Incorrect Statement:

"α- cellulosic band are present in ephemeral layer of pollen grain"

Explanation:

The given statement is incorrect as the α-cellulosic band is not present in the ephemeral layer of the pollen grain. The α-cellulosic band is a layer of cellulose that is present in the cell wall of certain plant cells such as fibers, tracheids, vessels, and sclereids.

The ephemeral layer of the pollen grain, also known as the exine, is made up of sporopollenin, a complex organic polymer that is highly resistant to decay and degradation. The exine protects the pollen grain during its journey from the anther to the stigma of the flower.

Corrected Statement:

"The α-cellulosic band is present in the cell wall of certain plant cells such as fibers, tracheids, vessels, and sclereids, but is not present in the ephemeral layer of the pollen grain."

Explanation:

To understand the corrected statement, it is important to know the following terms:

- Cellulose: Cellulose is a complex carbohydrate that is the primary structural component of the cell wall in plants.

- Cell Wall: The cell wall is a rigid layer of material that surrounds the cell membrane of plant cells and provides support and protection.

- Ephemeral Layer: The ephemeral layer, also known as the exine, is a layer of material that makes up the outer surface of the pollen grain.

- α-Cellulosic Band: The α-cellulosic band is a layer of cellulose that is present in the cell wall of certain plant cells such as fibers, tracheids, vessels, and sclereids.

Based on the above definitions, the corrected statement can be explained as follows:

- The α-cellulosic band is a layer of cellulose that is present in the cell wall of certain plant cells, but it is not present in the ephemeral layer of the pollen grain.

- The ephemeral layer, also known as the exine, is made up of sporopollenin, a complex organic polymer that is highly resistant to decay and degradation.

- The exine protects the pollen grain during its journey from the anther to the stigma of the flower.

In conclusion, the given statement is incorrect as the α-cellulosic band is not present in the ephemeral layer of the pollen grain. The corrected statement clarifies that the α-cellulosic band is present in the cell wall of certain plant cells, but not in the ephemeral layer of the pollen grain.