Number of Barr bodies in $XXXXY$ is
$1$
$2$
$3$
$4$
Which one of the following is a physical factor that induce mutation?
Blood bank of the body or reservoir where the blood is stored and can be mobilized, is
$A$ : The heterozygotic female for haemophilia may transmit the disease to sons.
$R$ : Such traits show criss-cross inheritance
What are the characteristic features of a true-breeding line ?
The first plant in which chromosomal basis of sex determination was discovered is