a changing environment are more likely to survive and reproduce, leading to the prevalence of those traits in the population over time. The choices of artificial selection (A), punctuated equilibrium (C), and Lamarckism (D) are not applicable in this scenario. Artificial selection involves intentional breeding by humans, punctuated equilibrium refers to rapid bursts of evolution followed by periods of stability, and Lamarckism suggests the inheritance of acquired characteristics, none of which align with the observed shift in moth populations based on environmental changes.

3. Which of the following is the main organ responsible for regulating blood pressure?

• A. Heart
• B. Kidneys
• C. Adrenal glands
• D. Pituitary gland

Correct answer: B

Rationale: The kidneys play a crucial role in regulating blood pressure through various mechanisms. One of the key ways the kidneys regulate blood pressure is by controlling the volume of blood in the body. They do this by adjusting the amount of water and sodium excreted in the urine. The renin-angiotensin-aldosterone system, primarily controlled by the kidneys, also plays a significant role in blood pressure regulation. This system helps to maintain blood pressure by regulating blood volume and systemic vascular resistance. While the heart, adrenal glands, and pituitary gland are involved in various aspects of the cardiovascular and endocrine systems, the kidneys are the main organ responsible for regulating blood pressure.

4. What is the atomic number of an atom?

• A. The number of protons in an atom
• B. The number of neutrons in an atom
• C. The number of electrons in an atom
• D. The sum of protons and neutrons

Correct answer: A

Rationale: The correct answer is A: The atomic number of an atom is the number of protons in its nucleus. This number uniquely identifies the element, as each element has a distinct number of protons. Neutrons and electrons play roles in the atom's structure and stability, but the atomic number specifically refers to the number of protons. Choice B (The number of neutrons in an atom) is incorrect because the atomic number does not include neutrons; it only represents the number of protons. Choice C (The number of electrons in an atom) is incorrect because the atomic number is not related to the number of electrons, which can vary in different atomic configurations. Choice D (The sum of protons and neutrons) is incorrect because it refers to the mass number of an atom, which is the total number of protons and neutrons in the nucleus, not just the protons.

5. In the following sentence, which part of speech does the word 'capacity' function as?

• A. Verb
• B. Noun
• C. Adverb
• D. Pronoun

Correct answer: B

Rationale: In the sentence, 'capacity' is used to refer to the maximum amount that something can contain or produce, making it a noun. It is not functioning as a verb (choice A), as it is not describing an action. It is not an adverb (choice C) because it is not modifying a verb, adjective, or another adverb. Additionally, it is not a pronoun (choice D) because it is not replacing a noun or noun phrase. Therefore, the correct answer is 'B: Noun.'

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