What is tetrasporic Embryosac?

All the four nuclei of coeno-megaspore participate in the formation of the embryo sac. This type of embryo sac is called as tetrasporic like in Peperomia. The four haploid nuclei of coeno-megaspore undergo two successive mitotic divisions forming 16 nuclei.

What is Monosporic Embryosac?

The formation of the female gametophyte from a single functional megaspore is called as monosporic development. The nucleus of functional megaspore divides mitotically to form two nuclei which move to opposite poles. This forms a two-nucleate embryo sac.

What is Monosporic?

When the female gametophyte (embryo sac) develops from a single megaspore, it is called monosporic development. Usually, in most angiosperms, the megaspore mother cell divides by meiosis to form four haploid megaspores arranged in a linear fashion.

Why is embryo sac called Monosporic?

Generally, there is only one embryo sac present in each ovule. The megaspore mother cell divides by meiotic division to give rise to 4 haploid megaspores. Generally, only one megaspore is functional and develops into the female gametophyte or the embryo sac. This is known as monosporic development.

Why do we call embryo sac Monosporic?

Single functional megaspore forms female gametophyte so we can call embryo sac as monosporic.

Which is an example of Bisporic type of embryo sac?

It is called the bisporic development because instead of four, two megaspores are produced as a result of meiosis in the megaspore mother cell. Each megaspore has two haploid nuclei. It is also called the Allium type of embryo sac.

Why is Embryosac called Monosporic development?

What is Monosporic development of embryo sac formation?

The development of the female gametophyte is considered monosporic growth from a single functional megaspore. The functional megaspore nucleus breaks mitotically to form two nuclei that shift to opposite poles. A two-nucleate embryo sac forms this.

What is the difference between bisporic and tetrasporic embryo sacs?

Bisporic embryo sacs contain nuclei derived from two members of a megaspore tetrad whereas tetrasporic embryo sacs contain nuclei derived from all four members of a tetrad. Megaspores from the same tetrad are less genetically similar than are megaspores from different tetrads.

What is the difference between monosporic and bisporic development?

Both phenomena have evolved multiple times. In contrast, all nuclei of monosporic female gametophytes are genetically identical. Consequently, monosporic development is predicted to be more evolutionarily stable than bisporic or tetrasporic development.

What is meant by monosporic embryosac?

(more)Loading…. Monosporic embryosac- it is also known as polygonum type embryo sac process of diploid megaspore mother cell in the nucellus produces 4 haploid mega Spores 3 of the Mega spores usually those at the micropile the end of the nucellus subsequently undergo programmed cell death leaving only one functional megaspore.

What is the difference between monosporic and tetrasporic cells?

When all degenerate only one functional cell contribute to embryo sac formation it is called monosporic. When 2 bispori,c when all 4 tetrasporic. If one mega spore mother cell undergoes division and produces 4, out of which 3 degenerates and only forms as embryosac.