Filiform apparatus is the characteristic feature of which of the following options?

The correct option is A

synergids

The correct option is A

Explanation for the correct option:

1. Synergid is a part of the egg apparatus found near the micropylar end of the embryo sac.
2. The egg cell in the center is flanked by two synergids.
3. Filiform apparatus is a type of cellular thickening that is seen in synergids that lead to pollen tubes.

Explanation for the incorrect options:

Option B:

1. Aleurone is a protein present in mature seeds and tubers' protein granules.
2. Aleurone cells produce and secrete a variety of hydrolytic enzymes that break down endosperm components and provide nutrition to the developing barley embryo.

Option C:

1. The nucellar embryo is a sort of apomixis in which nucellar embryos are generated from the ovule's nucellus tissue without the need for meiosis or sexual reproduction.
2. It is basically a type of seed reproduction found in a variety of plant species, including citrus fruits.

Option D:

1. A reproductive cell is a type of cell found in pollen grains that are involved in the generation of sperm.
2. These cells are smaller as compared to vegetative cells

Final answer: Filiform apparatus is the characteristic feature of synergids.