Megasporogenesis
This is the formation of megaspore through integuments ovule. Below the epidermis layer of the ovule, some cell continues to grow, out of this cell one cell enlarge known as Archesporial Cell or megaspore mother cell. This Archesporial cell meiotically divides to form four haploid megaspore cells, arranged in a linear fashion.
Before this I want to familiarize you with Ovule Structure, this makes a further understanding of the process easy for you.
Ovule Structure - The typical ovule is originated from the placenta of the ovary which is small in structure and attached to the placenta by a stalk-like structure Funicle. The area where the funicle and ovule fuses are known as Hilum. On the outer side, two protective layers are present having a function to provide protection of the ovule, outer integument, and inner integument.
There is one opening present at the region where inner integument arches over the nucellus known as the Micropyler region. On the opposite side we can see there is a fusion of outer integument and funiculus, this is the Chalazal End of the ovule.
The nucellus is the mass of the cell present inside inner integuments. The nucellus provides food material to the embryo sac which is present under nucellus.
No comments:
Post a Comment