Principle Of Inheritance And Variation Question 103
Question: Assertion : An mRNA has both initiation codon and termination codon. Reason : It specifies only a single polypeptide or number of them.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: B
Solution:
mRNA is a long RNA.
It gets attached to ribosome.
mRNA has methylated region at the 5? terminus.
It functions as a cap for attachment with ribosome.
Cap is followed by an initiation codon (AUG) either immediately or after a small noncoding region.
Then there is coding region followed by termination codon (UAA, UAG or UGA).
There is then a small noncoding region and poly A area at the 3? terminus.
An mRNA may specify only a single polypeptide or a number of them.
The former is called monocistronic while the latter is known as polycistronic.
BETA
