Answer:
- Complementary base pairing between DNA and DNA consists of the way in which one DNA strand binds to another, by linking a pure base to a pyrimidine.
- Complementary base pairing between DNA and RNA occurs during transcription, where from the nitrogenous bases of the template strand, complementary nitrogenous bases are added to the RNA.
Step-by-step explanation:
The complementarity of nitrogenous bases consists of the union of a purine base and a pyrimidine base, allowing the bonding between two strands of a nucleic acid.
In DNA the purines are adenine (A) and guanine (G), while the primidines are cytosine (C) and thymine (T).
In RNA the purines are adenine and guanine, the pyrimidines being cytosine and uracil (U), since thymine is not found in RNA.
- Adenine is complementary with thymine, or with uracil, forming a double hydrogen bond.
- Cytosine is complementary to guanine and forms a triple hydrogen bond.
DNA with DNA DNA with RNA
A=T A=U
C≡G C≡G
Base pairing in DNA —DNA with DNA— is important in holding its two strands together, as well as in the replication process, which is carried out according to base complementarity.
DNA-RNA base pairing is observed during transcription where a purine base from the DNA template strand allows the incorporation of a pyrimidine into RNA, while a pyrimidine from DNA is complemented by a purine in RNA.