3. The cap that is added to the RNA during processing: (Select all that apply.) is needed for ribosomes to attach to messenger RNA. helps prevent rapid breakdown of the messenger RNA. helps prevent formation of complex three-dimensional structures in the messenger RNA. aids in the accuracy of translation of the messenger RNA into protein. 4. Which one of the following explains why rRNAS are the most abundant type of RNA in a mammalian cell? There are more different types of rRNA genes than all other types of genes combined. A different type of ribosome is needed to synthesize all of a cell's proteins, and because most proteins are present in multiple copies, a huge number of ribosomes are needed. None of the other answer options is correct. rRNAs are not the most abundant type of RNA in a mammalian cell. It takes several rRNAS to transcribe a single mRNA, so there are many more rRNAS needed in a cell than the number of proteins synthesized. There are rRNAs in ribosomes, and it takes millions of ribosomes to translate all the proteins required for a cell's functions.