One of the following occurs in the reproductive system of flowering plants as well as that of humans. This is :

In human females, an event that indicates the onset of reproductive phase is :

The off springs formed as a result of sexual reproduction exhibit more variations because :

Which among the following statements are true for unisexual flowers?

(i) They possess both stamen and pistil

(ii) They possess either stamen or pistil

(iii) They exhibit cross pollination

(iv) Unisexual flowers possessing only stamens cannot produce fruits

Which of the following statements are true for sexual reproduction in flowering plants?

(i) it requires two types of gametes

(il) fertilisation is a compulsory event

(iii) it always results in the formation of zygote

(iv) offsprings formed are clones