Question

Due to which of the following reasons the pollen tube usually grows down towards the egg?

Options

• Pollen tube has no other passage to follow.

• The filiform apparatus of synergids is believed to attract the pollen tube.  

• The egg cell attracts the pollen tube as they have dissimilar electric charge.

• Pollen tube grows under control of nucleus.

Answer 1

The filiform apparatus of synergids is believed to attract the pollen tube.

Explanation:

Synergids' filiform apparatus secretes chemotropically active chemicals that drive pollen tube toward ovule micropyle during porogamy.