Filiform apparatus is characteristic feature of

Question

Accepted Answer

The correct option is 4:
The filiform apparatus is a specialized thickening of the cell wall that projects into the synergid cytoplasm at the micropylar end of the ovule. Its primary role is to guide the pollen tube towards the egg cell within the embryo sac. The synergids are two cells located adjacent to the egg cell, and they play a crucial role in the attraction and entry of the pollen tube. The filiform apparatus is rich in pectin and hemicellulose and helps in the absorption and transport of nutrients to the embryo sac. It essentially acts as a chemical guide, secreting substances that attract the pollen tube, ensuring that fertilization occurs efficiently.

The incorrect option is 1: Generative cell. The generative cell is part of the pollen grain and divides to form two male gametes. It is involved in fertilization but does not possess a filiform apparatus.
The incorrect option is 2: Nucellar embryo. A nucellar embryo is an adventitious embryo that develops directly from the nucellar cells of the ovule, bypassing sexual reproduction. It is not a structure that would contain a filiform apparatus.
The incorrect option is 3: Aleurone cell. Aleurone cells form the outermost layer of the endosperm in many seeds, particularly cereals. Their main function is to secrete digestive enzymes during seed germination to break down stored food. They are not associated with the filiform apparatus.