Final answer:
The most accurate statement about fetal development is that the cardiovascular system is the first organ system to function in the developing human, with the heart starting to beat at around 3 weeks after fertilization.
Step-by-step explanation:
The most accurate statement regarding the development of systems and organs in a fetus is: a. The cardiovascular system is the first organ system to function in the developing human.
During the first trimester of fetal development, the human heart is the first functional organ to develop. It starts beating and pumping blood around day 21 or 22 after fertilization. The critical role of the cardiovascular system at this stage is underscored by its function of distributing blood throughout the fetus, which is important for the exchange of nutrients, oxygen, and wastes with the developing baby.
Hematopoiesis, the process of erythrocyte production, initially occurs in the yolk sac, and then the liver takes over this role during the embryonic period before the bone marrow begins to assume this task later in development, typically around weeks 9-12.
The fetus undergoes significant structural and functional changes during the gestational period, such as the body elongating, the ossification of the skeleton, and the beginnings of erythrocyte production moving to the bone marrow. The statement regarding the gastrointestinal system maturing by 32 weeks of gestation does not accurately reflect that some parts of the gastrointestinal system continue to develop and mature after birth.