AP BIOLOGY

Detailed explanation-1: -Uracil is present only in RNA, whereas thymine is present only in DNA. Thus, thymine is the nitrogenous base which is not present in RNA.

Detailed explanation-2: -2. Which of the following are not the components of RNA? Explanation: Thymine is present in DNA but not in RNA.

Detailed explanation-3: -DNA contains four bases which are adenine (A), guanine (G), cytosine (C) and thymine (T). RNA also contains four bases, the first three bases are same as in DNA but the fourth one is uracil (U).

Detailed explanation-4: -Adenine and guanine are found in RNA and DNA in terrestrial life, whereas thymine is only found in DNA and uracil only in RNA.