Which one of the following ratio is constant in $DNAs$ of different species
$A + T / C + G$
$A + G / T + C$
$A + C / U + G$
$A + U / C + G$
The structure present over chromosome is
Plasmids so found in bacteria are
In the construction of chromosome maps, the evidence is derived mainly from
Cri-du-chat syndrome in humans is caused by the