Nursing Elites

1. Choose the two bases that have two carbon rings:

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

Correct answer: A

Rationale: Adenine and guanine have two carbon rings and are known as purines. These bases are found in nucleic acids such as DNA and RNA. Adenine (option A) and guanine (option D) are the correct choices as they both have two carbon rings in their molecular structure. Cytosine (option B) and thymine (option C) have a single carbon ring each, making them incorrect choices for bases with two carbon rings.

2. Why is DNA important for metabolic activities of the cell?

• A. It controls the synthesis of enzymes.
• B. It stabilizes the cell wall.
• C. It initiates cell division.
• D. It prevents diffusion of nutrients.

Correct answer: A

Rationale: The correct answer is A. DNA plays a crucial role in metabolic activities by controlling the synthesis of enzymes. Enzymes are the biological catalysts that regulate and facilitate metabolic reactions within the cell. Choice B is incorrect because DNA is not involved in stabilizing the cell wall; that role is usually associated with other components like the cell membrane. Choice C is incorrect as cell division is primarily regulated by different processes and molecules, not directly by DNA. Choice D is incorrect because DNA is not related to preventing the diffusion of nutrients; instead, it is involved in coding for proteins that aid in various cellular functions.

3. What are saturated fats saturated with?

• A. Hydrogen atoms
• B. Carbon atoms
• C. Oxygen atoms
• D. Nitrogen atoms

Correct answer: A

Rationale: Saturated fats are saturated with hydrogen atoms. This means that each carbon atom in the fatty acid chains forming saturated fats is bonded to as many hydrogen atoms as possible. This saturation results in the fatty acid chains being straight and closely packed together, making saturated fats solid at room temperature. Choice B (Carbon atoms), C (Oxygen atoms), and D (Nitrogen atoms) are incorrect because saturated fats are specifically saturated with hydrogen atoms, not carbon, oxygen, or nitrogen atoms.

4. Why is polarity the most important characteristic of water?

• A. the results of the polarity are hydrogen bonding, a high specific heat value, and its versatile solvent properties
• B. the results of the polarity are covalent bonding, a low specific heat value, and its versatile solvent properties
• C. the results of the polarity are ionic bonding, a high specific heat value, and its versatile solvent properties
• D. the results of the polarity are hydrogen bonding, a low specific heat value, and its versatile solvent properties

Correct answer: A

Rationale: Polarity is the most important characteristic of water because it results in hydrogen bonding, a high specific heat value, and its versatile solvent properties. These unique properties enable water to form hydrogen bonds with other substances, resist temperature changes, and dissolve a wide variety of solutes, making it essential for life processes. Choice B is incorrect because water exhibits hydrogen bonding, not covalent bonding. Choice C is incorrect as water does not form ionic bonds. Choice D is incorrect because water has a high, not low, specific heat value, which is vital for its role in temperature regulation.

5. What event occurs during telophase?

• A. The nuclear envelope disappears.
• B. Organelles double in number.
• C. Chromosomes separate.
• D. Two nuclei are formed.

Correct answer: D

Rationale: During telophase, the final stage of mitosis, the separated chromosomes reach opposite poles of the cell. At this stage, a new nuclear envelope forms around each set of chromosomes, creating two distinct nuclei. This marks the completion of cell division. Choices A, B, and C are incorrect because the disappearance of the nuclear envelope typically occurs during prophase, organelles do not double in number during telophase, and chromosomes separate during anaphase, not telophase.

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