Correct Answer: C

Rationale: The correct answer is C. Mutations can occur due to environmental influences such as radiation, chemicals, or other external factors, leading to changes in the DNA sequence. Choice A is incorrect because mutations can also occur due to errors in DNA replication, not solely by chance. Choice B is incorrect as mutations affect the DNA sequence itself, not the production of specific cells. Choice D is incorrect because mutations involve changes in the DNA sequence and do not specifically involve the formation of the DNA structure.

Correct Answer: C

Rationale: Thalidomide is the correct answer. Thalidomide was a drug marketed in the 1960s to pregnant women as a sedative and anti-nausea medication but tragically led to severe birth defects, including limb deformities, when taken during pregnancy. Progestin (Choice A) and Estrogen (Choice B) are hormones that are not associated with causing birth defects like Thalidomide. Oxytocin (Choice D) is a hormone that plays a role in labor and breastfeeding and is not known to cause birth defects like Thalidomide.

Correct Answer: C

Rationale: The correct answer is C. Proteinuria, indicated by a dipstick value of 3+ in the urine, is a significant concern in a patient being monitored for preeclampsia. Proteinuria is a key diagnostic criterion for preeclampsia, and a value of 3+ signifies a substantial amount of protein in the urine, warranting further evaluation. While an increase in blood pressure to 138/86 mm Hg is slightly elevated, it does not meet the diagnostic threshold for severe hypertension in preeclampsia. A weight gain of 0.5 kg over 2 weeks is within normal limits and not as concerning as significant rapid weight gain. Pitting pedal edema, though common in pregnancy, is not a specific indicator of preeclampsia and is considered a less concerning finding compared to significant proteinuria.

Correct Answer: D

Rationale: After an amniocentesis, the nurse should monitor the client for potential complications, with hemorrhage being a significant concern due to the invasive nature of the procedure. Hyperemesis (severe vomiting), proteinuria (excessive protein in the urine), and hypoxia (low oxygen levels) are not typically associated with amniocentesis and are less likely to occur compared to hemorrhage, which is a more common complication that requires prompt recognition and intervention.

Correct Answer: B

Rationale: Preconception counseling is essential as strict metabolic control before conception and in the early weeks of gestation helps reduce the risk of congenital anomalies. Frequent episodes of maternal hypoglycemia usually occur during the first trimester due to hormonal changes, affecting insulin production and use, rather than before conception. Hydramnios is more common in diabetic pregnancies, typically seen in the third trimester, not during early pregnancy. Hyperemesis gravidarum, although it may lead to hypoglycemic events, is related to decreased food intake and glucose transfer to the fetus, exacerbating hypoglycemia rather than being directly associated with poor glycemic control before and during early pregnancy.