Correct Answer: B

Rationale: The correct answer is B: 'FALSE.' Monozygotic (MZ) twins are identical twins, not fraternal. Fraternal twins are dizygotic (DZ). The statement in the question is incorrect as MZ twins are genetically identical, while fraternal twins actually refer to dizygotic twins who develop from two separate fertilized eggs. Therefore, monozygotic twins are not known as fraternal twins, making option B the correct choice. Options A, C, and D are incorrect as they do not accurately describe the relationship between monozygotic and fraternal twins.

Correct Answer: D

Rationale: The correct answer is the Alpha-fetoprotein (AFP) assay. This blood test measures the level of AFP in a pregnant woman's blood, aiding in the detection of neural tube defects and certain chromosomal abnormalities in the fetus. Choice A, artificial insemination, is a method used to facilitate fertilization and is not related to detecting fetal abnormalities. Choice B, amniocentesis, involves collecting amniotic fluid for genetic testing, not directly measuring AFP levels. Choice C, endometriosis, is a medical condition involving abnormal tissue growth and is not a procedure for detecting fetal abnormalities. Therefore, the Alpha-fetoprotein (AFP) assay is the most appropriate option for detecting neural tube defects such as spina bifida and certain chromosomal abnormalities.

Correct Answer: C

Rationale: Sickle-cell anemia is a genetic disorder caused by inheriting two copies of a recessive gene, one from each parent. The correct answer is C. Choice A is incorrect because sickle-cell anemia is not primarily caused by a chromosomal abnormality. Choice B is incorrect as the condition is not linked to a single segment found only on the Y chromosome. Choice D is unrelated as it mentions a decrease in estrogen levels, which is not a cause of sickle-cell anemia.

Correct Answer: A

Rationale: A contraction duration of 100 seconds is too long and can indicate uterine hyperstimulation, which can lead to fetal distress and other complications. This prolonged contraction duration suggests that the uterus is not relaxing adequately between contractions, potentially compromising fetal oxygenation. Choice B, 'Four contractions in 10 minutes,' is a sign of tachysystole, which is concerning but not as immediately critical as the prolonged contraction duration. Choice C, 'Uterus is soft,' is not a reason to discontinue oxytocin; in fact, it is a normal finding. Choice D, 'Early deceleration of fetal heart rate,' while indicating fetal distress, is not a direct result of the oxytocin and may require intervention but not immediate discontinuation of the medication.

Correct Answer: A

Rationale: Artificial surfactant can be administered as an adjunct to oxygen and ventilation therapy for premature infants with respiratory distress syndrome (RDS). It helps improve respiratory compliance by aiding in the exchange of oxygen and carbon dioxide until the infant can produce enough surfactant naturally. The correct explanation to the parents would be that surfactant therapy enhances the baby's lung function by facilitating the exchange of oxygen and carbon dioxide. Choice B is incorrect because surfactant therapy does not affect sedation needs. Choice C is inaccurate as surfactant is not used to reduce episodes of periodic apnea. Choice D is incorrect as surfactant is not administered to fight respiratory tract infections; it specifically targets improving lung function in RDS.