Correct Answer: D

Rationale: On the first postpartum day, the nurse is most likely to find the breasts filling and secreting colostrum. Colostrum secretion is common as the body prepares for breastfeeding in the initial days after delivery. Choice A is incorrect as breasts are not typically very tender immediately postpartum. Choice B is incorrect as an immediate let-down response is more related to lactation rather than the first postpartum day. Choice C is incorrect as the breasts typically undergo changes, such as filling with colostrum, after delivery.

Correct Answer: A

Rationale: The correct answer is A: codominance. Codominance refers to a genetic scenario where both alleles in a gene pair are fully expressed, leading to a phenotype that displays traits from both alleles equally. This is distinct from incomplete dominance where the traits blend. Choices B, C, and D are incorrect. Preponderance does not specifically relate to the expression of alleles. Ascendance and concurrence do not describe the genetic concept of codominance where both alleles are fully expressed.

Correct Answer: A

Rationale: The correct process that happens during mitosis is the breaking apart, replication, and division of DNA strands into two new cells, each with the same number of chromosomes as the original cell. Choice B is incorrect because it describes base pairing in DNA, not a process specific to mitosis. Choice C is incorrect as the creation of sperm and ova cells is related to meiosis, not mitosis. Choice D is incorrect because chromosomes are not created during mitosis; they are replicated and divided equally between the daughter cells.

Correct Answer: D

Rationale: In pregnant women with cardiac problems, signs of cardiac decompensation include dyspnea, crackles, an irregular, weak, and rapid pulse, rapid respirations, a moist and frequent cough, generalized edema, increasing fatigue, and cyanosis of the lips and nailbeds. Choice A is incorrect as a regular heart rate and hypertension are not typically associated with cardiac decompensation. Choice B is incorrect as increased urinary output and dry cough are not indicative of cardiac decompensation, only tachycardia is. Choice C is incorrect as bradycardia and hypertension are not typically seen in cardiac decompensation; dyspnea is a critical sign instead.

Correct Answer: D

Rationale: The correct answer is D. The likelihood of having a child with Down's syndrome increases as the age of the parents increases, particularly the mother's age. Choice A is incorrect because Down's syndrome is caused by an extra copy of chromosome 21, not a defect in the sex chromosomes. Choice B is incorrect as the symptoms of Down's syndrome and sickle-cell anemia are different. Choice C is also incorrect as Down's syndrome is not caused by a sexually transmitted infection during conception.