Question

Identify the correct pair of statements.
1) The filiform apparatus helps in absorption of food.
2) Antipodals are the vegetative cells of the female gametophyte.
3) The fusion of two polar nuclei and male gametes occurs always before the entry of the pollen tube.
4) The largest cell of embryonic sac is the egg cell.
The correct pair is
A) (I), (II)
B) (II), (III)
C) (I), (IV)
D) (III), (IV)

Answer 1

Hint: Plants reproduce both sexually and asexually. Sexual reproduction in plants is the process of fusion of gametes, resulting in the offspring which are genetically different from the parents. It results in the diploid zygote.

Complete Answer:
1) Filiform apparatus- It is found in angiosperm. It is a finger-like projection which consists of an enclosed core of microfibrils in a sheath. It assists the entry of pollen tubes into an ovule. It helps in food absorption. Hence the statement (I) is correct.

2) Antipodal cells- These cells are present in the mature embryo sac. They are three in number and are haploid vegetative cells. It is present in the opposite end of the micropyle. Hence statement (II) is correct.

3) Pollen tubes are formed when pollen grains fall on the stigma. The pollen tube passes through style and enters the ovule. Thus it releases two male gametes there. One male gamete fuses with the egg cell to form zygote. Whereas, the other male gamete fuses with two polar nuclei in the central cell to form a triploid endosperm nucleus. The fusion occurs after the entry in the pollen tube. Hence the statement (III) is incorrect.

4) The central cell is the largest cell of the embryonic sac. Hence statement (IV) is incorrect.

Thus the correct answer is (A).

Note: The transfer of male gametes to female gametes occurs by pollination. After pollination, fertilisation takes place and ovules grow into seed inside the fruit.