Question

What is the function of the filiform apparatus at the entrance into ovule?
A) Guides pollen tubes from synergid to egg
B) Helps in the entry of pollen tube into a synergid
C) Prevents entry of more than one pollen tube into a synergid
D) Brings about opening of the pollen tube

Answer 1

Hint: The synergid cell wall forms a thick structure at the micropylar end. They are called the filiform apparatus. Filiform structure bears several fingers-like projections.

Complete Answer:
- In flowering plants, Synergids and Antipodal cells are present in the female embryo sac. Synergids are present at the micropylar end and have a cellular thickening at the tip.
- This thickening is called the filiform apparatus.
- These are two in number and along with one egg forms the egg apparatus.

Function of filiform apparatus:
- It helps in the entry of pollen tubes in synergids.
- It helps in transport of metabolites at short distances.

Thus the correct answer is B, Filiform apparatus helps in the entry of pollen tubes into a synergid.

Additional Information: The egg apparatus degenerates after the endospore nucleus is formed. Antipodal cells nourish the embryo sac. It produces substances like lipids, starch which helps in growth and development of endosperm.

Note: Filiform apparatus are the finger like projection which guides the entry of pollen tube and helps in the release of sperms. It also helps in absorption and conduction of food materials from nucellus to the embryo sac.