Question

Origin of replication usually contains

• A. GC Rich Sequences
• B. GCG-Rich Sequences
• C. No particular stretch of Sequences
• D. AT-Rich Sequences

Hint:

AT-rich regions are preferred at the origin of replication because \[ \boxed{ \text{A--T pairs have only two hydrogen bonds,} } \] making DNA unwinding easier.

Answer 1

The Correct Option is D

Step 1: Recall the origin of replication. The origin of replication (Ori) is the specific DNA sequence where DNA replication begins.

Step 2: Identify its characteristic feature. Origin of replication generally contains \[ \boxed{\text{AT-rich sequences}.} \] Since adenine-thymine (A--T) base pairs are connected by only two hydrogen bonds, they separate more easily than G--C base pairs during DNA replication. Hence, \[ \boxed{\text{AT-Rich Sequences}} \] is the correct answer. Therefore, \[ \boxed{(D)} \] is the correct answer.