A number of structural modifications to the precursor messenger RNA (pre-mRNA) are required before this transcript is converted into a mature messenger RNA (mRNA) and used as a template for translation. What are the required structural modifications for for pre-mRNA to mRNA conversion, and in which compartment of the plant cell do they exclusively occur?
A. 5' cap addition, 3' poly A-tail addition, 5' and 3' UTR addition, intron removal / cytoplasm
B. 5' cap addition, 3' poly A-tail addition, 5' and 3' UTR addition, intron removal / nucleus.
C. 5' cap addition, 3' poly A-tail addition, intron removal / nucleus
D. 5' cap addition, 3' poly A-tail addition, intron removal / cytoplasm
Option B
B. 5' cap addition, 3' poly A-tail addition, 5' and 3' UTR addition, intron removal / nucleus.
Explanation:
Steps involved in structural modifications for pre-mRNA to mRNA conversion are :
Addition of a 5' cap at the beginning of the RNA
Addition of a poly-A tail (tail of A nucleotides) to the end of the RNA
Removing out of introns and pasting together of the remaining exons
Also UTR addition takes place in some mRNA
UTR is untranslated region of mRNA...it does not code any amino acid...
All these modification takes place in nucleus and translation step occurs in cytoplasm
A number of structural modifications to the precursor messenger RNA (pre-mRNA) are required before this transcript...