Differentiate between male and female heterogamety.

Double fertilization is reported in plants of both, castor and groundnut. However, the mature seeds of groundnut are non-albuminous and castor are albuminous. Explain the Post fertilization events that are responsible for it.

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

Answer the following questions giving reasons:

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

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

(c) How many megaspore mother cells were involved?

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

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

An anther with malfunctioning tapetum often fails to produce viable male gametophytes. Give any one reason.

Geitonogamous flowering plants are genetically autogamous but functionally cross-pollinated. Justify.

(a) State the difference between meiocyte and gamete with respect to chromosome number.

Name the type of cell division that takes place in the zygote of an organism exhibiting haplontic life cycle.

Why do moss plants produce very large number of male gametes? Provide one reason. What are these gametes called?

Explain the significance of meiocytes in a diploid organism.

90.

Name the phase all organisms have to pass through before they can reproduce sexually.