Nursing Elites

1. Why is the nucleus important in a cell?

• A. It stores the DNA
• B. It supports the cell
• C. It makes protein
• D. It makes energy out of food

Correct answer: A

Rationale: The nucleus is important in a cell because it stores the DNA, which contains the genetic information necessary for the cell's function and replication. This genetic material controls the cell's activities and characteristics. Choices B, C, and D are incorrect because supporting the cell, making proteins, and producing energy are functions typically associated with other cell organelles like the cytoskeleton, ribosomes, and mitochondria, respectively.

2. Which of the following describes the situation where one allele takes a different form from another in a gene?

• A. phenotype
• B. heterozygous
• C. homolog
• D. homozygous

Correct answer: B

Rationale: Heterozygous is the term used to describe the genotype of an individual with two different alleles for a specific gene. In this case, one allele takes a different form from another, resulting in genetic diversity and variation in trait expression. The other choices are incorrect: 'phenotype' refers to the observable traits of an organism, 'homolog' typically refers to chromosomes that are similar in structure, and 'homozygous' describes the genotype where both alleles for a gene are the same.

3. Select the strand of DNA that would match this segment: ACTTGCA

• A. TGAACGT
• B. GACCATG
• C. ACTTGCA
• D. None of the above

Correct answer: A

Rationale: The correct match for the DNA segment ACTTGCA is TGAACGT. In DNA, adenine (A) always pairs with thymine (T), and cytosine (C) always pairs with guanine (G). Therefore, the complementary strand to ACTTGCA should be TGAACGT, making choice A the correct answer. Choice B (GACCATG) does not follow the base pairing rules; hence, it is incorrect. Choice C (ACTTGCA) is the original segment, not its complementary strand. Choice D is incorrect as well because a matching strand does exist.

4. Which cells in the human body lack nuclei?

• A. Nerve cells
• B. Red blood cells
• C. Liver cells
• D. Connective tissue cells

Correct answer: B

Rationale: Red blood cells, also known as erythrocytes, lack nuclei in humans. This absence of a nucleus allows more space for hemoglobin, the protein responsible for carrying oxygen, making red blood cells efficient at their function of oxygen transport in the body. Nerve cells (Choice A), liver cells (Choice C), and connective tissue cells (Choice D) all possess nuclei as they require genetic material for their functions, such as cell signaling, protein synthesis, and structural support.

5. What is represented by this formula: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂?

• A. Glycolysis
• B. Cellular respiration
• C. Photosynthesis
• D. Electronic transport

Correct answer: C

Rationale: The formula represents the process of photosynthesis, where carbon dioxide (CO₂) and water (H₂O) are converted into glucose (C₆H₁₂O₆) and oxygen (O₂) using light energy. This process is essential for plants and some microorganisms to produce food and oxygen. Glycolysis and cellular respiration involve breaking down glucose to produce energy, and the electron transport chain is part of cellular respiration, not photosynthesis.

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