Please, explain - saad_usmle

[ArchivalUser]

This question drove me crazy. The answer is D. But I just cannot get it How can I know how many codons from the start codon to the termination. Maybe I didn't understand the question. Please, for help!
The quesion:
A gene encodes a protein with 150 amino acids. There is one intron of 1,000 bps, a 5'-untranslated region of 100 bp, and a 3'-untranslated region of 200bp. In the final processed mRNA, how many bases lie between the start AUG codon and the final termination codon?
A. 1,750
B. 750
C. 650
D. 450
E. 150

[ArchivalUser]

-----untranslated 5'------AUG-----AA----intron------AA-----termination codon---untranslated 3'----

so: only 150AA, 450bp

[ArchivalUser]

hey its like this --
when u form mRNA - all u have is exons --introns are removed by splicing ...
5'UTR and 3'UTR not translated so that means they also wont come.

so watever mRNA u formed only has exons -
now we have formed protein of 150 aminoacid from this mRNA
150 X 3 = 450
why 3 becoz 3 nucleotide code for one amino acid ..
i hope its clear

[ArchivalUser]

I am agree with that

[ArchivalUser]

very clear thanks dronna....

[ArchivalUser]

Thanks drona99. I think I got it now My problem was with understanding the question stem.
I know about the introns, exons and the untralslated regions. My probelm was with the bases and the question was vague.
So I can put it now as the following according to my understanding and correct me if I am wrong.
codon has 3 nucleotides (means 3 bases):
one codon-----------> one amino acid:
that means 3 bases----------> one amino acid
that means 450--------------> 150 amino acids
Is that correct?
Thanks for all the inputs, guys!