The number of hydrogen bonds between guanine and cytosine; and between adenine and thymine in DNA is
The number of hydrogen bonds between guanine and cytosine; and between adenine and thymine in DNA is
$1.2$
$3,2$
$3,1$
$2,1$
Solution
The only possible pairing in DNA are between $\mathrm{G}$ (guanine) and $\mathrm{C}$ (cytosine) through three $\mathrm{H}$-bonds i.e., $(\mathrm{C} \equiv \mathrm{G})$ and between A (adenine)
and $\mathrm{T}$ (thymine) through two $\mathrm{H}$-bonds (i.e., $\mathrm{A}=\mathrm{T}$ ) as shown in figure.
