Question

question 9
what is the function of helicase?
o a it adds new nucleotides to the dna helix
o b it forms bonds between dna nucleotides.
o c it separates dna strands.
o d it forms the dna helix.

question 10
assume that two strands of dna have been separated and that the base sequence on one strand is ttgc. what is the
sequence of bases on the complimentary strand?
o a aacg
o b gtac
o c gcta
o d catt

Explanation:

Question 9

Helicase is an enzyme that functions in DNA replication. Its main role is to unwind and separate the double - stranded DNA molecule by breaking the hydrogen bonds between the complementary base pairs.

• Option a: Adding new nucleotides to the DNA helix is the function of DNA polymerase, not helicase.
• Option b: Forming bonds between DNA nucleotides (such as the phosphodiester bonds in the DNA backbone) is not the function of helicase.
• Option c: This is correct as helicase separates DNA strands.
• Option d: The DNA helix is formed by the complementary base - pairing and the overall structure of nucleotides, not by helicase.

In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). Given the sequence TTGC:

• The first T in the given strand pairs with A.
• The second T pairs with A.
• The G pairs with C.
• The C pairs with G.

Answer:

c. It separates DNA strands.

Question 10