Adish of animal cells was grown in the presence of radioactive phosphorus. the phosphorus largely ended up in nucleotides inside the actively growing animal cells. in which cellular structure(s) would you predict the majority of the radioactive phosphorous to accumulate

The cellular structure in which the majority of the radioactive phosphorus will accumulate is THE NUCLEUS.
This is because, we are told in the question that the phosphorus largely ended up in nucleotide inside the cells. The molecule that contains nucleotides inside the cell is the DNA and DNA is usually found in form of chromosomes, which are located in the nucleus of the cell.