What is the viability period of pollen grains in members of the families $Rosaceae$,$Leguminosae$,and $Solanaceae$?

Contrivances for self-pollination are:

The long, hair-like strands that emerge from the young cob of maize are

Select the incorrect statement from the following:

Although sexual reproduction is a long-drawn,energy-intensive complex form of reproduction,many groups of organisms in Kingdom Animalia and Plantae prefer this mode of reproduction. Give at least three reasons for this.

Branched type of pollen tube is formed in