Answer:
as the field of science, biology help as to understand the living world and the ways it's many species
Fossil fuels coal<span>, </span>petroleum, and natural gas <span>are our main sources of energy
, these sources gives us energy and producing the vast majority of fuel,</span>electricity<span>, and heat used by people across the globe but cause the global warming and increase the temperature of the earth
hope it helps</span>
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.
