Question

A flower of tomato plant following the process of sexual reproduction produce 240 viable seeds.

Answer the following questions giving reasons:

(i) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil?

(ii) What would have been the minimum number of ovules present in the ovary?

(iii) How many megaspore mother cells were involved?

(iv) What is the minimum number of microspore mother cells involved in the above case?

(v) How many male gametes were involved in this case?

Answer 1

(i) 240 pollen grains. One pollen grain participates in fertilisation of one ovule.

(ii) 240 ovules. One ovule after fertilisation forms one seed

(iii) 240 MMC were involved. Each MMC forms four megaspores out of which only one remains functional.

(iv) 60 MMCs (240/4 = 60). Each microspore mother cell meiotically divides to form four pollen grains.

(v) 480 male gametes (240 × 2 = 480). Each pollen grain carries two male gametes (which participate in double fertilisation)