Question

Length of pollen tube depends on the distance between

• A. pollen grain and the upper surface of the stigma
• B. pollen grain on the upper surface of stigma and ovule
• C. pollen grain in anther and upper surface of stigma
• D. upper surface of stigma and lower part of style

Answer 1

The correct option is B

pollen grain on the upper surface of stigma and ovule

The correct option is B.

Explanation for correct option:

1. The pollen tube's job is to transport male gametes to the ovary via the stigma and style.
2. It enters the ovule via the micropylar end and travels to the synergid cell close to the egg cell.
3. The pollen tube is guided into synergies by the filiform apparatus.
4. The male gamete is carried from the stigma to the ovules by the pollen tube, which is a long tube-like structure.
5. Length of pollen tube depends upon distance of pollen on stigma and ovule because after pollination pollen germinates and form pollen tube that reaches upto ovule in ovary and release male gamete to fuse with female gamete.

Final answer: Length of pollen tube depends on the distance between pollen grain on the upper surface of stigma and ovule.