Mutations Flashcards
What is a mutation?
A permenant change in the genetic material
Where can mutations affect
A single point in a gene or larger sections of DNA
What sort of events are mutations?
Spontaneous/random
Mutant
Individual who inherits the trait
Mutagen
Something that induces a mutaiton
What are point mutations?
Minor changes to DNA and are often called single gene mutations
What are the three types of point mutations?
Substiution
Addition
Deletion
What point mutations are the msot devastating?
Addition
Deletion
What can substitution mutations sometimes lead to?
can result in a codon that still codes for the same amino acid
Misense Mutation
A point mutation where the chance in a single nucleotide causes the substitution of a different amino acid
Nonsense mutation
Point mutation which results in a premature stop codonin transcribed mRNA
Which are the most common form of mutations?
Substitutions
what do substitution mutations involve?
Replacement of one base by another, one codon may be altered so that now it codes for one different amino acid in the protein sequence.
What is the most detremential substituion mutation
1st or 2nd base of a condon is altered
What do insertion mutations cause?
A frame shift, affecting many codons
What occurs in deletion and what does it cause?
Nucleotide is deleted from the base sequence and a frame shift is caused.
What can chromosome mutations involve?
- Structural altercations of chromosomes
2. Changes in number of whole chromosomes within a nucleus
What is translocations
One choromosome attaches onto the end of another
What can translocations result in
May not seperate in meiosis
What are inversions
Occur when a single chromosome undergoes breakage and a segment of the chromosome is reversed end to end.
What are duplication mutations
A section of chromosome repeats
non-disjunction mutation
meiosos chromosomes do not seperate
result of non-disjunction
gametes produced will have too many or too few chromosomes.
What is aneuploidy
When an organism possesses an abnoormal number of chromomes
polyploidy
diploid gametes
