Correct Answer: A

Rationale: The correct answer is A, Zygote. A zygote is formed when a sperm cell fertilizes an egg cell. It is the initial stage of prenatal development. Choice B, Embryo, refers to the stage of prenatal development after the zygote and before the foetus. Choice C, Foetus, is the stage of prenatal development after the embryo. Choice D, Pregnancy, is a broader term referring to the condition of having a developing baby in the uterus.

Correct Answer: A

Rationale: The correct answer is A: Malaria. Malaria is a prevalent cause of abortion in Zambia due to its impact on maternal health. Malaria infection during pregnancy can lead to severe complications, including miscarriage. Choices B, C, and D are incorrect because while Tuberculosis, HIV, and Ascariasis are significant health issues, they are not the commonest cause of abortion in Zambia as Malaria.

Correct Answer: B

Rationale: In incomplete abortions, the products of conception are retained. In a complete abortion, all the products of conception are expelled from the uterus. Threatened abortion refers to a situation where there is vaginal bleeding but the cervix remains closed, and it does not necessarily involve retention of products of conception. Mixed abortion is not a recognized medical term related to retained products of conception.

Correct Answer: A

Rationale: During pregnancy, the uterus undergoes various anatomical and physiological changes. The correct answer, Choice A, accurately describes these changes. The uterus softens in the anterior midline, becomes flexible at the uterocervical junction, experiences an increase in blood vasculature size and number, and myometrial cells hypertrophy. This softening and increased vascularity are essential for accommodating the growing fetus and facilitating delivery. Choices B, C, and D are incorrect because they do not reflect the typical changes that occur in the uterus during pregnancy. The uterus does not decrease in size, remain unchanged in size, become more rigid, or hypertrophy without the described softening and vascular changes.

Correct Answer: C

Rationale: Tubal abortion is most common when the ovum implants in the interstitial portion of the fallopian tube. This location is the narrowest part of the tube, making it more prone to obstruction or difficulty in the passage of the fertilized ovum. Choices A, B, and D are incorrect because tubal abortion is more likely to occur in the interstitial portion rather than the ampullary portion, isthmus, or infundibulum of the fallopian tube.