Question

Wobble hypothesis for genetic code was given by
A)Bernfield and Nirenberg
B)Crick
C)Creighton
D)Hedges

Answer 1

Hint: Wobble hypothesis explains the degeneracy of genetic code and explains that more than one codon can code for a single amino during the process of translation.

Complete answer:
There are 61 codons that code for amino acids. However, there are less than 61 tRNA suggesting that anticodons of one tRNA read more than one codon. Additionally, in this reading the starting two base pairs of codons are important while the third codon remains unimportant. In this, the base at the first position of the anticodon is abnormal and pairs with more than one nitrogenous base at the third position of mRNA codon.

Abnormal bases include tyrosine, inosine and pseudouridine. This is called wobble base pairing. Let us analyze the options to find out the correct option.

Option A: Bernfield and Nirenberg were not responsible for giving the wobble hypothesis.Therefore, this is the incorrect option.

Option B: Crick proposed a wobble hypothesis in 1966. Therefore, this is the correct option.

Option C: Creighton showed that genes were present on the chromosomes.Therefore, this is the incorrect option.

Option D: Hedges did not propose the wobble hypothesis. Therefore, this is the incorrect option.

Hence, the correct answer is option (B)

Note: In wobble hypothesis, U pairs with A or G, G pair with U or C and I pairs with A, U, and C. The wobble hypothesis states that the third base of codon and first base of anticodon bind less tightly to each other than the other two bases of the codon. This makes the third base unimportant in many amino acids.