Prenatally, malaria parasites hide at the

Correct Answer: B

Rationale: The correct answer is B: Placental bed. Malaria parasites hide in the placental bed during pregnancy to avoid detection by the immune system. This location provides a safe haven for the parasites to survive and replicate without being cleared by the mother's immune response. The placental bed offers a rich blood supply and a favorable environment for the parasites to thrive. Incorrect choices: A: Bone marrow - Malaria parasites do not typically hide in the bone marrow during pregnancy. C: Fetal circulation - Malaria parasites do not hide in the fetal circulation; they primarily reside in the placental bed. D: Uterine muscle - Malaria parasites do not hide in the uterine muscle; the placental bed is the main site of sequestration during pregnancy.

Correct Answer: A

Rationale: The correct answer is A: Always of the same sex. Monozygotic twins develop from a single fertilized egg, so they have the same genetic material, making them always the same sex. This is due to the fact that the sex of an individual is determined by the chromosomes inherited from the parents. This is a fundamental principle of genetics. Choices B, C, and D are incorrect because monozygotic twins can have different fingerprints, blood groups, and superfetation (conception that occurs during an existing pregnancy) is not common in monozygotic twins.

Correct Answer: B

Rationale: The correct answer is B (3000 ml) because polyhydramnios is defined as an excessive amount of amniotic fluid, typically exceeding 2000-2500 ml. A level of 3000 ml is commonly used as a cutoff point for clinical diagnosis. Choices A, C, and D are incorrect because they fall below the threshold typically considered diagnostic for polyhydramnios. Answer A (1500 ml) is too low, while choices C (1900 ml) and D (2500 ml) are below or at the lower end of the range typically associated with polyhydramnios. Therefore, the most appropriate threshold for diagnosing polyhydramnios is when the amount of amniotic fluid exceeds 3000 ml.

Correct Answer: A

Rationale: The correct answer is A: Footling. When a hand/foot lies alongside the presenting part, it indicates a footling presentation where the foot is presenting first. This is a type of breech presentation, where the baby's buttocks or feet come out first. A transverse presentation would mean the baby is lying sideways, and an unstable lie refers to the baby's position not being fixed. Therefore, the presence of a hand/foot alongside the presenting part specifically indicates a footling presentation, making choice A the correct answer.

Correct Answer: C

Rationale: The correct answer is C: Magnesium sulphate. In eclampsia, magnesium sulphate is the drug of choice because it helps prevent seizures by reducing neuromuscular irritability and blocking peripheral neuromuscular transmission. It also has vasodilatory effects, improving uteroplacental blood flow. Phenobarbitone (A) is not recommended due to its sedative effects. Calcium gluconate (B) is used to treat hyperkalemia, not eclampsia. Sodium bicarbonate (D) is used for metabolic acidosis, not eclampsia. In summary, magnesium sulphate is preferred for its efficacy in preventing and managing seizures in eclampsia.