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5.Molecular Basis of Inheritance
medium
How many of the given statements $(i-iv)$ is/are correct?
$i.$ In transcription, adenosine pairs with uracil.
$ii.$ Regulation of lac operon by repressor is referred to as positive regulation.
$iii.$ The human genome has approximately $50,000\; genes.$
$iv. $ Haemophilia is a sex-linked recessive disease.
A
Two
B
Three
C
Four
D
One
Solution
Statement $(i)$ and $(iv)$ are correct. Regulation of lac operon by repressor is referred to as negative regulation. In negative regulation, a repressor molecule binds to the operator of an operon and terminates transcription. In positive regulation, an activator interacts with the $RNA$ polymerase in the promoter region to initiate transcription. Human genome contains some $20,000-25,000$ genes billion bases.
Standard 12
Biology