Answer:
18 >> ATTAGACA: 2+2+2+2+3+2+3+2 = 18 H-bonds
Explanation:
Adenine (A) pairs with Thymine (T) through two hydrogen bonds (A=T), whereas Cytosine (C) pairs with Guanine (G) through three hydrogen bonds (G=C). In consequence, the bond between C and G (G=C) is more stable. In this case, six (6) A=T pairs and two (2) G=C pairs are formed, thereby the number of H-bonds is equal to (6 x 2) + (2 x 3) = 18.
