question

where does megasporogenesis occur in the ovule of an angiosperm ? describe the process up to the development of a mature embryo sac.

 

 

 

 

 

 

occurs in the nucellus (towards the micropylar end)

a single megaspore mother cell mmc) undergoes meiotic division, results in the generation of four megaspores, one of the megaspores is functional while the other three degenerate, this type of megasporogenesis ismonosporic andthe nucleus of the functional megaspore separates mitotically to form the 8-nucleate stages of the embryo sac. six of the eight nuclei are enclosed by cell walls, the remaining two polar nuclei remain in the large central cell, the three cells are towards the micropylar end are the two synergids and one egg cell, three cells at the chalazal end are called the antipodals.

a typical angiosperm embryo sac at maturity is 8-nucleate and 7-celled.