Question

The bases of RNA are the same as those of DNA with the exception that RNA contains_______.
1. cysteine instead of cytosine 2. uracil instead of thymine 3. cytosine instead of guanine 4. uracil instead of adenine

Answer 1

DNA contains four nitrogenous bases - adenine, thymine, cytosine and guanine. RNA also contains four bases. But instead of thymine, uracil is present.

The answer is 2. The bases of RNA are the same as those of DNA with the exception that RNA contains uracil instead of thymine