uring which period of prenatal development would exposure to teratogens most likely cause defects to major body structures? a. embryo b. implantation c. fetus d. zygote

The answer is option a. embryo

Explanation:

There are three stages in the prenatal period, namely the germinal, embryonic and foetal period.

The germinal period begins at conception and last for two weeks.

The embryonic period begins after germinal stage and last for two months. It is a period where organogenesis and development of limb buds occurs. These makes it a delicate period during prenatal development.

In the fetal period, sex organs bones and muscle tissues form. There is rapid growth of the foetus. It is a period which begin after two months of conception until birth.