The mutations observed by the Lederbergs were

spontaneous

What protein cuts the damaged DNA strand?

UvrC

Which protein has a helicase function?

UvrD

Which of the following synthesizes the new DNA strand?

DNA polymerase

A mutation has occurred that prevents UvrA and UvrB from forming a complex. What result will this have on damaged DNA?

The damaged DNA will not be recognized.

A mutation has occurred that has made UvrD non-functional. What result will this have on damaged DNA?

The damaged segment of DNA will be recognized and cut, but it will not be separated from the healthy strand.

Somatic cell mutations are heritable.

false

Which of the following is an example of a mutation?

During replication, an A-T base pair in a gene is changed to a G-C base pair.

If a frameshift mutation causes a stop codon to be inserted into the DNA sequence

the resulting protein will be too short and non-functional.

A nucleotide deletion in DNA replication

causes the amino acids inserted after the deletion to be incorrect.

A deletion occurs during DNA replication, causing the guanine shown in red to be removed from the nucleotide strand. What effect is this most likely to have on the final protein?

The deletion of the G will cause a frame shift, resulting in a premature stop codon and a truncated protein.

In the Ames test for mutagenicity, why was rat liver extract included in the control sample?

Rat liver extract contains enzymes that may be necessary for certain mutagens to work. Since it must be added to the experimental sample, it is also added to the control sample.

Consider the mutated sequence for Tay Sachs Disease. How many amino acids are changed by the insertion mutation?

All of the amino acids starting at the site of the insertion

Using the genetic code, what mutation could happen at this same site that would result in a silent mutation?

None, both codons for Glu have an A as the second nucleotide

A mutation in a gene in the fruit fly Drosophila was found to affect eye color. The protein affected was found to be completely normal in its molecular weight and amino acid sequence, although much less of the protein is made in mutant flies. A reasonable explanation for the change in levels of protein is that the mutation

occurs in the promoter of the gene, within several hundred base pairs of the start of transcription.

The timing of a mutation during development has negligible effects on the severity of the genetic defect.

false

Which of the following could not result from mutations?

A fish in a stream dies from a poison that blocks cellular respiration.