Question

Pollen tube usually enters the embryo sac _________________.

• A. Through one of the synergids
• B. Directly penetrates the egg
• C. Between one synergid and central cell
• D. By knocking of antipodal cells

Answer 1

The correct option is A Through one of the synergids

Synergids attract the pollen tube by secreting some chemotactic substances and guide the pollen tube entry. Synergids are ephemeral i.e. short-lived structures. In embryo sacs, which have two synergids, one synergid degenerates before the entry of pollen tube. This degenerated synergid provides the way for pollen tube entry in the embryo sac. The pollen tube discharges its content in the degenerated synergid. The other synergid which is the persistent synergid degenerates shortly after the pollen tube has released its contents in the embryo sac.

Hence, pollen tube enters the embryo sac through one of the synergids.

So, the correct answer is A.