AP BIOLOGY

Detailed explanation-1: -There are two differences that distinguish DNA from RNA: (a) RNA contains the sugar ribose, while DNA contains the slightly different sugar deoxyribose (a type of ribose that lacks one oxygen atom), and (b) RNA has the nucleobase uracil while DNA contains thymine.

Detailed explanation-2: -Because thymine has a higher resistance to photochemical mutation and makes the genetic code more durable, DNA uses it instead of uracil.

Detailed explanation-3: -Uracil (U) is one of the four nucleotide bases in RNA, with the other three being adenine (A), cytosine (C) and guanine (G). In RNA, uracil pairs with adenine. In a DNA molecule, the nucleotide thymine (T) is used in place of uracil.

Detailed explanation-4: -Both DNA and RNA have four nitrogenous bases each-three of which they share (Cytosine, Adenine, and Guanine) and one that differs between the two (RNA has Uracil while DNA has Thymine).

Detailed explanation-5: -Uracil is one of four nitrogen bases, most frequently found in normal RNA. Uracyl can be found also in DNA as a result of enzymatic or non-enzymatic deamination of cytosine as well as misincorporation of dUMP instead of dTMP during DNA replication.