Question

(a) Differentiate between exons and introns.
(b) What is a plasmid? Why is it selected as a vector?

Answer 1

Answer:

Explanation:

a. exons are the sequences of mRNA that codes for proteins while the introns ate the sequences on mRNA that do not code for any protein ,hence they are needed to be removed .

b. plasmid is a semi circular self-replicating dna present in only prokaryotes that replicates independently of the genomic dna .

it is used as a cloning vector as it has its own ori(origin of replication )

and it does not affect the genomic dna  

Answer 2

(a) Difference between exons and introns are-

• Introns are the DNA segments which do not encode any amino acid sequence in the coding region while Extrons are the DNA segments which encode a part of an amino acid sequence of a complete protein.

• The sequence in Introns is less conserved while the sequence in Extrons are highly conserved.
• Introns belongs to non-coding DNA while the Extrons belongs to the coding DNA.

(b) A plasmid is an small extra chromosomal DNA molecule.It is selected as a vector because it serves in replication of DNA .