Nursing Elites

1. What cycle is the sequence of reactions by which most living cells generate energy during aerobic respiration?

• A. Calvin Cycle
• B. Krebs Cycle
• C. Photosynthesis
• D. Fermentation

Correct answer: B

Rationale: The Krebs Cycle is the correct answer. It is a series of reactions occurring in the mitochondria and is a crucial part of aerobic respiration. The Calvin Cycle is a part of photosynthesis, not respiration, making choice A incorrect. Photosynthesis (choice C) is the process by which plants, algae, and some bacteria convert light energy into chemical energy. Fermentation (choice D) is an anaerobic process that does not require oxygen and is not the primary energy-generating pathway during aerobic respiration, so it is incorrect.

2. Which of the following shows how information is transformed to make a protein?

• A. DNA-RNA-protein
• B. gene-chromosome-protein
• C. ATP-amino acid-protein
• D. RNA-DNA-protein

Correct answer: A

Rationale: The correct sequence of events for protein synthesis is that DNA is transcribed into RNA, which is then translated into a protein. This process is known as the central dogma of molecular biology. In this sequence, DNA serves as the template for RNA synthesis (transcription), and the RNA serves as the template for protein synthesis (translation). Choice B is incorrect as genes are segments of DNA that code for proteins, and chromosomes are structures that contain DNA. Choice C is incorrect as ATP is an energy molecule and amino acids are the building blocks of proteins, but they are not directly involved in the synthesis process. Choice D is incorrect because RNA is first transcribed from DNA and then used as a template to produce proteins.

3. In a strand of DNA, you would expect to see adenine paired with ___________.

• A. cytosine
• B. uracil
• C. thymine
• D. guanine

Correct answer: C

Rationale: In a strand of DNA, adenine always pairs with thymine through two hydrogen bonds. This pairing is a fundamental aspect of DNA structure, where adenine and thymine complement each other in the double helix. Choice A (cytosine) is incorrect because adenine does not pair with cytosine in DNA. Choice B (uracil) is incorrect as uracil is found in RNA, not DNA. Choice D (guanine) is incorrect as guanine pairs with cytosine, not adenine, in DNA.

4. What is the typical result of mitosis in humans?

• A. two diploid cells
• B. two haploid cells
• C. four diploid cells
• D. four haploid cells

Correct answer: A

Rationale: The correct answer is A: two diploid cells. Mitosis is a type of cell division that results in two daughter cells, each having the same number of chromosomes as the parent cell. In humans, the typical result of mitosis is the formation of two diploid cells, not haploid or four cells. Choice B, two haploid cells, is incorrect because mitosis produces genetically identical diploid cells. Choices C and D, four diploid cells and four haploid cells, respectively, are incorrect as mitosis results in two daughter cells, not four.

5. In order, from lower to upper, the layers of the atmosphere are:

• A. Exosphere, thermosphere, mesosphere, stratosphere, troposphere
• B. Troposphere, stratosphere, mesosphere, thermosphere, exosphere
• C. Mesosphere, troposphere, stratosphere, thermosphere, exosphere
• D. Thermosphere, troposphere, stratosphere, mesosphere, exosphere

Correct answer: B

Rationale: The correct order of the layers of the atmosphere, from lower to upper, is troposphere, stratosphere, mesosphere, thermosphere, exosphere. The troposphere is the lowest layer where weather phenomena occur. The stratosphere contains the ozone layer, which absorbs and scatters the solar ultraviolet radiation. The mesosphere is where most meteorites burn up upon entering the Earth's atmosphere. The thermosphere is characterized by high temperatures due to the absorption of solar radiation. The exosphere is the outermost layer where the atmosphere transitions into space. Therefore, option B is the correct sequence, as it reflects the ascending order of the Earth's atmospheric layers.

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