Nursing Elites

1. What is a monohybrid cross, and what is the ratio of dominant to recessive gene manifestation?

• A. A cross involving two traits, 9:3:3:1
• B. A cross involving one trait, 3:1
• C. A cross involving two traits, 1:2:1
• D. A cross involving one trait, 1:1

Correct answer: B

Rationale: A monohybrid cross is a genetic cross involving one trait. The ratio of dominant to recessive gene manifestation in the offspring is typically 3:1 when both parents are heterozygous. This ratio is the genotypic ratio, not just the phenotype ratio, where the dominant allele is present in 3 out of 4 offspring, and the recessive allele is present in 1 out of 4 offspring. Choice A is incorrect because it describes a dihybrid cross ratio. Choice C is incorrect as it represents the genotypic ratio for a monohybrid cross involving incomplete dominance. Choice D is incorrect as it does not reflect the typical ratio for a monohybrid cross.

2. Which type of nuclear reaction releases a large amount of energy in a short time?

• A. Radioactivity
• B. Nuclear fission
• C. Nuclear fusion
• D. All of the above

Correct answer: C

Rationale: Nuclear fusion releases a large amount of energy in a short time by combining two light atomic nuclei to form a heavier nucleus. This process is the energy source of the sun and hydrogen bombs. Radioactivity involves the spontaneous emission of particles or energy from an unstable atomic nucleus, while nuclear fission is the splitting of a heavy atomic nucleus into two or more lighter nuclei, also releasing energy. While all the options are types of nuclear reactions, nuclear fusion is specifically known for releasing a large amount of energy rapidly, making it the correct choice in this context. Choices A and B are incorrect as they do not specifically describe the process of releasing a large amount of energy in a short time. Choice D is incorrect because not all the options listed release a large amount of energy in a short time, making it an inaccurate answer.

3. Autoimmune diseases occur when the immune system mistakenly attacks healthy body tissues. What is a potential cause of autoimmune diseases?

• A. Deficiency in essential vitamins and minerals
• B. Exposure to environmental toxins
• C. Breakdown in immune cell self-tolerance mechanisms
• D. All of the above

Correct answer: C

Rationale: Autoimmune diseases result from a breakdown in immune cell self-tolerance mechanisms, leading to the immune system mistakenly attacking healthy body tissues. While deficiencies in essential vitamins and minerals or exposure to environmental toxins can impact overall health, they are not direct causes of autoimmune diseases. Deficiency in essential vitamins and minerals may weaken the immune system, making it more susceptible to various health issues but does not directly cause autoimmune diseases. Exposure to environmental toxins can trigger immune responses, but autoimmune diseases specifically stem from the breakdown of self-tolerance mechanisms within immune cells. Therefore, the correct answer is a breakdown in immune cell self-tolerance mechanisms.

4. What is the term for the small air sacs in the lungs where gas exchange (oxygen and carbon dioxide) takes place?

• A. Bronchi
• B. Alveoli
• C. Trachea
• D. Bronchioles

Correct answer: B

Rationale: The correct answer is B: Alveoli. The alveoli are the small air sacs in the lungs where gas exchange occurs. Oxygen from the air we breathe passes into the bloodstream through the alveoli, while carbon dioxide from the bloodstream passes out of the body through the alveoli. Choice A, Bronchi, are the main airways in the lungs and not the site of gas exchange. Choice C, Trachea, refers to the windpipe, which is a different structure than the alveoli. Choice D, Bronchioles, are smaller airways branching off from the bronchi and are not where gas exchange primarily occurs.

5. What is the recommended daily fiber intake for adults?

• A. 10 grams
• B. 25 grams
• C. 35 grams
• D. 50 grams

Correct answer: B

Rationale: The recommended daily fiber intake for adults is around 25 grams for women and 38 grams for men. Fiber is essential for maintaining a healthy digestive system, preventing constipation, and reducing the risk of chronic diseases such as heart disease and diabetes. Consuming an adequate amount of fiber can also help with weight management and promote overall well-being. Option B is the correct answer based on the recommended daily intake guidelines for adults. Choices A, C, and D are incorrect because they do not align with the established guidelines for fiber intake in adults. 10 grams (choice A) is too low, 35 grams (choice C) is higher than the general recommendation, and 50 grams (choice D) is significantly above the recommended intake, which may lead to digestive issues in some individuals.

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