Question

How many amino acids long polypeptide chains will be formed?

A. 45
B. 44
C. 135
D. 20

Answer 1

Hint: The central dogma is the important genetic process that occurs naturally in the cells. This process helps the DNA to be converted into RNA and ultimately in a protein that will encode for various processes and metabolisms. It was given by Francis Crick.

Complete answer: A polypeptide chain has various regions which help in the translation of the Nucleic acid.
1. Exons - They are the informative regions of the gene that can encode a protein.
2. Introns – They are the non-coding regions. They are spliced out before the RNA is translated.
In eukaryotes the exons and introns both are present but the introns are removed to make a functioning mRNA that can encode for a protein.
Some of the abbreviations in the figure are
UTR – Untranslated regions - they can be present at 5’ or 3’. They are important for the regulation of translation of the transcript. It is the non-protein-coding section of mRNA. The 5’ end UTR is used as the first codon in translation. The 3’ UTR is the last codon for translation.
AUG is the initiation codon and also codes for methionine.
UAA is the stop codon that will terminate the process of translation.
So in a polypeptide chain, only exons are considered
Here, $90 + 36 + 9 = 135$
Thus the correct answer is option C: 135

Note: The central dogma has 3 basic steps- replication, transcription and translation. It is an irreversible process as the protein cannot code back into the DNA. It forms the basic framework of the flow of genes in cells. The reverse transcriptase occurs in some viruses to convert the RNA into DNA.