The _____ is the inner layer of the embryo from which the lungs and digestive system develop.

Correct Answer: C

Rationale: The endoderm is the correct answer. It is the innermost layer of the embryo that gives rise to organs such as the lungs, digestive system, liver, and pancreas. The neural tube (Choice A) forms the brain and spinal cord, not the lungs or digestive system. Mesoderm (Choice B) develops into structures like muscles, bones, and circulatory system, not the lungs or digestive system. The umbilical cord (Choice D) serves as a connection between the embryo and the placenta, providing nutrients and oxygen, but it is not the layer from which lungs and digestive system develop.

Correct Answer: C

Rationale: Teratogens are environmental agents, such as drugs, chemicals, or infections, that can cause harm to a developing embryo or fetus. Mutations (Choice A) refer to changes in the DNA sequence and are not environmental agents. Autosomes (Choice B) are chromosomes that are not involved in determining an individual's sex and are not environmental agents that harm the embryo or fetus. Androgens (Choice D) are a group of hormones that are more related to male sexual development and function, not environmental agents that harm the embryo or fetus.

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: A human zygote contains 22 pairs of autosomes and one pair of sex chromosomes, totaling 46 chromosomes. Therefore, the correct answer is 22. Choices A, B, and C are incorrect because they do not accurately represent the number of autosomes in a human zygote. Option A (46) represents the total number of chromosomes in a human zygote, not the number of autosomes. Option B (44) is incorrect as it does not account for the correct number of autosomes. Option C (23) is inaccurate since it represents the total number of chromosomes in a human gamete, not the number of autosomes in a zygote.

Correct Answer: A

Rationale: Neonatal complications associated with maternal hypertension are primarily due to placental insufficiency. The correct answer is A, which includes Intrauterine Growth Restriction (IUGR) and prematurity. These complications arise from inadequate blood flow to the fetus, leading to growth restriction and premature birth. Choices B, seizures, and cerebral hemorrhage are more commonly maternal complications rather than neonatal ones. Choice C, hepatic or renal dysfunction, pertains to maternal complications of hypertensive disorders in pregnancy, not neonatal issues. Choice D, placental abruption, and Disseminated Intravascular Coagulation (DIC) are conditions linked to maternal morbidity and mortality, not neonatal complications.

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: B

Rationale: The correct answer is B: 'This test will determine the adequacy of placental perfusion.' The non-stress test is used to assess fetal well-being by monitoring the fetal heart rate in response to its own movements. It helps determine if the fetus is receiving enough oxygen and nutrients through placental perfusion. Choice A is incorrect because confirming fetal lung maturity is typically determined through tests like amniocentesis, not the non-stress test. Choice C is incorrect because detecting fetal infection is not the primary purpose of a non-stress test. Choice D is incorrect because predicting maternal readiness for labor is not the purpose of the non-stress test; it focuses on fetal well-being.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Color blindness is indeed a sex-linked abnormality as it is often associated with genes on the X chromosome. Since males have only one X chromosome, they are more likely to inherit color blindness if the gene is present. This makes color blindness more common in males. Choice B (FALSE) is incorrect because color blindness is linked to the X chromosome. Choices C (Sometimes) and D (Always) are incorrect as color blindness is consistently tied to the X chromosome.

Correct Answer: C

Rationale: Nasal stuffiness is a common symptom during pregnancy due to increased blood flow and hormonal changes. This symptom is caused by the increased blood volume and hormonal changes that lead to swelling of the nasal passages. Choices A, B, and D are incorrect. Stomach emptying rate does not significantly change during pregnancy; the uterus does not double in size at 24 weeks but rather grows steadily, and nipples typically darken in color due to increased pigmentation.