Question

1-

Which of the following statements about the use of synthetic polynucleotides in cracking the genetic code is true?

Group of answer choices

Particular codons are generated in predictable ratios with random RNA polymers containing specific ratios of different nucleotides.

Poly(A) RNA directs the synthesis of only polylysine in vitro.

Three different amino acids are incorporated into peptides when synthetic polymers of only one nucleotide are used to synthesize the RNA primer.

The codon table was completed by using RNA polymers of defined sequences.

2-

Because the genetic code is non-overlapping, a missense mutation (from a single nucleotide change) results in the alteration of ___________, and the resulting protein has _____________.

Group of answer choices

1st blank: three codons

2nd blank: up to three amino acid changes

1st blank: only one codon

2nd blank: at most, a single amino acid change

3-

Which of the following statements is a feature of the wobble hypothesis?

Group of answer choices

The wobble occurs only in the third base of the anticodon.

When inosine (I) is the first nucleotide of an anticodon, up to three different codons can be recognized by that tRNA.

tRNA molecules can recognize codons that specify two different amino acids.

An amino acid-specific tRNA molecule can recognize only one codon.

Answer 1

1. True statement about the use of synthetic polynucleotides in cracking the genetic code is - The codon table was completed by using RNA polymers of defined sequences.

Poly U RNA was used in that experiment performed by Nirenberg and Matthaei.

2.

Because of genetic code is non-overlapping , missense mutations results in the alteration of only and codon , and the resulting proteins has at most, a single amino acid change .

Missense mutation leads to one nucleotide change, so it affects only a single codon thus a single amino acid.

3.

When ionosine (I) is the first nucleotide of an anticodon, up to three different codons can be recognized by the tRNA_This statement is a feature of wobble hypothesis.

Wobble base pairing do not follow the standard Watson crick base pairing. It occurs between 3rd nucleotide of the codon and 1st nucleotide of the anticodon.