Pre-mRNAs in eukaryotic cells undergo three main processing steps: Capping at the 5' end, the addition of a poly(A) tail at the 3' end, and splicing to remove introns. Which of the following statements about these steps is/are correct?
(i) The enzyme cap Mtase catalyzes the production of diphosphate 5'end.
(ii) Apart from the AAUAAA signal sequence, the UGUA signal sequence can also direct cleavage and polyadenylation.
(iii) The splicing reaction is catalyzed by the spliceosome.

A portion of the human gene is isolated and sequenced along with the corresponding mRNA to study the intron and splice site sequence present in a gene. Which of the following is the correct example of a normal splice site sequence found in an intron? 

Dr. Youneeb wants to determine the number of introns and exons in the human insulin gene. He isolated a segment of genomic DNA from a human somatic cell, fragmented and denatured it into single strands, and mixed it with a specific mRNA obtained from the cytoplasm of beta cells of the pancreas. After analyzing the hybridization pattern, he found that the DNA segment is hybridized to the mRNA at three sites while it remains unhybridized at two sites. So, can you tell what is the likely number of introns and exons in the human insulin gene?

Isoginkgetin is a chemical that inhibits RNA splicing. Which of the following statements about Isoginkgetin is true?

Which enzyme catalyzes the conversion of A to I and C to U in substitution RNA editing?

In polyadenylation, the enzyme polyA polymerase adds a chain of 100 to 250 adenine nucleotides to the mRNA molecule. The functions of polyadenylation include:

(i) Polyadenylation provides stability and prevents degradation.
(ii) It exports the mature mRNA from the nucleus to be translated to protein.