Final answer:
Serum alpha-fetoprotein is primarily produced by the fetal yolk sac and liver, with the liver becoming the main producer as the fetus develops.
Step-by-step explanation:
The majority of serum alpha-fetoprotein is produced by the fetal yolk sac and liver. Within the first few weeks after conception, it is primarily the yolk sac that produces alpha-fetoprotein. However, as the fetal liver develops, it becomes the primary site of fetoprotein production. This protein serves various roles including its function as a tumor marker and in prenatal screenings for chromosomal abnormalities. The dynamic role of AFP underscores its importance in understanding early fetal development and its utility as a diagnostic tool, contributing to the effective management of both developmental and pathological conditions during pregnancy.