Question

The ratio constant for a species is ______.

Options

• A + G/C + T

• T + C/G + A

• A + C/T + G

• G + C/A + T

Answer 1

The ratio constant for a species is G + C/A + T.

Explanation:

Chargaff’s rule gives equal amounts of A and T, and of G and C; the ratio of G + C to A + T is constant for a species. The other listed ratios do not express this species-specific ratio.