What is the developing human organism called from about two weeks after fertilization through the end of the second month?

What is the developing human organism called from about two weeks after fertilization through the end of the second month?

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

Answer: (A)

The main idea here is prenatal development stages. About two weeks after fertilization, the developing organism is labeled an embryo, and this stage continues through the end of the second month (roughly eight weeks after fertilization). During this embryonic period, rapid growth and the formation of the major organ systems begin from the three germ layers, a process known as organogenesis. After this period, development shifts into the fetal stage, which lasts from around the ninth week until birth. The other terms refer to earlier or later stages: a zygote is the fertilized cell from fertilization up to implantation, and a blastocyst is an earlier-stage embryo around five days after fertilization.

The main idea here is prenatal development stages. About two weeks after fertilization, the developing organism is labeled an embryo, and this stage continues through the end of the second month (roughly eight weeks after fertilization). During this embryonic period, rapid growth and the formation of the major organ systems begin from the three germ layers, a process known as organogenesis. After this period, development shifts into the fetal stage, which lasts from around the ninth week until birth. The other terms refer to earlier or later stages: a zygote is the fertilized cell from fertilization up to implantation, and a blastocyst is an earlier-stage embryo around five days after fertilization.