The dna of eukaryotic cells has many copies of genes that code for rrna molecules. suggest a hypothesis to explain why a cell needs so many copies of these genes

A DNA sequence that codes for ribosomal RNA (rRNA) is called ribosomal DNA. There is from 50 to 5,000 sets of rRNA genes in eukaryotic genome, since the rRNA is critical for making ribosome to carry out protein synthesis. rRNA has an active role in recognizing conserved portions of mRNAs and tRNAs, so it must be made in sufficient quantities to keep up with a cell's demands for proteins.

hey, i believe your answer would be d. sugar ribose and the base uracil. i believe this is the answer, because rna consists of sugar ribose, adenine, guanine, cytosine, and uracil.

your first option is incorrect, because that's dna. where it consists of sugar deoxyribose, adenine, guanine, cytosine and thymine.

your second option is also incorrect, this is because sugar deoxyribose is in dna, and uracil is in rna. these two do not make sense together.

your third option being incorrect, because sugar ribose is in rna, but not the base of thymine. rna consists of uracil, not thymine.

lastly your fourth option being correct! this answer is correct, because both sugar ribose, and the base uracil are in rna! ~

answer is d. sugar ribose and the base uracil.