Human Growth and Development Final Exam Answers

Correct Answer: D

Rationale: Sensitivity to touch emerges early prenatally and is well-developed at birth. Newborn babies have a well-developed sense of touch, which is crucial for bonding with their caregivers and exploring their environment. This sensitivity to touch helps babies respond to comforting sensations such as gentle strokes and cuddles. Visual acuity, color vision, and depth perception are sensory capabilities that develop and mature after birth, not prenatally. While important for interacting with the environment, they are not as well-developed at birth as sensitivity to touch.

Correct Answer: A

Rationale: Men with even tiny amounts of dioxin in their bloodstream father nearly twice as many girls as boys. This is due to the impact of dioxin exposure on sperm cells, leading to a skewed ratio of female to male offspring. Choice B is incorrect as the question specifically mentions that men father more girls than boys. Choice C is incorrect as dioxin exposure does not necessarily lead to more twins and triplets. Choice D is incorrect as men with dioxin in their bloodstream father more girls, not fewer children overall.

Correct Answer: D

Rationale: Sensitivity to touch emerges early prenatally and is well-developed at birth. Newborn babies have a well-developed sense of touch, which is crucial for bonding with their caregivers and exploring their environment. This sensitivity to touch helps babies respond to comforting sensations such as gentle strokes and cuddles. Visual acuity, color vision, and depth perception are sensory capabilities that develop and mature after birth, not prenatally. While important for interacting with the environment, they are not as well-developed at birth as sensitivity to touch.

Correct Answer: C

Rationale: During the second month of pregnancy, the heart of the developing fetus begins to develop separate chambers, forming the structure necessary for a fully functioning heart. This is a significant milestone in the prenatal development process. Choices A, B, and D are incorrect because the appearance of the umbilical cord as a primitive body stalk typically occurs around week 5-6, touch sensitivity extending to most of the body is more characteristic of the end of the second trimester, and the heartbeat is usually detectable through a stethoscope around the 18th to 20th week of pregnancy, not during the second month.

Correct Answer: B

Rationale: The correct answer is B: nervous system and skin. The nervous system, which includes the brain, spinal cord, and nerves, as well as the skin, develop from the ectoderm layer of cells during prenatal development. Choice A is incorrect because muscles and skeleton develop from mesoderm. Choice C is incorrect because the circulatory system and other internal organs develop from mesoderm and endoderm. Choice D is incorrect because the digestive system, lungs, urinary tract, and glands develop from endoderm.