When an allele fails to express itself in the presence of another allele, the former is said to be

The number of contrasting characters studied by Mendel for his experiments was

$A$ human male is heterozygous for autosomal genes '$A$' and '$B$'. He is also hemizygous for the haemophilic gene '$h$'. What percentage of sperms will carry the '$abh$' genotype (in $\%$) (in $\%$)?

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

Which contributed to Mendel's success?
$I.$ Selection of pea plant
$II.$ Knowledge of history
$III.$ One character at one time
$IV.$ His statistical knowledge
Choose the correct option.

$A$ test cross cannot be performed in which of the following?