How Tapetum Cell Could Become Bi-nucleate?

Tapetum cells are the innermost layer of the anther in flowering plants, which play a crucial role in the development of pollen. They are known to undergo unique changes during the process of pollen development, including becoming bi-nucleate. Here are some ways in which Tapetum cells could become bi-nucleate:

1. Mitosis and Cytokinesis
During the early stages of Tapetum cell development, mitosis occurs, leading to the formation of two identical daughter cells. These cells then undergo cytokinesis, resulting in the formation of two distinct Tapetum cells. In some cases, the cytokinesis process can be incomplete, leading to the formation of bi-nucleate Tapetum cells.

2. Endomitosis
Endomitosis is a type of cell division that occurs without cytokinesis. In this process, the chromosomes replicate, but the cell does not divide into two separate cells. Instead, the cell becomes polyploid, with multiple sets of chromosomes. This can lead to the formation of bi-nucleate Tapetum cells.

3. Nuclear Fusion
Nuclear fusion is the process by which two nuclei combine to form a single nucleus. This process can occur in Tapetum cells, leading to the formation of bi-nucleate cells. In some cases, the fusion of two daughter nuclei can occur during mitosis, resulting in the formation of a bi-nucleate cell.

4. Programmed Cell Death
During the process of pollen development, Tapetum cells undergo programmed cell death, also known as apoptosis. As the cell begins to break down, the nucleus may fragment into two or more pieces, resulting in the formation of bi-nucleate cells.

In conclusion, Tapetum cells can become bi-nucleate through a variety of mechanisms, including mitosis and cytokinesis, endomitosis, nuclear fusion, and programmed cell death. These processes are essential for the development of healthy pollen in flowering plants.

The cells are usually bigger and normally have more than one nucleus per cell. As the sporogenous cells undergo mitosis, the nuclei of tapetal cells also divide. Sometimes, this mitosis is not normal due to which many cells of mature tapetum become multinucleate. Sometimes polyploidy and polyteny can also be seen.