Where does the male produce sperm, and where are these glands located?

Correct Answer: D

Rationale: The male produces sperm in the testes, which are two glands located in the scrotum. The scrotum is the external sac that houses and protects the testes, allowing for optimal temperature regulation to support sperm production. Choice A is incorrect because sperm production does not occur in the penis. Choice B is incorrect because the scrotum houses the testes, not the penis. Choice C is incorrect because sperm is produced in the testes, not the penis.

Correct Answer: C

Rationale: The correct answer is C: embryo. The most rapid prenatal changes occur during the embryo stage, which spans from approximately 2 to 8 weeks after conception. This period is crucial as major organs and systems of the body develop rapidly, laying the foundation for future growth and development. The zygote stage is the initial single-celled entity formed by the union of sperm and egg, while the blastocyst stage involves the cluster of cells resulting from the zygote dividing and growing. The fetus stage follows the embryo stage and focuses on refining and growing existing structures rather than rapid development. Therefore, the embryo stage is where the most significant and rapid changes take place in prenatal development.

Correct Answer: B

Rationale: By the end of Greta's first month of pregnancy, her embryo is about ¼ inch long. During the first month of pregnancy, the embryo is in the very early stages of development, and its size is typically around ¼ inch as it continues to grow and develop in the uterus. Choices A, C, and D are incorrect because sensory abilities like sensing the world, sucking thumb, and curling toes develop later in the pregnancy as the embryo progresses through different stages of development.

Correct Answer: D

Rationale: Lanugo helps the vernix stick to the skin. Vernix is a waxy substance that covers the fetus's skin during pregnancy. Lanugo is a fine, downy hair that helps to anchor the vernix to the skin, providing protection and nourishment to the developing fetus. Choices A, B, and C are incorrect as they do not accurately describe the role of lanugo in prenatal development.

Correct Answer: D

Rationale: In the eighth month of pregnancy, lanugo typically is shed. Lanugo is the fine, downy hair that covers a fetus's body to help regulate body temperature while in the womb. By the eighth month, many fetuses shed this hair as they prepare for birth. Choices A, B, and C are incorrect because fetal growth doubling, neuron production increasing, and the formation of eyes, ears, nose, jaw, and neck occur in earlier stages of pregnancy, not specifically in the eighth month.