Answer:
The correct answer will be option-B (purine).
Explanation:
Nucleic acid structure is made up of monomer unit called nucleotide. Each nucleotide is composed of a five-carbon sugar, a phosphate group and five types of nitrogenous bases.
The nitrogenous bases are categorized in two forms the purines (adenine and guanine ) and the pyrimidines (cytosine, thymine and uracil). The "purines" contain double rings in their structure due to which they appear larger in size than pyrimidines which are made up of single rings.
Thus, Option-B is the correct answer.
Answer:
The ten percent law states that the total energy content of a trophic level in an ecosystem is only about one-tenth (or 10%) that of the preceding level. The trophic levels of any ecosystem can be arranged in a pyramid shape to show the amount of energy available to support one trophic level to the next.
Less people and THE END OF THE WORLD
