Female gametophyte

This slide shows the information about gameophyte.
there are two type of gametophyte
1) male gameetophyte
2)female gametophyte
we only discussed about the female gametophyte. it has megagametogenesis and different kind of embryo secs and their discription are also their in the slide.

1. Female gametophyte Mansi prajapati Gayatri thakurathi

2. what are the gametophytes A  gametophyte  is a stage in the life cycle of plants and algae that undergo alternation of generations. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sexual phase in the life cycle of plants and algae. It develops sex organs that produce gametes, haploid sex cells that participate in fertilization to form a diploid zygote in which each cell has two sets of chromosomes. Cell division of the zygote results in a new diploid multicellular organism, the second stage in the life cycle known as the sporophyte, the function of which is to produce haploid spores by meiosis .

3. Female gametophyte The female gametophyte is also called the embryo sac. In angiosperms it mostly develops as a seven celled, eight-nucleate structure. It consists of three antipodal cells, one central cell, two synergid cells, and one egg cell mostly. It generally contain antipodal cells at chalazal ends, an egg cell and two synergids at microplyar ends, and a center containing two polar nuclei. Embryo sec is expect the center binucleate cell .

4. megagametogenesis Megagametogenesis  is the development of a megaspore into an embryo sac, though a highly reduced one - stage in the life cycle of vascular plants. Megagametogenesis involves three identifiable events: 1. A series of mitoses without cytokinesis, 2. Cellularization of the nuclei 3. Cell differentiation

5. Types of embryo sac There are three type of megasporogenesis; respectively, Monosporic embryo sac : develop from single megaspore and it sub divided into two type; polygonum type, oenothera type. Bisporic embryo sac : the mmc divide to form dyad cell. there is only one dyad cell undergoes meiotic division and other degenerates. Further its sub divided into 2 types of embryo sac; allium type and endymion type. Tetrasporic embryo sac : mmc divide to form four haploid nuclie. All the four nuclei takes part in the formation of embryo sac. Its further devided into no nuclear fusion and nuclear fusion.

6. Types of tetrasporic embryo sac Mega spore nuclear fusion not occur Adoxa type Plumbago type Penaea type Peperomia type Dursa type Megaspore nuclei fuse to form triploid Fritillaria type Plumbagella type Chrysanthimum type

7. Embryo sac development in angiosperm Arabidopsis thaliana

8. Mature gametophyte

9. Structure of the mature female gametophyte

10. Thank you