Human Growth and Development Exam Questions

Correct Answer: B

Rationale: The force of blood flowing through the umbilical cord keeps it firm. The umbilical cord is the connection between the placenta and the fetus, providing essential nutrients and oxygen to the developing baby. Blood flow through the umbilical cord helps maintain its structure and function throughout the prenatal period. Choices A, C, and D are incorrect as they do not play a role in providing nutrients and oxygen to the developing baby or in maintaining its firmness.

Correct Answer: C

Rationale: To avoid exposure to toxoplasmosis, Kaye should ask other family members to change the litter box. Toxoplasmosis is a parasitic infection that can be transmitted through cat feces, so it is important for pregnant women to avoid handling cat litter to reduce the risk of infection. Choices A, B, and D are incorrect because they are not directly related to preventing toxoplasmosis. Smoking cessation is important for overall health but not specifically to prevent toxoplasmosis. Picking up after the dog and feeding the fish are not relevant to preventing toxoplasmosis, as the infection is primarily associated with cat feces.

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: B

Rationale: The correct answer is B: eye-blink. The eye-blink reflex is the one that protects an infant from strong stimulation by causing them to quickly shut their eyes in response to sudden bright light or a loud noise. This reflex helps to safeguard the infant's sensitive eyes from potential harm. The Moro reflex (choice A) is the startle reflex, the sucking reflex (choice C) helps with feeding, and the palmar grasp reflex (choice D) is when the infant's fingers close around an object placed in their hand; none of these reflexes specifically protect the infant from strong stimulation.

Correct Answer: D

Rationale: In ecological systems theory, the chronosystem refers to the dimension of time and how events and transitions over time can influence an individual's development. Toby's move just before entering fourth grade represents a significant change in his life that falls under the chronosystem. The microsystem involves the immediate environments and relationships that directly influence an individual, the mesosystem relates to connections between these environments, and the exosystem includes external settings that indirectly influence the individual, such as parents' workplaces. Therefore, Toby's move best exemplifies a change in the chronosystem due to the temporal influence on his development.