What is the function of rRNA?

Question

please no wrong answers.

Answer 1

http://en.wikipedia.org/wiki/Ribosomal_RNA

Answer 2

Ribosomal RNA (rRNA) is the primary constituent of ribosomes. Ribosomes are the protein-manufacturing organelles of cells and exist in the cytoplasm. rRNA is transcribed from DNA, like all RNA. Ribosomal proteins are transported into the nucleus and assembled together with rRNA before being transported through the nuclear membrane. This type of RNA makes up the vast majority of RNA found in a typical cell. While proteins are also present in the ribosomes, solely rRNA is able to form peptides. Therefore ribosome often is referred to as ribozyme.

Mammalian cells have 2 mitochondrial (23S and 16S) rRNA molecules [1] and 4 types of cytoplasmic rRNA (28S, 5.8S, 5S (large ribosome subunit) and 18S (small subunit)). 28S, 5.8S and 18S rRNAs are encoded by a single transcription unit organized into 5 clusters (each has 30-40 repeats) on the 13,14,15, 21 and 22 chromosomes. These are transcribed by RNA polymerase I. 5S occurs in tandem arrays (~200-300 true 5S genes and many dispersed pseudogenes), the largest one on the chromosome 1q41-42. 5S rRNA is transcribed by RNA polymerase III.

Cytoplasmic rRNA genes are highly repetitive because of huge demand of ribosomes for protein synthesis ('gene dosage') in the cell.

Answer 3

it reads the codons of the mRNA.