Genome and mutations Flashcards
Any change in the information content of genetic material
Mutation
A change in the identity of an single base at a specific position in a nucleic acid sequence.
Point mutation
A point mutation involving the replacement of a purine base by another purine base or of a pyrimidine base by another pyrimidine base.
Transition
A point mutation involving the replacement of a purine base by a pyrimidine base or vice versa.
Transversion
What is the difference between missense and nonsense mutations?
Missense converts a codon specifiying an amino acid to another codon specifying a different amino acid. Nonsense converts a codon specifying an amino acid to a stop codon, which prematurely terminates translation.
Mutation that converts a stop codon into a codon that specifies an amino acid, causing translation to proceed beyond the codon
Readthrough
Mutation that inserts or deletes one or more nucleotide residues within a codon sequence, resulting in a shift in the reading frame of the sequence downstream.
Frameshift
Which of the following refers to the term, genome?
A. All genes B. All nuclear genes C. All nuclear and organellar genes D. All DNA sequences in haploid chromosomes E. All nuclear DNA
D
In comparative genomics, what aspects of the organism are being compared?
A. Metabolites
B. Genes
C. DNA sequences
D. Protein sequences
C
Which of the following would result from a silent mutation in a gene?
A. A truncated protein
B. A shift in the translational reading frame
C. The nucleotide sequence of the mRNA encoded by the gene remains unchanged
D. The amino acid sequence of the protein encoded by the gene remains unchanged
D
BLAST of your unknown protein gave a hit in the database for proteinase K with an e value of e—100 Which of the following would BEST characterize the genes encoding these two proteins?
A. They are functionally unrelated.
B. They function in the same tissue.
C. They encode a dimeric protein complex
D. They are derived from similar species.
D
Which of the following would BEST explain why in bacterial production of mammalian proteins, a cDNA is used rather than genomic DNA?
A. It is not possible to clone the entire coding region of the gene.
B. It is easier to clone cDNA than genomic DNA of comparable size.
C. It is easier to clone RNA than DNA.
D. Most eukaryotic genes have introns that cannot be removed in bacteria.
D
Which of the following is of LEAST importance in comparative genomics?
A. Subcellular structures
B. DNA sequences
C. Sequence alignment software
D. Sequence databases
A
In which level of comparative genomics resolution does synteny fall?
A. High
B. Medium
C. Low
D. None of the above
C
Which of the following drives a regulated endogenous mutation process?
A. Action of activation-induced cytidine deaminase (AID)
B. Spontaneous thymine-thymine dimerization
C. Activity of low fidelity polymerases
D. All of the above
E. A and C only
E
Which of the following statements is INCORRECT?
A. Point mutations may result in the production of truncated gene products.
B. Point mutations may have no effect on translated amino acid sequences.
C. Point mutations may produce shifts in reading frame.
D. Insertion-deletion mutations may produce shifts in reading frame.
C