Design an experiment using a radioactive label that you could use to differentiate whether the virus

1. use radioactive Uracil. add it to a culture of virus infected lymph cells. let the virus replicate for a few generations. screen for radioactivity in virus. if the virus genome is DNA, no radioactivity should be detected. if the genome is RNA, the radioactive Uracil is incorporated into the virus genome.

2. just fill in the gaps in the second strand fragment (3'-->5') by the base pairing rules:

5'-CGTATGCGAAC-3'
3'-GCATACGCTTG-5'

then reverse the nucleotide sequence (remember to keep the orientation correct):

5'-GTTCGCATACG-3'
3'-CAAGCGTATGC-5'

Add a radioactive marker that only attaches to thymine...if the viral genetic material is radioactive, its DNA (which has thymine). if its not radioactive, its RNA (which has uracil instead of thymine)

One of the central differences between DNA and RNA is the T/U substitution. If you mark or label thymine, it's very easy to differentiate whether the virus contains DNA or RNA.

Thank you!