Human Growth and Development Exam Questions

Correct Answer: D

Rationale: If pregnancy does not occur, the corpus luteum will shrink. As a result, the lining of the uterus is discarded through the process of menstruation. This shedding of the uterine lining is what causes menstrual bleeding. Choices A, B, and C are incorrect because they do not describe the physiological response of the body when pregnancy does not occur. The corpus luteum shrinking and the subsequent shedding of the uterine lining are part of the menstrual cycle, not processes related to cell duplication, zygote multiplication, or the duration of the germinal period.

Correct Answer: C

Rationale: During the second trimester of pregnancy, a white, cheeselike substance called vernix emerges on the skin of the developing fetus. Vernix is a protective layer that helps prevent the skin from becoming waterlogged during the time in the amniotic fluid. Choice A, lanugo, is incorrect as lanugo refers to the fine, soft hair that covers the body of a fetus. Choice B, corpus luteum, is incorrect as it is a temporary endocrine structure involved in the menstrual cycle. Choice D, chorion, is incorrect as it is one of the membranes that surround the embryo and later the fetus.

Correct Answer: C

Rationale: The statement that is true about a blastocyst is that between the seventh and ninth days, it burrows deep into the uterine lining. This process, known as implantation, is essential for the blastocyst to establish a connection with the mother's body and receive nutrients for further development. It is a critical stage in prenatal development and sets the foundation for pregnancy. Choices A, B, and D are incorrect. A blastocyst is not a single cell but rather a structure composed of many cells. It is not a structure that feeds the developing organism; instead, it implants in the uterine lining to receive nutrients. It is not a membrane that regulates temperature but plays a crucial role in the initial stages of pregnancy by implanting in the uterus.

Correct Answer: A

Rationale: A rise in the baby's heart rate during pregnancy is usually followed within five seconds by a burst of motor activity. This indicates that the baby is responding to stimuli and is an important sign of healthy fetal development. A period of sleep, a rise in Liz's heart rate, or a drop in Liz's body temperature are not typically immediate responses to changes in the baby's heart rate. Sleep is less likely to be a direct response to changes in heart rate, Liz's heart rate is independent of the baby's heart rate changes, and a drop in Liz's body temperature is not a common immediate response to fetal heart rate changes.

Correct Answer: C

Rationale: The description of Baby Azeez's behavior matches the characteristics of irregular sleep in a newborn. During irregular sleep, limb movements are gentle, occasional facial grimacing occurs, and rapid eye movements can be seen beneath closed eyelids. This state is also known as active sleep and is associated with dreaming in newborns. Choice A, regular sleep, is incorrect as the described behaviors are not typical of this state. Choice B, drowsiness, does not match the active movements and facial grimacing observed in Azeez. Choice D, quiet alertness, is also incorrect as it does not align with the described behaviors of limb movements, facial grimacing, and rapid eye movements.