Genetics Ch 9 Quiz

We know that DNA and RNA (each with four nucleotide components) both use a three nucleotide genetic code and 64 codons (43 = 64). Knowing that the minimum number of codons for the genetic code is 21 (20 amino acids, 1 stop codon), what codon size would be required if only three nucleotides were present in the genome?

3 nucleotides per codon

The DNA sense (coding) strand for a particular amino acid is 5′-CAT-3′. What RNA sequence would be transcribed for this codon, what tRNA anticodon would recognize it, and what amino acid would be added in response to this codon?

5′-CAU-3′ (RNA sense); 3′-GUA-5′ (tRNA anticodon); histidine

How many nucleotides would be expected for a gene coding for a protein with 300 amino acids?

900

Formation of the peptide bond could be described as:

a ribosome-catalyzed dehydration reaction (H20 released).

The "wobble" base is less important than the other two nucleotides in a codon and is found:

at the 5′ end of the tRNA anticodon.

The anticodon on the tRNA molecule:

binds to the mRNA in a complementary fashion.

In vitro (in a test tube) translation of a synthetic RNA with the repeating sequence (AGA)20 could produce which of the following?

polypeptides containing arginine or polypeptides containing glutamic acid or polypeptides containing lysine

During the initiation of prokaryotic translation, a defect in IF3 function would generate:

premature association of the 30S and 50S subunits.

In bacteria, the Shine-Dalgarno sequence is found on the mRNA and is recognized by the ________________________ to reveal __________________________.

the 30S subunit; the translation START codon

Degeneracy in the genetic code is best illustrated by:

threonine codons.