In which plant does vegetative propagation occur through leaves?

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

Factors responsible for the rapid spread of bread mould on slices of bread are:
$(i)$ Large number of spores
$(ii)$ Availability of moisture and nutrients in bread
$(iii)$ Presence of tubular branched hyphae
$(iv)$ Formation of round shaped sporangia

Why does bread mould grow profusely on a moist slice of bread rather than on a dry slice of bread?

$(a)$ Trace the path of sperms from where they are produced in the human body to the exterior.
$(b)$ Write the functions of secretions of the prostate gland and seminal vesicles in humans.

At what age do girls typically reach puberty (in $years$)?