Question

during dna replication, a dna strand that has the bases ctaggt produces a complimentary dna strand. which of the following is the complimentary dna strand that is produced?
a. tcgaac
b. gatcca
c. agcttg
d. gaucca

Explanation:

Step1: Recall DNA base pairing

In DNA, adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G).

Step2: Pair each base in CTAGGT

• C pairs with G
• T pairs with A
• A pairs with T
• G pairs with C
• G pairs with C
• T pairs with A

So the complementary strand for CTAGGT is GATCCA.

Step3: Eliminate incorrect options

• Option A (TCGAAC) does not follow the base - pairing rules.
• Option C (AGCTTG) does not follow the base - pairing rules.
• Option D (GAUCCA) has uracil (U), which is not present in DNA (uracil is in RNA), so it is incorrect.

Answer:

B. GATCCA