Embryo sac is to ovule as ____________ is to an anther.

The correct option is C

Pollen grain

The correct option is C.

Explanation of correct option:

1. The embryo sac or the female gametophyte is located inside the ovule and is formed from the functional megaspore.
2. Pollen grain represents the male gametophyte.
3. It is produced by the meiotic division of the microspore mother cell present in the pollen sacs in the anther.

Explanation of incorrect options:

Option A:

Stamen represents the male reproductive organ of the flower and consists of a filament and the anther at its tip.

Option B:

The filament is the stalk-like structure of the stamen that provides nourishment to the anther and holds the anther in a position favorable for pollination.

Option D:

Androecium represents the third whorl of a flower and consists of stamens that are the male reproductive organs of a flower.

Final answer: Embryo sac is to ovule as pollen grain is to anther.