rudimentary plant in the seed before it starts a period of rapid growth.
Embryo | |
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A human embryo, seven weeks old or nine weeks' gestational age | |
Identifiers | |
MeSH | D004622 |
TE | E1.0.2.6.4.0.8 |
FMA | 69068 |
Anatomical terminology |
An embryo is an early stage of development of a multicellular diploid eukaryotic organism. In general, in organisms that reproduce sexually, an embryo develops from a zygote, the single cell resulting from the fertilization of the female egg cell by the male sperm cell. The zygote possesses half the DNA from each of its two parents. In plants, animals, and some protists, the zygote will begin to divide by mitosis to produce a multicellular organism. The result of this process is an embryo.
In human pregnancy, a developing fetus is considered as an embryo until the ninth week, fertilization age, or eleventh-week gestational age. After this time the embryo is referred to as a fetus.