Question

In eucaryotes, but not procaryotes, ribosomes find the start site of translation by:

a) Binding directly to a ribosome-binding site preceding the initiation codon.
b) Recognizing an AUG codon as the start of translation.
c) Scanning along the mRNA from the 5' end.
d) Recognizing a UAA codon as the start site for translation.
e) Binding an initiator tRNA to the large subunit.

Answer 1

The correct answer will be option-C

Step-by-step explanation:

The ribosome binding to the mRNA differs in both prokaryotes ad eukaryotes. as the mRNA of the prokaryotes is not modified after transcription with cap and tails at 5' end and 3' end receptively which are present in the eukaryotic mRNA.

The ribosome binds to the prokaryotic mRNA at a site called ribosome binding site (Shine-Dalgarno sequence) at 5' end but in eukaryotic mRNA has capping at 5' end so ribosomes bind this cap made of methyl guanosine and then scans the mRNA from 5' end till it finds the start codon- AUG and then starts the process of translation from AUG codon site.

Thus, Option-C is the correct answer.