Question

In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand.

a. guanine ... adenine
b. cytosine ... thymine
c. cytosine ... uracil
d. thymine ... cytosine
e. uracil ... cytosine

Answer 1

Answer: Option D

Step-by-step explanation:

In a DNA double helix an adenine of one strand always pairs with a thymine of the complementary strand, and a guanine of one strand always pairs with a cytosine of the complementary strand.

Hence, the base composition of DNA shows that: adenine to thymine ratio is one (A/T = 1), while guanine to cytosine ratio is also equal to one (G/C = 1)