Nursing Elites

1. Binary fission is a type of asexual reproduction. Which of the following occurs during the binary fission process?

• A. The chromosomes bind to the plasma membrane
• B. The chromosomes attach to the spindle formed along the axis
• C. The chromosomes gather in the center of the cell
• D. The chromosomes begin to separate

Correct answer: A

Rationale: The correct answer is A. In binary fission, the chromosomes bind to the plasma membrane before the cell splits into two. This initial step ensures that each daughter cell receives a complete set of genetic material. Choice B is incorrect because the spindle apparatus is characteristic of eukaryotic cell division (mitosis), not prokaryotic binary fission. Choice C is incorrect as chromosomes do not necessarily gather in the center of the cell during binary fission. Choice D is incorrect because the chromosomes do not begin to separate in binary fission; they replicate and then move to opposite ends of the cell before division.

2. The Punnett square shows that one parent carries the recessive gene for a cleft chin (c) while the other parent does not. What percentage of the parents' offspring is predicted to have a cleft chin?

• A. 25%
• B. 50%
• C. 0%
• D. 75%

Correct answer: C

Rationale: The correct answer is 0%. If one parent carries the recessive gene for a cleft chin while the other parent does not, none of the offspring will express the recessive phenotype. This is because in order for a child to have a cleft chin, they would need to inherit the recessive gene from both parents. Therefore, although the offspring could be carriers of the gene, none are predicted to have a cleft chin. Choices A, B, and D are incorrect because the presence of the recessive gene in one parent and its absence in the other would not result in any offspring showing the cleft chin trait.

3. Which of the following organelles is the site of cellular respiration?

• A. Nucleus
• B. Mitochondria
• C. Lysosomes
• D. Ribosomes

Correct answer: B

Rationale: The correct answer is B: Mitochondria. Mitochondria are known as the powerhouse of the cell because they generate most of the cell's supply of ATP through cellular respiration. The other organelles listed, such as the nucleus (choice A), lysosomes (choice C), and ribosomes (choice D), do not play a direct role in cellular respiration. The nucleus contains genetic material, lysosomes are involved in digestion and waste removal, and ribosomes are responsible for protein synthesis.

4. During which stage of photosynthesis is solar energy converted to chemical energy?

• A. During phosphate synthesis
• B. During light reactions
• C. During the Krebs cycle
• D. During the Calvin cycle

Correct answer: B

Rationale: The correct answer is B, during the light reactions. During the light reactions of photosynthesis, solar energy is absorbed by chlorophyll and converted into chemical energy in the form of ATP and NADPH. Choice A is incorrect as phosphate synthesis does not involve the conversion of solar energy. Choice C, the Krebs cycle, is a part of cellular respiration, not photosynthesis. Choice D, the Calvin cycle, is responsible for fixing carbon dioxide into carbohydrates and does not involve the direct conversion of solar energy to chemical energy.

5. What characteristic of water allows for hydrogen bonding between molecules?

• A. Its covalent bonds
• B. Its cohesive properties
• C. Its high specific heat
• D. Its polar nature

Correct answer: D

Rationale: The correct answer is D: Its polar nature. Water is a polar molecule with a partial positive charge on hydrogen atoms and a partial negative charge on oxygen atoms. This polarity allows water molecules to form hydrogen bonds with each other. Choice A, covalent bonds, is incorrect because while water indeed has covalent bonds, they do not directly enable hydrogen bonding. Choice B, cohesive properties, is incorrect as cohesion refers to water's ability to stick to other substances, not the specific characteristic that allows for hydrogen bonding. Choice C, high specific heat, is also incorrect as it refers to water's ability to resist changes in temperature, not its property that leads to hydrogen bonding.

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