RNA has Uracil instead of Thymine. All the other three bases also occurs in RNA, adenine, guanine and cytosine. Therefore a ATA DNA codon will be transcript to UAU by RNA. Both Thymine and Uracil have the same role in however have minor chemical differences.
Somatic mutations can be passed on. B is the correct answer
So the plant doesn't freeze (; that was easy
Answer:
A) many noncoding stretches of nucleotides are present in mRNA.
Explanation:
A transcription unit in eukaryotes includes the region that code for mRNA extending from the 5' cap site to the 3' poly-A site. It also includes the controlling regions. The mRNA formed by transcription also has some non-coding intervening sequences. These are called introns. Introns are removed from the primary transcripts by the process of splicing that occurs after transcription.
Therefore, a transcription unit that is 8,000 nucleotides long may use only 1,200 nucleotides to code for a protein having 400 amino acids since the rest of the nucleotides are part of introns and are removed from mRNA after transcription.