Question

which double-stranded dna molecules will be held together the most tightly? aattggc ttaaccg aattaaa ttaattt gcttggccgaaccg gcgcggccgcgccg aattagc ttaatcg

Explanation:

Double-stranded DNA stability depends on hydrogen bonds between base pairs: G-C pairs form 3 hydrogen bonds, while A-T pairs form 2. The DNA molecule with the highest proportion of G-C pairs will be held most tightly. Among the options, GCGCGGC CGCGCCG has the highest number of G-C pairs, leading to the strongest bonding.

Answer:

D. GCGCGGC CGCGCCG