112
Prenatal Development
§
A zygote is a fertilized cell with 100 cells, which
become increasingly diverse. At about 14 days
the zygote turns into an embryo (a and b).
Lennart Nilsson/ Albert Bonniers Publishing Company
Biophoto Associates/ Photo Researchers, Inc.
OBJECTIVE 8-3
| Define
zygote
,
embryo
and
fetus
, and explain how teratogens can affect development.
