Mutations Deck (E3) Flashcards
What are the 2 primary genotype classifications?
Wild type & mutant
What 3 effects can mutations have on an organism?
1) Silent
2) Beneficial
3) Harmful
Change in a single base.
What is a point mutation?
What is the difference between an insertion and a deletion?
Insertion - addition of one or more bases
Deletion - subtraction of one or more bases
With this mutation, DNA is flipped in orientation.
What is inversion?
With this mutation, DNA mutates back to its original sequence.
What is reversion?
This mutation depicts no change in amino acid sequence.
What is a silent mutation?
This mutation depicts a change in one amino acid in sequence to another.
What is a missense mutation?
This mutation depicts a change that causes an amino acid sequence to end prematurely, resulting in a stop codon.
What is a nonsense mutation?
This mutation changes the reading frame of a gene.
What is a frame-shift mutation?
Physical or chemical agents that induce mutations.
What is a mutagen?
Spontaneous mutations occur in the { } of a mutagen.
Absence
What are 3 possible causes for spontaneous mutations?
1) Replication error
2) Metabolic damage
3) Transposons
What is the function of the enzyme transposase?
To move discrete DNA segments across the genome without an RNA intermediate
Another name for transposase.
What is an insertable sequence (IS)?
What do composite transposons do?
Carry other genes i.e., DNA segments flanked with 2 similar IS sequences
What 3 enzymes help with excision repair?
1) Endonuclease
2) DNA ligase
3) DNA polymerase
What are 2 methods of light repair (i.e., repair to DNA damaged by UV light)?
1) Direct repair
2) Photolyase
What type of light prompts photolyase to work?
Visible light
How does photolyase fix nucleotide dimers in DNA strands?
Visible light stimulates the enzyme to break the 2 pi bonds between the nucleotides
What is the purpose of induced mutations?
To demonstrate the function of a particular gene or set of genes
What type of assay does the Ames test use?
Mutational reversion
What is the purpose of the Ames test?
Testing the mutagenicity of compounds
The Ames test requires a histidine auxotroph. What does this mean?
A histidine auxotroph is a mutant organism requiring a particular nutrient to grow. In this instance, that nutrient is histidine
This type of selection detects mutant cells because they grow or appear different.
What is positive or direct?
This type of selection detects mutant cells because they do not grow.
What is negative or indirect?
What is the difference between positive and negative selection regarding the wild type?
Positive - eliminates wild type (b/c of mutagen)
Negative - selects for wild type
What is the difference between a mutant and a wild type?
Mutant - result of induced or spontaneous mutation
Wild type - all-natural w/o the mutations
