AP BIOLOGY

THE MOLECULAR BASIS OF INHERITANCE

DNA MAKES RNA MAKES PROTEIN

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
If a DNA strand reads ATT CGT CTA, what would the mRNA strand read?
A
TAA GCA GAT
B
CGA TGA GUT
C
UAA GCA GAU
D
TAA GCA GUT
Explanation: 

Detailed explanation-1: -The enzyme that converts DNA into mRNA is called RNA polymerase, which attaches to the DNA double helix as shown here. Once attached, RNA polymerase can unwind the helix and begin copying one of the DNA strands to form an mRNA transcript of the gene.

Detailed explanation-2: -Determining mRNA Sequence RNA also uses four bases. However, instead of using ‘T’ as DNA does, it uses uracil (U). Therefore, if your DNA sequence is 3’ T C G T T C A G T 5’, the mRNA sequence would be 5’ A G C A A G U C A 3’.

Detailed explanation-3: -mRNA is formed as a complementary strand to one of the two strands of the DNA. Three of the four nitrogenous bases that make up RNA-adenine (A), cytosine (C), and guanine (G)-are also found in DNA. In RNA, however, a base called uracil (U) replaces thymine (T) as the complementary nucleotide to adenine.

There is 1 question to complete.