Question

How many different types of RNA polymerases are involved in synthesis of all rRNA of $80s$ ribosome?

• A. Four
• B. Three
• C. Two
• D. One

Answer 1

The correct option is C Two

Ribosomal ribonucleic acid (rRNA) is the RNA component of the ribosome. There are four different types of rRNA in 80s ribosomes, namely 28s rRNA, 18S rRNA, 5S rRNA, and 5.8S rRNA. There are three types of RNA polymerases, namely RNA polymerase I, RNA polymerase II and RNA polymerase III. RNA polymerase I is involved in the synthesis of 18S, 5.8S and 28S rRNA. RNA polymerase II is involved in synthesis of messenger RNA (mRNA). RNA polymerase III is involved in the synthesis of tRNA, 5SrRNA. Hence, there are two types of RNA polymerases involved in synthesis of all rRNA of 80S ribosome.

Thus, the correct answer is option C.