Which of the following is $NOT$ one of the seven pairs of contrasting traits studied by Mendel in pea plants?

Two allelic genes are located on

In a monohybrid cross of plants with red and white flowered plants,Mendel got only red flowered plants. On self-pollinating these $F_1$ plants,he got both red and white flowered plants in a $3:1$ ratio. Explain the basis of using $RR$ and $rr$ symbols to represent the genotype of plants of the parental generation.

Mark the odd one (w.r.t. true breeding line).

In Mendel's hybridization experiments,what is a pair of contrasting traits called?

The synthesis of starch in pea seeds is controlled by a single gene. This gene has two alleles,$B$ and $b$. If the shape of the pea seed is considered as the phenotype,what type of inheritance does this represent?