卵
たまご · tamago · JLPT N5 · noun
egg
🥚 tamago = tama (ball, 玉) + ko (child, 子): a ball-child
Tamago comes from tama (ball, jewel) plus ko (child), with ko voiced to go. An egg is a round thing that holds a baby. The same word is also written 玉子, especially for cooked eggs, which spells the two parts out directly.
卵 — pictograph of fish/reptile eggs with yolk dots
卵 is a pictograph originally depicting a pair of eggs, with the two small strokes inside representing the yolks or embryos. The ancient seal form clearly shows two oval shapes side by side. It has consistently meant 'egg' from oracle bone times to the present.