Question

Filiform apparatus is a characteristic feature of _______________
A. Zygote
B. Suspensors
C. Egg
D. Synergid

Answer 1

It is a feature of embryo sac. The projection like growth which will help in the fertilization. They are an important part of the work of directing the pollen to the egg cell. They are the guiding cells.

Complete answer:
A flower has an ovary which acts as its female reproductive part. Pollen from the other flowers moves to the ovary via style and stigma to fuse from the embryo. This embryo will lead to the seed of a fruit.
Let us study the various parts of the flower.
Option A.- Zygote: The diploid cell formed after the fertilization of the pollens and the eggs form a zygote which on maturation will form an embryo.
Option B. – Suspensor: They are the group of cells released by endosperm for providing nourishment to the developing embryo.
Option C. – Egg: The female ovules are called the eggs. They are present in the ovaries of the female gametophyte. A flower has stigma, style and ovary. Stigma and style help in landing and directing the pollen whereas the ovary causes the fertilization.
Option D. – Synergid: This is one of the short-lived small nuclei near the egg in the mature embryo sac. They help the pollen to reach the egg cell. They direct a tube towards the female gametophyte to direct fertilization. The main contributor is the filiform apparatus which helps in this guiding. It is the prolongation of the synergids.

So, the answer is, option D - Synergid

Note: Synergids are haploid. They are formed by mitosis from functional megaspore. They are important for the cessation of the pollen tube and release of sperms. They degenerate after the fertilization as they are the vegetative cells of the embryo sac.