MODULE 3 ABIO314
During conjugation, if an Hfr cell is mated with an F- cell, why will the F- cell remain F-?
The cells would not stay in contact long enough for the entire Hfr genome to be transferred
Which of the following could result in frameshift mutation?
The deletion of two nucleotides in a codon
Frameshift mutations can be very severe. What is one reason why they are often so serious?
When a frameshift mutation occurs, it causes changes in many bases downstream and can affect many of the amino acids in the protein
Linking an ORF with a specific function is an example of gene
annotation
A mutant that has a nutritional requirement for growth is an example of a(n)
auxotroph
If a bacterium carrying a plasmid that confers resistance to ampicillin is placed into medium without ampicillin, it may
lose the plasmid because there is no selection for ampicillin resistance
Increasing genetic variability by the uptake of DNA from the environment is __________.
transformation
One group of chemical mutagens includes the base analogs. How do these lead to mutations?
When replication occurs, complementary base pairing may fail because the base analog may not be treated in the same way as the base that it replaced
Which of these organisms is likely to have the largest genome?
a yeast cell
The genetic code has many important characteristics. For example, a specific codon always means the same thing in a particular species. Codons mean the same thing in most species (even though there are some exceptions). In some cases, a particular amino acid can be specified by more than one codon (the genetic code is degenerate). Which of the following answers describes an example of the degenerate nature of the code?
AUU, AUC and AUA all code for lle
What is one of the changes that occurs when a cell contains an F plasmid that is NOT integrated into the chromosome?
Cell surface receptors change, preventing the uptake of more plasmids through conjugation
The SOS regulatory system is activated by
DNA damage
Transcriptome analysis is useful in relation to genome analysis because
It analyzes RNA, thus reveals which genes are expressed under different conditions
In DNA replication in vivo, RNA primers are used. However, researchers used DNA primers instead as they are more stable. Why might this be the case?
RNA has a relatively short half-life compared with DNA and doesn't need to be stable to perform its functions in the cell
Some bacteria have unusually high mutation rates. Is there an adaptive reason as to why they have high mutation rates?
These bacteria may be able to adapt rapidly to a new environment (e.g. an environment with an antibiotic)
Following uptake, transforming DNA becomes attached to a competence-specific protein that prevents it from nuclease attack until it reaches the chromosome.
True
Which of the following is NOT required for homologous recombination
a Hfr chromosome
A deleterious mutation in recA results in
a decrease in homologous recombination
A change in the nucleotide sequence of DNA that is passed on to daughter cells is referred to as
a mutation
F+ strains of Escherichia coli
have the F factor as a plasmid
You have preformed the following mating experiment using Hfr and F-strains of Escherichia coli: Hfr (thr +leu +gal +str^r) Which of the following selective media would you use to score recombinant colonies?
minimal medium + streptomycin
The addition of two bases to the genome of a prokaryote would be most damaging if located____
near the beginning of the coding region of a protein
In Sanger sequencing and in many newer sequencing techniques, labeled precursors are used. What are these precursors?
nucleotides that will be incorporated into the newly synthesized DNA
Which of the following features are common to transformation, transduction and conjugation
(1) UNDIRECTIONAL TRANSFER OF GENES (2) INCOMPLETE GENE TRANSFER (3) HOMOLOGOUS RECOMBINATION
The uptake of free DNA from the environment ________, while transfer of DNA with cell-to-cell contact would most likely result in ________.
transformation/conjugation
