When teaching a class about trisomy 21, the instructor would identify the cause of this disorder as:

Correct Answer: A

Rationale: Trisomy 21, also known as Down syndrome, is caused by nondisjunction, which is an error in cell division that leads to the presence of an extra chromosome 21. This additional chromosome alters the normal genetic makeup, resulting in the characteristics associated with Down syndrome. Therefore, the correct answer is nondisjunction (Choice A). Choices B, C, and D are incorrect because Trisomy 21 is not caused by X-linked recessive inheritance, genomic imprinting, or autosomal dominant inheritance. Understanding the specific genetic mechanism involved in Trisomy 21 is crucial for grasping the basis of this chromosomal disorder.

Correct Answer: D

Rationale: Closure of the cleft palate is recommended before the age of 2 to prevent the development of faulty speech patterns. Performing surgery at a younger age helps avoid speech difficulties that may arise if the repair is delayed. Choice A is incorrect as it focuses on fear, not the developmental aspect. Choice B is incorrect as the eruption of molars is not the primary reason for early surgery. Choice C is incorrect because the difficulty of repair is not solely related to the width of the palate but also to speech development.

Correct Answer: C

Rationale: In cases where child abuse is suspected, it is crucial to prioritize the safety and well-being of the child. Advising the parents that the child needs to be transported allows for the child to receive necessary medical care without immediate confrontation. Calling the police to have the parents arrested (Choice B) may escalate the situation and should only be done after ensuring the child's safety. Informing the parents of suspicions (Choice A) may potentially place the child at further risk if the parents are the abusers. Transporting the child to the hospital regardless of the parents' wishes (Choice D) could lead to legal and ethical complications; it is important to involve the appropriate authorities and handle the situation with sensitivity and care.

Correct Answer: B

Rationale: The correct answer is B: Rolls over. At 6 months, most infants can roll over, increasing the risk of falls. It is important to emphasize to the parent the need for careful supervision to prevent accidents. While choices A, C, and D are also milestones in infant motor development, rolling over at this age poses a higher risk of accidents due to the increased mobility and potential for falls.

Correct Answer: A

Rationale: The American Academy of Pediatrics recommends the intramuscular polio vaccine because it has a better safety profile compared to the oral vaccine. Choice B is incorrect because the AAP specifically recommends the intramuscular vaccine over the oral vaccine. Choice C is incorrect as cost is not the primary reason for preferring the intramuscular vaccine. Choice D is incorrect as the recommendation is based on safety rather than the immunocompromised status of the infant or family members.

Correct Answer: D

Rationale: Severe coughing spells are a hallmark clinical manifestation of pertussis. Pertussis, also known as whooping cough, is characterized by paroxysms of rapid, consecutive coughs followed by a distinctive 'whoop' sound as the patient gasps for air. This intense coughing can lead to vomiting, exhaustion, and sometimes a characteristic 'whoop' sound. Inspiratory stridor (Choice B) is more commonly associated with croup, not pertussis. Nasal congestion (Choice C) is not a typical feature of pertussis. While a cough is present in pertussis, the specific type of cough described in Choice A (dry, hacking cough) is not the predominant feature observed in pertussis.

Correct Answer: A

Rationale: The correct statement should be, 'We should give this drug after he eats something.' Prednisone should be administered with food to help prevent gastrointestinal upset. Choice B is correct as monitoring for infections is important due to prednisone's immunosuppressive effects. Choice C is correct as prednisone should not be stopped suddenly to prevent withdrawal symptoms. Choice D is correct as weight gain is a common side effect of prednisone.

Correct Answer: C

Rationale: The correct answer is C. In fluid replacement therapy for burns, it is crucial to administer most of the volume during the first 8 hours to prevent shock and maintain perfusion. This rapid administration is essential to stabilize the child's condition. Choices A and B are incorrect because the initial fluid replacement in burns typically involves administering crystalloids, not colloids, and the fluid replacement is generally calculated based on the extent of the burn injury, not the type of burn. Choice D is incorrect as monitoring hourly urine output to achieve less than 1 mL/kg/hr is not recommended in burn patients; instead, urine output should be monitored to achieve 1-2 mL/kg/hr in children to ensure adequate renal perfusion.

Correct Answer: C

Rationale: Scheduling the visit at a time that is convenient for the family is the most appropriate choice. This ensures that the family is receptive and available, making the visit more productive. Choice A is incorrect because the presence of the husband may be important for support and decision-making. Choice B focuses solely on the mother and the infant's feeding time, which may not align with the family's overall availability. Choice D is incorrect as it emphasizes the nurse's convenience rather than the family's, which may not lead to an effective visit.