Do you think that cleistogamy is advantageous or disadvantageous to the plant? Why?

What is cross-pollination?

Which of the following is regarded as the advantage of self pollination?

Commelina produces flowers which are open and are similar to flowers of other species with exposed anthers and stigma are called ______.

A typical angiospermic embryo sac, at maturity, contains ________ nuclei and _______ cells.

Assertion $\left(\mathrm{A}\right)$: Cleistogamous flowers produce assured seed set in the absence of pollinators

Reason $\left(\mathrm{R}\right)$: Cleistogamy is invariably an Autogamy

Given below are two statements :
Statement I: Cleistogamous flowers are invariably autogamous
Statement II: Cleistogamy is disadvantageous as there is no chance for cross pollination
In the light of the above statements, choose the correct answer from the options given below :

Define pollination. Explain different types of self and cross pollination with suitable examples.