The recessive genes located on $X$-chromosome in humans are always
Lethal
Sub-lethal
Expressed in males
Expressed in females
Excessive growth of hair on the pinna is a feature found only in males because
___$(B)$___ used the frequency of recombination between gene pairs on the ___$(A)$___ as a measure of the distance between genes and mapped their position on the chromosome
$(A) \;\;\quad\;\;(B)$
Polytene chromosomes in salivary glands of Drosophila are formed as a result of
Generation of non-parental gene combinations is termed as
Somaclonal variation appears in