Number of Barr bodies in $XXXXY$ is
$1$
$2$
$3$
$4$
Normally $DNA$ molecule has $A-T, G-C$ pairing. However, these bases can exist in alternative valency status, owing to rearrangements called
Mendel published his work on inheritance of characters in $1865$ but it remained unrecognised till $1900$ because
$(a)$ He could not provide any physical proof for the existence of factors
$(b)$ His concept of factors as stable, discrete units that controlled the expression of traits did not find acceptance from the contemporaries
$(c)$ Mendel's approach of using mathematics to explain biological phenomena was totally old
$(d)$ Communication was not easy (as it is now)
Barr bodies (seen in saliva test in Olympic games) are found in human and are associated with
The term 'gene' was coined by
Study of human race is called