Nursing Elites

1. Which of the following is true of homozygous traits?

• A. They are haploid
• B. They are denoted AA
• C. They are denoted aa
• D. They are denoted Aa

Correct answer: B

Rationale: Homozygous traits have two identical forms of the gene, either both dominant (AA) or both recessive (aa). Therefore, choices B and C are true for homozygous traits. Choice A is incorrect because being haploid refers to having a single set of chromosomes, not necessarily homozygous traits. Choice D is incorrect as homozygous traits have identical alleles, so they are not denoted as Aa.

2. Imagine that two parents both carry the recessive gene for cystic fibrosis. Any homozygous recessive offspring will manifest the disease. What percentage of the offspring is predicted to be carriers but not manifest the disease?

• A. 0%
• B. 25%
• C. 50%
• D. 100%

Correct answer: B

Rationale: When both parents carry the recessive gene for cystic fibrosis (homozygous recessive), there is a 25% chance for each offspring to inherit two recessive alleles and, therefore, manifest the disease. There is also a 50% chance for each offspring to inherit one recessive allele and one dominant allele, making them carriers of the disease but not manifest it. Therefore, 25% of the offspring are predicted to be carriers but not manifest the disease. Choice A (0%) is incorrect because there is a portion of offspring that will be carriers. Choice C (50%) is incorrect as this percentage corresponds to carriers who will not manifest the disease. Choice D (100%) is incorrect as not all offspring will be carriers and not manifest the disease.

3. Which animal has an open transport system?

• A. Grasshopper
• B. Earthworm
• C. Dolphin
• D. Chicken

Correct answer: B

Rationale: The correct answer is B: Earthworm. Earthworms have an open circulatory system, meaning their blood and interstitial fluid are not enclosed in blood vessels. Instead, the blood flows freely within the body cavity, allowing for direct exchange of nutrients and waste products with surrounding tissues. This lack of a closed transport system is a characteristic feature of earthworms. Choices A, C, and D are incorrect because grasshoppers, dolphins, and chickens have closed circulatory systems where the blood is enclosed within blood vessels, unlike earthworms.

4. Which molecule is primarily responsible for storing energy in cells?

• A. Glucose
• B. ATP
• C. Fatty acids
• D. Starch

Correct answer: B

Rationale: ATP is the correct answer because it is the molecule responsible for storing and providing energy in cells. Glucose is a source of energy but not primarily for storage. Fatty acids are more involved in energy production through oxidation. Starch is a polysaccharide used for energy storage in plants.

5. 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.

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