Nursing Elites

1. Select the option that best shows complementary base pairing in DNA:

• A. A and G
• B. A and C
• C. A and A
• D. A and T

Correct answer: D

Rationale: The correct answer is D. A purine (A) must pair with a pyrimidine (T) in DNA. This eliminates options A and C as they do not follow the rule of complementary base pairing. Adenine (A) always pairs with thymine (T) due to their specific shape and bonding properties in DNA structure. Choice B is incorrect because adenine does not pair with cytosine in DNA.

2. What molecule is primarily responsible for providing energy to the cell?

• A. ATP
• B. DNA
• C. ADP
• D. Glycogen

Correct answer: A

Rationale: Correct! ATP (Adenosine Triphosphate) is the main molecule that stores and provides energy for cellular activities. ATP is known as the energy currency of the cell, where energy released from the breakdown of nutrients is stored in the high-energy phosphate bonds of ATP. Choices B, C, and D are incorrect because DNA carries genetic information, ADP is the precursor of ATP, and glycogen is a polysaccharide used for energy storage, not direct energy provision.

3. What process do cells in the tip of a plant’s root undergo to increase in number?

• A. Meiosis
• B. Cytokinesis
• C. Fractioning
• D. Mitosis

Correct answer: D

Rationale: Cells in the tip of a plant's root undergo the process of mitosis to increase in number. Mitosis is a type of cell division that results in two daughter cells with the same number of chromosomes as the parent cell. This process allows for growth and maintenance of tissues in plants by producing new cells through division. Choice A, Meiosis, is incorrect as meiosis is a type of cell division that reduces the number of chromosomes in cells to produce gametes. Choice B, Cytokinesis, is incorrect as it is the division of the cytoplasm following cell division. Choice C, Fractioning, is not a biological process related to cell division.

4. Why do high-salt content foods not require refrigeration to prevent spoilage?

• A. Osmosis
• B. Diffusion
• C. Active transport
• D. Passive transport

Correct answer: A

Rationale: Osmosis is the natural process that prevents high-salt content foods from spoiling without the need for refrigeration. Osmosis involves the movement of water across a semi-permeable membrane from an area of lower solute concentration (water) to an area of higher solute concentration (salt). In high-salt content foods, the salt acts as a preservative by drawing moisture out of bacteria or other microorganisms, making it difficult for them to survive and spoil the food. This process helps in preserving the food and preventing spoilage even without refrigeration. Choices B, C, and D are incorrect because they do not involve the specific mechanism of water movement in response to the salt concentration in high-salt content foods.

5. How should a researcher test the hypothesis that radiation from cell phones is significant enough to raise the temperature of water in a test tube?

• A. Dial a cell phone that rests beside a test tube of water, let it ring for two minutes, and record the temperature of the water before and after the two-minute interval.
• B. Dial a cell phone that rests beside a test tube of water; let it ring for two, three, and four minutes; and record the temperature of the water before and after each interval.
• C. Use three different brands of cell phone; dial each as it rests beside its own test tube of water, let it ring for two minutes, and record the temperature of the water before and after the two-minute interval.
• D. Use three different brands of cell phone, dial each and let one ring for two minutes, one for three minutes, and one for four minutes; record the temperature of the water before and after each interval.

Correct answer: A

Rationale: To test the hypothesis that radiation from cell phones raises the temperature of water in a test tube, the most appropriate method is to dial a cell phone next to a test tube of water, let it ring for a consistent two-minute interval, and record the temperature before and after. Choice A is correct because it provides a controlled approach to isolate the impact of the phone's radiation on the water temperature. Choices B, C, and D introduce additional variables that could confound the results. Choice B varies the duration of exposure, making it difficult to attribute temperature changes specifically to the radiation. Choice C introduces the factor of different cell phone brands, which could introduce variability not related to radiation. Choice D also varies exposure times and introduces the factor of multiple phone brands, making it harder to determine the direct impact of cell phone radiation on water temperature. Therefore, choice A is the most suitable option for this experiment.

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