Question

Length of pollen tube depends on the distance between 

(a) pollen grain and an upper surface of the stigma 

(b) pollen grain on the upper surface of stigma and ovule 

(c) pollen grain in anther and the upper surface of the stigma 

(d) upper surface of stigma and lower part of the style

Answer 1

The answer is (d) upper surface of stigma and lower part of style

Length of pollen tube ensures pollens reach the stigma to conduct pollination.