8.1 Mutations Flashcards
What is a point/gene mutation?
change in DNA base sequence
changes the amino acid sequence
changes primary structure
changes tertiary structure
changes the function
When does a point mutation occur?
during DNA replication in interphase
What increases the chance of mutations?
mutagens
Why are mutations a good thing?
important for an organism to live through natural selection
the population can evolve
What is a chromosome mutation?
a change in the number of chromosomes - extra/less
When does a chromosome mutation occur?
during meiosis in anaphase 1 or 2
What are all the different types of point mutations?
substitution
insertion
deletion
duplication
inversion
transloaction
What is substitution mutation?
only 1 amino acid is changed in the sequence
Why does a substitution reaction have little effect?
degenerate code - can code for the same amino acid so its a silent mutation
What is insertion mutation?
adding an extra base to the sequence
What is a frameshift?
every codon downstream of the mutation will change so potentially every amino acid downstream of the mutation will change
What is deletion mutation?
removal of a base
What is duplication mutation?
the base that came before is copied and inserted
What is inversion mutation?
a group of bases becomes separated from the DNA and rejoin in reverse order
What is translocation mutation?
bases are separated from DNA sequence and one chromosome is inserted in a different chromosome