AP BIOLOGY

Detailed explanation-1: -Ribonucleic acid (abbreviated RNA) is a nucleic acid present in all living cells that has structural similarities to DNA. Unlike DNA, however, RNA is most often single-stranded. An RNA molecule has a backbone made of alternating phosphate groups and the sugar ribose, rather than the deoxyribose found in DNA.

Detailed explanation-2: -Correct Option-(a) one of the bases from DNA is replaced by uracil.

Detailed explanation-3: -RNA, abbreviation of ribonucleic acid, complex compound of high molecular weight that functions in cellular protein synthesis and replaces DNA (deoxyribonucleic acid) as a carrier of genetic codes in some viruses.

Detailed explanation-4: -Ribonucleic acid, or RNA, is named on the bases of ribose sugar group found in backbone. In 1953, Alexander Rich with famed chemist Linus Pauling discovered the structure of RNA at Caltech using X-ray crystallography.