During the period of the embryo, the __________ becomes the __________.

Correct Answer: D

Rationale: During the period of the embryo, the endoderm becomes the digestive system, lungs, urinary tract, and glands. The endoderm is one of the primary germ layers that give rise to various internal organs in the developing embryo. It plays a crucial role in the formation of organs such as the digestive system, respiratory system, and glandular structures.

Correct Answer: A

Rationale: In pharmacology, understanding fetal development is crucial as it impacts drug effects on both mother and fetus. In this scenario, the correct answer is A) a 20-week-old fetus can be stimulated as well as irritated by sounds. At this stage, the fetus's auditory system is developing, allowing it to perceive sounds. This is supported by research showing fetal responses to external stimuli like music or voices. Option B) is incorrect because fetal viability outside the womb typically begins around 24 weeks, so a 20-week-old fetus would not survive if born prematurely. Option C) is incorrect as premature infants often require oxygen support to breathe due to underdeveloped lungs. Option D) is incorrect as fetal thermoregulation is not fully developed at 20 weeks, so the fetus cannot control its body temperature. Educationally, this question highlights the importance of understanding fetal development milestones for healthcare providers prescribing medications to pregnant women. It underscores the need to consider the impact of external stimuli on fetal well-being and the limitations of fetal viability and physiological functions at different gestational ages.

Correct Answer: D

Rationale: High doses of caffeine contained in coffee and tea have been linked to an increased risk of low birth weight. Consuming large amounts of caffeine during pregnancy can interfere with the baby's growth and development, leading to a lower birth weight than expected. It is important for pregnant women to limit their caffeine intake to reduce the risk of complications such as low birth weight.

Correct Answer: B

Rationale: Newborns of smoking mothers display more muscle tension. This is because nicotine in cigarettes can lead to increased muscle tension in babies, which can affect their physical development and potentially lead to future health issues. This is one of the negative effects of smoking during pregnancy on the developing fetus.

Correct Answer: C

Rationale: In pharmacology, understanding the impact of maternal alcohol consumption on fetal development is crucial. Fetal alcohol syndrome (FAS) is a serious concern that can result from maternal alcohol use during pregnancy. In this scenario, the expectant mother with the greatest risk of having a baby born with FAS is Yvonne, a Native American. Yvonne, as a Native American, has a higher risk due to genetic factors that can influence alcohol metabolism differently compared to other ethnicities. Native Americans tend to have a higher prevalence of alcohol use disorder, which can increase the likelihood of excessive alcohol consumption during pregnancy, leading to a higher risk of FAS in their babies. Conversely, the other options (Caucasian American, African American, and Asian American) do not have the same genetic predisposition or cultural factors that may contribute to increased alcohol consumption during pregnancy, thus lowering their risk compared to Native Americans. This educational context highlights the intersection of genetics, cultural factors, and pharmacological effects on fetal development, emphasizing the importance of considering individual risk factors in maternal healthcare and the prevention of FAS. Understanding these nuances is critical for healthcare providers to deliver targeted interventions and support to at-risk populations.