What is true about tRNA's: O they vary widely in size O they can covalently bond to more than one type of amino acid 0 they do not have any stem loop structures O they contain an anticodon triplet that recognizes a mRNA codon 0 there are exactly 20 different tRNA's

Option (3).

Explanation:

Transfer RNA or t RNA's is one of the type of the RNA molecule necessary for the synthesis of protein translation. This RNA works as a adaptor molecule and contains 70 to 90 nucleotide in length.

Transfer RNA contains an anti codon loop. This anti codon loop has the ability to recognize an mRNA codon and result in the formation of protein product.

Thus, the correct answer is option (3).