The ovum and sperm fertilize to form an embryo.
ovum; egg cell
ovary
egg yolk
fertilized egg; zygote
ovulation
hen's egg; chicken egg
egg white; albumen
ovarian follicle
eggshell
incubation; brooding
egg collection; egg harvesting · oocyte retrieval; egg retrieval
oviparity; egg-laying; produced from eggs
incubation; hatching
brooding
whole egg; egg white and yolk together
oval
cleavage; segmentation
egg sac; egg case; ootheca
egg mass; egg sack
oval tombstone; egg-shaped gravestone
oval shape; egg shape
egg mixture; egg wash
egg-shaped; ovoid
The kanji 卵 is used for both 'egg' (たまご) and 'ovum' (らん). The reading らん is the on'yomi and is used in technical and compound terms.