Members of which plant family,pollen grains maintain viability for months?

Cleistogamous flowers are found in:

In the figure given below,label the following parts: male gametes,egg cell,polar nuclei,synergid,and pollen tube.

Which of the following statements is incorrect?

The number of meiotic divisions required to produce $40$ seeds in $Capsella$ is:

Study the following statements.
$I$. Pollen grains of many species cause severe allergies and bronchial afflictions in some people,often leading to chronic respiratory disorders.
$II$. Pollen grains are rich in nutrients.
$III$. Carrot grass came into India as a contaminant with imported wheat.