noun
Only when written 卵
General biological sense for eggs of birds, insects, fish, amphibians, and similar animals. The kanji 卵 is the standard spelling for this use.
カエルが池に卵を産んだ。
A frog laid eggs in the pond.
サケの卵はイクラとして食べられる。
Salmon roe is eaten as ikura.
noun
egg; hen's egg; egg used in cooking
Everyday food sense, usually a chicken egg unless context says otherwise. 玉子 is often used in cooking and dish names, while 卵 remains broadly standard.
朝食に卵を二つ焼いた。
I fried two eggs for breakfast.
玉子をよく溶いてからフライパンに流し込む。
Beat the eggs well, then pour them into the frying pan.
noun
budding ...; ... in the making; future ...
Only when written 卵
Figurative pattern ...の卵 for a person who is still training or not yet fully established in a profession or role.
彼女は医者の卵だ。
She is a doctor in the making.
その学校には映画監督の卵が集まっている。
That school attracts budding film directors.
noun
beginning; embryonic stage; origin
Only when written 卵
Less common figurative use for something still in its earliest, undeveloped state; often feels metaphorical, like 'the seed' or 'embryo' of a future thing.
ノートには新しい企画の卵がいくつも書かれていた。
The notebook contained many embryonic ideas for new projects.