Production of distinct microspores and megaspores that give rise to male and female gametophytes. Retention of developmental stages within spore walls changes protection and provisioning without itself removing the need for water-dependent sperm movement in heterosporous ferns.
A megaspore is the spore type that develops into a female gametophyte in a heterosporous life cycle. It is distinct from an ovum: the megaspore begins a developmental generation, whereas an ovum is a gamete that fuses during fertilization.
The corresponding male-producing spore is a microspore. Following both spore types helps connect heterospory to the strongly reduced gametophytes of seed plants.
The spore type developing into a male gametophyte. Its production is distinct from the later production of sperm.
Articles by others on the same topic
There are currently no matching articles.