AP BIOLOGY

Detailed explanation-1: -mRNA is a complementary copy of a DNA segment (gene) and consequently can be used to deduce the gene sequence. For converting a sequence from mRNA to the original DNA code, apply the rules of complementary base pairing: Cytosine (C) is replaced with Guanine (G) – and vice versa. Uracil (U) is replaced by Adenine (A)

Detailed explanation-2: -Answer and Explanation: For the sequence 5’-GATTACA-3’, the complementary DNA strand would be 3’-CTAATGT-5’. Often, DNA strands are written in the 5’ to 3’ direction, so the complementary strand would be 5’-TGTAATC-3’ when written 5’ to 3’.

Detailed explanation-3: -If one strand of a DNA molecule has the sequence of bases 5’ATTGCA3’, the other complementary, antiparallel strand of DNA would have the sequence: 5’TGCAAT3’.

Detailed explanation-4: -In DNA/RNA base pairing, adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G). The conversion of DNA to mRNA occurs when an RNA polymerase makes a complementary mRNA copy of a DNA “template” sequence.