Nursing Elites

1. What is the magnification of an ocular lens on a microscope?

• A. 4x
• B. 10x
• C. 40x
• D. 100x

Correct answer: B

Rationale: The magnification of an ocular lens on a microscope is typically 10x, which is considered standard for most microscopes. Ocular lenses are designed to magnify the image produced by the objective lens further. Choices A, C, and D are incorrect because they do not represent the standard magnification of an ocular lens. A magnification of 4x, 40x, or 100x would not be typical for an ocular lens in a microscope.

2. What are the three main events of the haploid cell cycle?

• A. DNA replication, mitosis, and cytokinesis
• B. DNA replication, meiosis, and cytokinesis
• C. DNA replication, cytokinesis, and degradation
• D. Mitosis, meiosis, and apoptosis

Correct answer: A

Rationale: In the haploid cell cycle, the three main events are DNA replication, where the cell's genetic material is duplicated; mitosis, which is the division of the nucleus to ensure each daughter cell receives a complete set of chromosomes; and cytokinesis, the division of the cell cytoplasm to separate the two daughter cells. Meiosis is not part of the haploid cell cycle as it occurs in diploid cells to produce haploid gametes. Apoptosis is a process of programmed cell death and is not a routine event in the cell cycle. Therefore, the correct answer is A. Choices B, C, and D are incorrect as meiosis and apoptosis are not part of the haploid cell cycle, and degradation is not a typical event in the cell cycle.

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. Which of the following animals would have the least energy efficiency in nutrient consumption?

• A. Cow
• B. Caterpillar
• C. Coyote
• D. Cricket

Correct answer: A

Rationale: Cows are ruminant animals that have multiple stomachs and require large amounts of food to digest and convert into energy. They have lower energy efficiency compared to insects like caterpillars, coyotes, and crickets, which have more efficient nutrient consumption processes. The digestive system and metabolic functions of cows result in them having the least energy efficiency in nutrient consumption among the given choices. Caterpillars, coyotes, and crickets have more efficient nutrient consumption processes, making them more energy-efficient than cows.

5. Which statement is untrue?

• A. RNA is single-stranded.
• B. RNA contains uracil.
• C. DNA codes for proteins.
• D. DNA cannot be altered.

Correct answer: D

Rationale: DNA can be altered through various processes such as mutations, genetic engineering, and epigenetic modifications. Changes in DNA can occur naturally or through external influences, leading to variations in the genetic code. Therefore, the statement that DNA cannot be altered is untrue. Choices A, B, and C are true statements. RNA is indeed single-stranded, RNA contains uracil instead of thymine, and DNA serves as a template for protein synthesis.

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