If natural selection in a particular environment favored genetic systems that permitted the production of daughter ʺcellsʺ that were genetically dissimilar from the mother ʺcells,ʺ then one should expect selection for

I. polynucleotide polymerase with low mismatch error rates.

II. polynucleotide polymerases without proofreading capability.

III. batteries of efficient polynucleotide repair enzymes.

IV. polynucleotide polymerases with proofreading capability.

V. polynucleotide polymerases with high mismatch error rates.

#Question id: 4235

#Unit 3. Fundamental Processes

What would be the consequence of a mutation in a bacterial cell that produces a defective aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA?

#Question id: 4236

#Unit 3. Fundamental Processes

In bacteria, there are 61 mRNA codons that specify an amino acid, but only 45 tRNAs. Which of the following statements explains this fact?

#Question id: 4237

#Unit 3. Fundamental Processes

A part of an mRNA molecule with the following sequence is being read by a ribosome: 5′-CCGACG- 3′ (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3′ to 5′ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form. Which of the following dipeptides will form from this mRNA?

#Question id: 4238

#Unit 3. Fundamental Processes

Use the following information to answer the question. A part of an mRNA molecule with the following sequence is being read by a ribosome: 5′-CCGACG- 3′ (mRNA). The following charged transfer RNA molecules (with their anticodons shown in the 3′ to 5′ direction) are available. Two of them can correctly match the mRNA so that a dipeptide can form.

#Question id: 4239

#Unit 3. Fundamental Processes

Use the figure to answer the question. What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?

#Question id: 4240

#Unit 3. Fundamental Processes

Use the figure to answer the question. The figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine). Which codon on the mRNA strand codes for this amino acid?