Answer:
The correct answer is option A) "Sequence of bases".
Explanation:
Even though DNA most of the time is comprised entirely of only four different nucleotide bases (adenine, thymine, guanosine and citosine), it is the sequence of these bases that allows DNA to carry a vast amount of hereditary information. The genes that carry the hereditary information are translated according to the sequence of the DNA bases. The information is translated by triplets of bases (codons) that correspond to different amino acids that are added to new synthesized proteins during translation.
In the coding region, natural selection tends to eliminate all of the mutations because of the high importance these regions have. The coding region contains genes that synthesize proteins and the changes in the DNA sequence can have devastating effects on the cell. Therefore, there are very few differences in the sequences of coding regions that can help us trace the lineage.
On the other hand, in the non-coding regions, the mutations often accumulate because they have little effect on the cell and the adaptive value of the organism. This enables us to trace up the lineage by comparing the sequences and seeing the differences in the sequences.
Fossil fuels and green house gases which burn holes in the ozone layer of the atmosphere causing global warming
