Read the following statements and choose the correct option.
Statement I : Pollen tube enters the ovule through the micropyle and then enters one of the synergids through the filiform apparatus.
Statement II: Filiform apparatus present at the micropylar part of the synergids guides the entry of pollen tube.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Both the statements are correct.
After pollination, the pollen tube grows down the style and reaches the ovule. It must deliver the male gametes inside the embryo sac. The synergids lie at the micropylar end of the embryo sac. Each synergid has special cellular thickenings at its micropylar tip, called the filiform apparatus.
Statement I: Pollen tube enters the ovule through the micropyle and then enters one of the synergids through the filiform apparatus. — True. The tube enters the ovule through the micropyle. It then passes into one synergid through the filiform apparatus and releases the male gametes there.
Statement II: Filiform apparatus present at the micropylar part of the synergids guides the entry of pollen tube. — True. The filiform apparatus is the structure that guides the pollen tube into the synergid.
NCERT Extract:
Pollen-Pistil Interaction – “… Pollen tube, after reaching the ovary, enters the ovule through the micropyle and then enters one of the synergids through the filiform apparatus (Figure 1.12d, e). Many recent studies have shown that filiform apparatus present at the micropylar part of the synergids guides the entry of pollen tube.”
Figure 1.12 (d) Enlarged view of an egg apparatus showing entry of pollen tube into a synergid; (e) Discharge of male gametes into a synergid and the movements of the sperms, one into the egg and the other into the central cell