Question

5 - aattgcatat - 3
what is the sequence of the complementary dna strand?
a ccggatgcgc
b tatacgttaa
c ttaacgtata
d uuaacguaua

Explanation:

Step1: Identify base pairing rules

DNA base pairs: A-T, T-A, G-C, C-G.

Step2: Reverse the template strand

Template: 5'-AATTGCATAT-3'. Reverse to 3'-TATACGTAA-5' (corrected length: original is 10 bases, so reversed is TATACGTAA).

Step3: Complement each base

Reverse template: T A T A C G T A A → Complement: A T A T G C A T T? No, wait original template is 5'-AATTGCATAT-3' (10 bases: A A T T G C A T A T). Reverse to 3'-T A T A C G T T A A-5' (10 bases). Complement each base: A pairs T, T pairs A, G pairs C, C pairs G. So 3'-TATACGTTAA-5' is the complementary strand (written 5' to 3' as AATTGCATAT's complement is TATACGTTAA when reversed? Wait no: complementary strand runs antiparallel. So 5'-AATTGCATAT-3' pairs with 3'-TTAA CGTATA-5' → written 5' to 3' is 5'-ATATGCTTAA-3'? Wait no, let's do each base:

Original: A A T T G C A T A T (5' to 3')
Complementary (3' to 5'): T T A A C G T A T A
Write as 5' to 3': A T A T G C A A T T? No, option B is TATACGT TAA (TATACGT TAA is 10 bases: T A T A C G T T A A). Let's check option B: TATACGT TAA (matches 3'-TATACGTTAA-5' which is the antiparallel complement of 5'-AATTGCATAT-3').

Answer:

B. TATACGTTAA