Correct Answer: B

Rationale: Individuals with cystic fibrosis have a genetic disorder that causes mucus to be thick and sticky, leading to blockages in the lungs and digestive system. This mucus buildup makes them more susceptible to severe respiratory infections, which can ultimately result in premature death in their 20s. Tay-Sachs disease (Choice A) is a genetic disorder that affects the nervous system, not typically causing respiratory infections. Turner syndrome (Choice C) and Klinefelter syndrome (Choice D) are chromosomal disorders that do not directly lead to the respiratory issues observed in cystic fibrosis.

Correct Answer: A

Rationale: At 14 weeks of gestation, the uterus is still relatively low in the abdomen. Placing the Doppler midline 2 to 3 cm above the symphysis pubis is appropriate for assessing the fetal heart rate. This location allows for better detection of the fetal heart tones as the uterus is at a lower position during this stage of pregnancy. Placing the Doppler on the left upper abdomen would not be ideal at 14 weeks gestation as the uterus is not yet at that level. Placing it two fingerbreadths above the umbilicus or lateral at the xiphoid process would also not be accurate for locating the fetal heart rate at this stage of gestation.

Correct Answer: B

Rationale: Betamethasone is a corticosteroid given to stimulate fetal lung maturity and reduce the risk of respiratory distress syndrome in preterm infants. Ampicillin (Choice A) is an antibiotic and does not prevent respiratory distress syndrome. Terbutaline (Choice C) is a tocolytic used to inhibit contractions and does not directly prevent respiratory distress syndrome. Butorphanol tartrate (Choice D) is an opioid analgesic and does not have a role in preventing respiratory distress syndrome in preterm infants.

Correct Answer: C

Rationale: Preeclampsia is a serious pregnancy complication characterized by high blood pressure that typically occurs in the second half of pregnancy. If left untreated, it can lead to severe complications for both the mother and the baby. Rubella (choice A) is a viral infection that can harm the developing fetus but is not directly related to high blood pressure in pregnancy. Syphilis (choice B) is a sexually transmitted infection that can affect pregnancy but does not specifically cause high blood pressure. Phenylketonuria (choice D) is a genetic disorder that affects metabolism and is not associated with high blood pressure in pregnancy.

Correct Answer: A

Rationale: The correct answer is 'allele.' An allele refers to one of two or more versions of a gene located at the same position on a chromosome. In genetics, alleles are responsible for variations in inherited traits. Choice B, 'zygote,' is incorrect as a zygote is a fertilized egg cell formed by the fusion of two gametes. Choice C, 'autosome,' is incorrect as autosomes are non-sex chromosomes that determine an individual's genetic traits excluding sex-linked characteristics. Choice D, 'node,' is incorrect as it does not relate to the concept of genes or genetic inheritance.