What term refers to the fertilized egg during the initial two weeks after fertilization?

What term refers to the fertilized egg during the initial two weeks after fertilization?

• A. Zygote
• B. Embryo
• C. Fetus
• D. Germ

Answer: (A)

The first two weeks after fertilization are defined by the zygote stage. A zygote is the single cell formed when sperm and egg fuse, and it immediately begins rapid cell divisions (cleavage) without growing in size. This stage lasts until implantation in the uterus begins and the embryo proper starts to form later on. After implantation, the developing person is typically called an embryo, and later, after about eight weeks, a fetus. The term germ isn’t used to describe this early post-fertilization stage. So, during those initial two weeks, the fertilized egg is the zygote.

The first two weeks after fertilization are defined by the zygote stage. A zygote is the single cell formed when sperm and egg fuse, and it immediately begins rapid cell divisions (cleavage) without growing in size. This stage lasts until implantation in the uterus begins and the embryo proper starts to form later on. After implantation, the developing person is typically called an embryo, and later, after about eight weeks, a fetus. The term germ isn’t used to describe this early post-fertilization stage. So, during those initial two weeks, the fertilized egg is the zygote.