Question

The function of micropyle in the mature seed is
A)The entry of pollen tube
B)The entry of fertilisation tube
C)The entry of water and air
D)All

Answer 1

The micropyle is a pore in the ovum-covering membrane through which the sperm enters. Micropyles are also found in microorganism sporozoites such as Plasmodium in the anterior part of the cell that ultimately leads to the apical cap.

Complete answer:
Micropyle plays a significant role in the germination of the seed. A narrow opening in the integuments at the terminal end of the nucleus is called a micropyle. In the first place, the pollen tube reaches the ovule to deposit the sperm for fertilization from the micropylar end. Second, at the time of germination of the seed, the micropyle helps the absorption of water and finally, the roots emerge through the micropyle during germination of the seeds. It is through the micropylar end that the pollen tube enters the ovule depositing the sperm, which will result in fertilization. The micropyle helps to absorb water at the time of germination of the seed. It is through this micropyle that the root emerges at the time of germination of the seed.

The opening of the micropyle allows the pollen to enter the ovule for fertilization. In gymnosperms (e.g., conifers), pollen is drawn into the ovule by a drop of fluid that flows out of the micropyle. Subsequently, the micropyle closes. Only a pollen tube enters the micropyle in angiosperms. The radicle of the seedling emerges through the micropyle during germination.

Hence, the correct answer is option (D)

Note: Pollen tubes in angiosperms hold two sperm cells to complete double fertilization into the egg and core cells. This finding could be used in agriculture, especially in increasing the formation of seeds without fertilization in important crops.