Why is the lining of the stomach covered with rugae?

Correct Answer: B

Rationale: Rugae are folds in the stomach lining that increase its surface area. This increased surface area allows for more efficient digestion and absorption of nutrients in the stomach. Choice A is incorrect because rugae do not directly affect the output of gastric juices. Choice C is incorrect because rugae do not impact the permeability of the stomach walls. Choice D is incorrect because rugae do not influence the types of nutrients that can diffuse.

Correct Answer: D

Rationale: The cervix is located at the bottom of the uterus, where it opens into the vagina. It serves as the passageway between the uterus and the vagina, playing a crucial role in childbirth and menstrual flow. Choice A ('Top of the uterus') is incorrect because the cervix is not located at the top of the uterus. Choice B ('Top of the ovaries') is incorrect as the cervix is not located near the ovaries. Choice C ('Bottom of the vagina') is incorrect as the cervix is not located at the bottom of the vagina, but rather at the bottom of the uterus.

Correct Answer: A

Rationale: The correct answer is A: Embryogenesis. The first trimester of gestation involves the process of embryogenesis, where the basic structures of the embryo are formed. This period is critical for the development of major organ systems and the establishment of the embryo's overall body plan. Fertilization occurs at the beginning of pregnancy when the sperm fertilizes the egg, marking the start of embryonic development. Meiosis is a cell division process that produces gametes (sperm and egg cells) with half the number of chromosomes. Menstruation is the shedding of the uterine lining when pregnancy does not occur.

Correct Answer: C

Rationale: Metabolic wastes produced by the developing fetus are eliminated primarily by being passed down the umbilical cord to the mother's circulatory system. Once in the mother's blood, these wastes are then filtered and excreted by the mother's kidneys. Choice A is incorrect because the developing fetus does produce metabolic wastes. Choice B is incorrect as fetal waste does not pass into the mother's anus. Choice D is incorrect as fetal waste does not leave the mother's body via the vagina.

Correct Answer: A

Rationale: The correct route of a fetus during childbirth is from the uterus, through the cervix, and then out through the vagina. The contractions of the uterus help push the fetus through the cervix and out through the vaginal canal during childbirth. Choice B is incorrect as it reverses the order of the cervix and uterus. Choice C is incorrect as it includes the vas deferens, which is not part of the female reproductive system. Choice D is incorrect as it lists structures from the female reproductive system but in the wrong order for childbirth.