Which of the following statements is a symptom of cystic fibrosis in children?

Correct Answer: B

Rationale: The correct answer is B. Cystic fibrosis is a genetic disorder that causes the body to produce thick, sticky mucus. This mucus can clog the airways in the lungs and obstruct the pancreas, leading to severe respiratory and digestive problems. Choice A is incorrect because uncontrollable muscle movements and personality changes are not typical symptoms of cystic fibrosis. Choice C is incorrect because cystic fibrosis does not directly cause red blood cells to clump together and obstruct small blood vessels. Choice D is incorrect because cystic fibrosis primarily affects the respiratory and digestive systems, not the central nervous system.

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.

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.

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.

Correct Answer: B

Rationale: The correct answer is mesoderm. The mesoderm is the middle layer of the embryo that gives rise to the bones, muscles, and other connective tissues. The neural tube (choice A) develops into the nervous system, not bones and muscles. The ectoderm (choice C) forms the skin and nervous system, not bones and muscles. The umbilical cord (choice D) is a structure that connects the developing fetus to the placenta; it is not a layer of the embryo that gives rise to bones and muscles.