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a strand of dna contains 10% adenine. what percentage of cytosine must be present in this strand of dna then?

a) 80%
b) 40%
c) 10%
d) 20%

Respuesta :

Answer:

[tex]\boxed {\boxed {\sf B. \ 40 \% \ cytosine}}[/tex]

Explanation:

First, recall the base pairs in DNA:

  • Adenine and Thymine
  • Cytosine and Guanine

We know this strand of DNA has 10% adenine. Since A and T pair, there must also be 10% guanine.

So, A and T make up 20% of the DNA strand.

That leaves 80% for cytosine and guanine. They are pairs, so they share this percentage equally.

  • 80/2 =40

There must be 40% cytosine and 40% guanine.

The strand of DNA has 40% cytosine