Question

Which of the following statements about the DNA double helix is TRUE?

a) Complementary base pairing allows the production of identical copies of the template strand (or parts of the template strand) via RNA transcription and DNA replication
b) The 3' end of the double helix terminates in a nitrogenous base on the 3' carbon
c) It takes large amounts of energy to separate the double helix because it is held together via covalent bonds
d) The 5' end of the double helix terminates in a nitrogenous base on the 5' carbon
e) Complementary base pairing across the double helix allows information to be transferred via RNA transcription and DNA replication

Answer 1

The true statement about the DNA double helix is that complementary base pairing allows the production of identical copies via RNA transcription and DNA replication. The statement clarifies that the process uses the sequence of bases in one strand to create a complementary strand. The correct option is A.

Step-by-step explanation:

Among the given statements about the DNA double helix, the true statement is:
a) Complementary base pairing allows the production of identical copies of the template strand (or parts of the template strand) via RNA transcription and DNA replication. This is because, during DNA replication and RNA transcription, the sequence of bases in one strand of DNA is used as a template to create a complementary strand, whether it be a new strand of DNA or an RNA molecule.

Points to clarify:

• The 3' end of a DNA strand has a hydroxyl group attached to the 3' carbon of deoxyribose (the sugar), not a nitrogenous base.
• The helix is held together by hydrogen bonds between the complementary bases and not covalent bonds, which connect the sugar-phosphate backbone of the DNA.
• Antiparallel orientation means the 5' end of one strand is opposite the 3' end of the other.
• Only adenine (A) pairs with thymine (T) via two hydrogen bonds, and cytosine (C) pairs with guanine (G) via three hydrogen bonds.