A single-stranded sequence of DNA is shown.

TAC CGC AAG
Which series represents the complementary strand of DNA?

A. ATG GCG TTC

B. CGT TAT GGA

C. GCA ATA CCT

D. AUG GCG UUC

The correct option is (A).

Explanation:

The base-pairing rule illustrates the pairing of purine and pyrimidine bases in the construction of nucleic acids. Adenine and guanine are purines and pyrimidines are cytosine, thymine, and uracil.The total number of base-pair defines the size of the genome of an organism.

Uracil is exclusively present in the RNA. We can infer that purine base pairs with pyrimidine. So, adenine pairs with thymine in the DNA strand with the help of two hydrogen bonds and guanine pairs with cytosine that is supported by the presence of three hydrogen bonds.  

In case of RNA adenine forms double bond with the uracil residue.

answer: c

explanation:

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.