Terms in this set (23)
Mutations will always decrease the activity of a gene.
A transposable element can insert into any position in the genome except
regions near the telomere.
regions near the centromere.
regions near sequences coding for ribosomal RNA.
inside another transposon.
Dosage refers to the number of copies of each gene in a cell.
An enzyme that uses the energy in ATP to close a nick in a DNA strand, joining the 3′ hydroxyl of one end to the 5′ phosphate of the other end.
postreplication mismatch repair
The correction of a mismatched base in a DNA strand by cleaving one of the strand backbones, degrading the sequence with the mismatch, and resynthesizing from the intact DNA strand.
base excision repair
A specialized repair system in which an incorrect DNA base and its sugar are both removed and the resulting gap is repaired
In base excision repair, a whole segment of DNA is removed and resynthesized.
A mutation that occurs in eggs and sperm or in the cells that give rise to these reproductive cells and therefore is passed on to the next generation.
Spontaneous mutations that occur in somatic cells will be transmitted to offspring.
synonymous (silent) mutation
A mutation resulting in a codon that does not alter the corresponding amino acid in the polypeptide.
Imagine a gene in which the sequence that is transcribed into a GAG codon, which codes for glutamic acid, is mutated to GUG, which codes for valine. What type of mutation is this?
Genetic risk factors
can increase the likelihood of diseases.
include mutations in the BRCA1 and BRCA2 genes.
can work synergistically with environmental risk factors.
can be heritable.
Any DNA "damage" is considered to be a mutation, even if it is immediately corrected by the action of DNA polymerase.
Chronic myelogenous leukemia (CML) is caused when a segment of chromosome 9 and a segment of chromosome 22 both break off and switch places. How is this mutation classified?
Which of the following mechanisms would most likely be involved in repairing a single point mutation?
mismatch repair and/or base excision repair
Mutation rates (per nucleotide per replication)
are highest in viruses.
In the sickle-cell anemia mutation, the 5′-GAG-3′ codon for glutamic acid becomes the 5′-GUG-3′ codon for valine. Assuming a single nucleotide substitution accounts for this mutation, what is the change in the DNA?
3′-CTC-5′/5′-GAG-3′ to 3′-CAC-5′/5′-GTG-3′
Which of the following enzymes is responsible for initiating certain types of base excision repair?
DNA uracil glycosylase
The use of antibiotics creates mutations in bacteria that make the bacteria resistant to these antibiotics.
A mutation in which a base pair is replaced by a different base pair; this is the most frequent type of mutation; also known as a nucleotide substitution.
When comparing DNA sequences of similar genes for proteins in related species, you see that some of the sequences are longer in one species compared to the other. Which of the following would most likely represent the extra number of bases that you would see?
Which of the following is the likely explanation for a flower showing multiple sectors with different coloration?
the result of transposable elements
Which of the following mutations would most likely have the most severe consequence?