Nokea
Monozygotic (MZ) twins share _________ percent of their genes.
- A. 100
- B. 75
- C. 50
- D. 25
Correct Answer: A
Rationale: Monozygotic (MZ) twins share 100% of their genes because they originate from the same fertilized egg that splits into two, resulting in identical genetic material for both twins. Choice B (75%) is incorrect as it implies a partial genetic similarity, which is not the case for MZ twins. Choice C (50%) is incorrect as it suggests half of the genes are shared, which is applicable to dizygotic (DZ) twins, not MZ. Choice D (25%) is incorrect as it indicates minimal genetic sharing, which is not true for MZ twins.
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Before meiosis, a sperm cell:
- A. contains 46 chromosomes.
- B. contains two X chromosomes.
- C. is significantly larger than an egg cell.
- D. contains both an X and a Y chromosome.
Correct Answer: A
Rationale: Before meiosis, a sperm cell contains 46 chromosomes. This is because sperm cells, like other somatic cells, have a diploid number of chromosomes. During meiosis, the number of chromosomes is halved to 23 to combine with an egg cell during fertilization. Choice B is incorrect because a sperm cell carries either an X or a Y chromosome, not both (Choice D). Choice C is incorrect as sperm cells are generally smaller than egg cells, which is an adaptation that aids in motility and penetration of the egg during fertilization.
A nurse is planning to teach a group of clients who are breastfeeding after returning to work. Which of the following instructions should the nurse include in the teaching?
- A. "Thawed breast milk can be refrigerated for up to 24 hours."
- B. "Breast milk can be stored in a deep freezer for 12 months."
- C. "Breast milk can be stored at room temperature for up to 4 hours."
- D. "Thawed breast milk that is unused cannot be refrozen."
Correct Answer: B
Rationale: The correct answer is B: "Breast milk can be stored in a deep freezer for 12 months." This instruction is important for mothers returning to work to ensure a long-term storage option for breast milk. Choice A is incorrect because thawed breast milk should be used within 24 hours if stored in the refrigerator. Choice C is incorrect as breast milk can be kept at room temperature for only up to 4 hours. Choice D is incorrect as thawed breast milk that is unused should not be refrozen due to safety concerns.
A newborn is 1 hour old with a respiratory rate of 50/min, a heart rate of 130/min, and an axillary temperature of 36.1°C (97°F). Which of the following actions should be taken?
- A. Give the newborn a warm bath.
- B. Apply a cap to the newborn's head.
- C. Reposition the newborn.
- D. Obtain an oxygen saturation level.
Correct Answer: B
Rationale: Applying a cap to the newborn's head is the correct action in this scenario. Newborns are at risk of heat loss due to their high surface area to volume ratio, and maintaining their body temperature is crucial to prevent hypothermia. Giving a warm bath can further increase heat loss and is not recommended. Repositioning the newborn may not address the primary concern of temperature regulation. While monitoring oxygen saturation is important, addressing thermal regulation takes precedence in this situation.
An individual's phenotype reflects both genetic and environmental influences.
- A. phenotype
- B. chromosome
- C. allele
- D. genotype
Correct Answer: A
Rationale: The correct answer is A: phenotype. A phenotype is the observable characteristics of an individual, which result from the interaction of their genotype with the environment. This interaction between genetics and the environment determines how genes are expressed and how traits are manifested in an individual. Choices B, C, and D are incorrect because chromosomes, alleles, and genotypes are components of an individual's genetic makeup, but they do not directly reflect the observable traits influenced by both genetics and the environment.
The nurse has received a report regarding a client in labor. The woman's last vaginal examination was recorded as 3 cm, 30%, and -2. What is the nurse's interpretation of this assessment?
- A. Cervix is effaced 3 cm and dilated 30%; the presenting part is 2 cm above the ischial spines.
- B. Cervix is dilated 3 cm and effaced 30%; the presenting part is 2 cm above the ischial spines.
- C. Cervix is effaced 3 cm and dilated 30%; the presenting part is 2 cm below the ischial spines.
- D. Cervix is dilated 3 cm and effaced 30%; the presenting part is 2 cm below the ischial spines.
Correct Answer: B
Rationale: The correct interpretation of the assessment provided is that the cervix is dilated 3 cm and effaced 30%; the presenting part is 2 cm above the ischial spines. In the given assessment, the measurements are ordered as dilation, effacement, and station. Choice A is incorrect as it wrongly places the presenting part below the ischial spines. Choice C is incorrect because it places the presenting part below the ischial spines. Choice D is also incorrect as it incorrectly states that the presenting part is below the ischial spines, even though it correctly mentions the dilation and effacement of the cervix.