Which of the following did Mendel select for his experiments?

The method used to determine whether an individual is homozygous or heterozygous is known as:

Mendel's work remained unrecognized for a long time due to:
$I.$ Communication was not easy.
$II.$ The concept of factors which did not blend was not accepted.
$III.$ The use of mathematics to explain biological problems was unacceptable.
$IV.$ He could not provide any physical proof for the existence of factors.
Choose the right combination.

Who proposed the term 'Allelomorph'?

Which of the following terms represents a pair of contrasting characters?

When a true breeding pea plant that has yellow seeds is pollinated by a plant that has green seeds,all the $F_1$ plants have yellow seeds. This means that the allele for yellow is