Nursing Elites

1. Dizygotic (DZ) twins share _________ percent of their genes.

• A. 100
• B. 75
• C. 50
• D. 25

Correct answer: C

Rationale: Dizygotic (DZ) twins share approximately 50% of their genes. This is because dizygotic twins, also known as fraternal twins, originate from two separate fertilized eggs and share similar genetic similarity to regular siblings. Choice A (100%) is incorrect because if twins shared 100% of their genes, they would be identical twins (monozygotic). Choice B (75%) is incorrect as it is not the typical genetic similarity seen in dizygotic twins. Choice D (25%) is incorrect as it represents a significantly lower genetic similarity than what is observed in dizygotic twins.

2. Are sperm much larger than ova?

• A. TRUE
• B. FALSE
• C. Sometimes
• D. Always

Correct answer: B

Rationale: The correct answer is B: FALSE. Ova, also known as eggs, are actually the largest cells in the human body, while sperm are significantly smaller. This size difference is due to the different functions of the two gametes. Sperm are specialized for motility to reach and fertilize the egg, while ova contain nutrients and cellular machinery needed for fertilization and early embryonic development. Choices A, C, and D are incorrect because sperm are not larger than ova; they are much smaller in size.

3. A premature infant with respiratory distress syndrome (RDS) receives artificial surfactant. How does the nurse explain surfactant therapy to the parents?

• A. “Surfactant improves the ability of your baby’s lungs to exchange oxygen and carbon dioxide.”
• B. “The drug keeps your baby from requiring too much sedation.”
• C. “Surfactant is used to reduce episodes of periodic apnea.”
• D. “Your baby needs this medication to fight a possible respiratory tract infection.”

Correct answer: A

Rationale: Artificial surfactant can be administered as an adjunct to oxygen and ventilation therapy for premature infants with respiratory distress syndrome (RDS). It helps improve respiratory compliance by aiding in the exchange of oxygen and carbon dioxide until the infant can produce enough surfactant naturally. The correct explanation to the parents would be that surfactant therapy enhances the baby’s lung function by facilitating the exchange of oxygen and carbon dioxide. Choice B is incorrect because surfactant therapy does not affect sedation needs. Choice C is inaccurate as surfactant is not used to reduce episodes of periodic apnea. Choice D is incorrect as surfactant is not administered to fight respiratory tract infections; it specifically targets improving lung function in RDS.

4. Monozygotic (MZ) twins are known as fraternal twins.

• A. TRUE
• B. FALSE
• C. Possibly
• D. Never

Correct answer: B

Rationale: The correct answer is B: 'FALSE.' Monozygotic (MZ) twins are identical twins, not fraternal. Fraternal twins are dizygotic (DZ). The statement in the question is incorrect as MZ twins are genetically identical, while fraternal twins actually refer to dizygotic twins who develop from two separate fertilized eggs. Therefore, monozygotic twins are not known as fraternal twins, making option B the correct choice. Options A, C, and D are incorrect as they do not accurately describe the relationship between monozygotic and fraternal twins.

5. What causes sickle-cell anemia?

• A. A chromosomal abnormality.
• B. A single segment found only on the Y chromosome.
• C. A recessive gene.
• D. A decrease in estrogen levels.

Correct answer: C

Rationale: Sickle-cell anemia is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. The correct answer is C. Choice A is incorrect because sickle-cell anemia is not primarily caused by a chromosomal abnormality. Choice B is incorrect as the condition is not linked to a single segment found only on the Y chromosome. Choice D is unrelated as it mentions a decrease in estrogen levels, which is not a cause of sickle-cell anemia.

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