When the $F_1$ generation offspring is crossed with a dominant homozygous parent,what is it called?

Given below are two statements:
Statement $I$: In heteromorphic flowers,pollen grains produced from anther pollinate stigmas produced at same level.
Statement $II$: In Tobacco,the germination of pollen on the stigma of the same flower is inhibited.
In the light of above statements,select the correct option given below:

Which of the following prevents pollen germination or pollen tube growth?

In which plants do outbreeding devices prevent autogamy but not geitonogamy?

When male and female flowers are produced on different plants in a species,the condition is called:

Cleistogamy occurs in which plant?