What is a Monosporic embryo sac?

Meiosis in the diploid megaspore mother cell divides it into 4 megaspores (haploid). With the degeneration of three, only one functional cell contributes to the embryo sac formation. This is known as monosporic embryo sac.

Who discovered Monosporic development?

It was observed by Hofmeister first time. Polygonum type of embryo sac is most simple, most primitive and normal, type of embryo sac. It is 7 celled, 8-nucleate and monosporic embryo sac. It was discovered for the first time in Polygonum by Strasburger.

What is the structure of Monosporic embryo sac?

since only one cell is involved out of four it is called monosporic embryo sac. It divides to form a 8 nucleate and 7 celled embryo sac. the 8 cells that are present are 3 cells that is 1 egg cell and 2 synergids are present at the micropylar end. the synergids and the egg cell together form the egg aparatus.

What is Bisporic development?

Bisporic development results from failure of cytokinesis after meiosis II. As a result, the megaspore tetrad is comprised of two cells each containing two megaspore nuclei. The embryo sac develops from one of these dyad cells by two rounds of mitotic division and the other dyad cell is suppressed.

What is Monosporic and Bisporic?

There are three types of embryo sacs, monosporic, bisporic and tetrasporic. In the monosporic embryo sac, out of the four megaspores, one megaspore at the chalazal end takes part in the formation of the embryo sac. In the bisporic embryo sac, two megaspores take part in the formation of the embryo sac.

Why it is called triple fusion?

It is called triple fusion due to the presence of 3 nuclei one from the sperm nuclei and two nuclei of polar nuclei. The fusion involves the two polar nuclei and a sperm nucleus that occurs in double fertilization leads to formation of endosperm. It means the presence of 3 nuclei (3n).

What is meant by Monosporic development of female gametophyte Vedantu?

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.

Why is it called double fertilization?

This is called double fertilization because the true fertilization (fusion of a sperm with an egg) is accompanied by another fusion process (that of a sperm with the polar nuclei) that resembles fertilization. Double fertilization of this type is unique to angiosperms.

Which one of the following is an example of Monosporic type of embryo sac?

It is also called the Allium type of embryo sac. Therefore, the correct answer is option B. Note: In the tetrasporic type of embryo sac, a single megaspore is formed after meiosis which contains 4 haploid nuclei. It is also called the Peperomia type of embryo sac.

What is the fate of megaspores during female gametophyte development?

During megasporogenesis, diploid megaspore mother cells undergo meiosis and give rise to haploid megaspores, which then, during megagametogenesis, develop into haploid female gametophytes.

Which is an example of Monosporic embryo sac?

Which is a Bisporic type of embryo sac?

The bisporic embryo sac are of two types: Allium type and Endymion type. The bisporic embryo sacs are 8–nucleated and 7–celled. Allium type: The embryo sac is derived from the chalazal dyad cell . Endymion type: The embryo sac is formed by the micropylar dyad cell .