An<unk>  (plural oogonia) is an immature ovum. It is a female gametogonium. They are formed in large numbers by mitosis early in fetal life from primordial germ cells, which are present in the fetus between weeks 4 and 8.
Oogonia are present in the fetus between weeks 5 and 30.
Oogonia are also the female reproductive structures in certain thallophytes, and are usually rounded cells or sacs containing one or more oospheres.
Oogonium
Meldonium
Benzethonium chloride
Isavuconazonium
Edrophonium
Benzalkonium chloride
Suxamethonium chloride
Epichlorohydrin