fen 24th -ch18th genetics

what leads to the generation of new alleles?

gene mutation

key components of a mutations

chromosome
dna
genes

mutations can occur near genes

categories of mutations?

somatic mutation

germ-like mutation (reproductive cell, passes to the next gen)

what is a codon?

set of 3 nucleotides that code for a specific amino acid

what is the reading frame?

series of codons that code for amino acids in a polypepetide chain

start with aug-meth

types of base changes?

transition: purine to purine a←>g and pyrimidine to pyrimidine c←>t;
transversion: purine to pyrimidine or vice versa. a←>c G←>T

different sequencing changes

base substitution: one codon is changed
base insertion: new nucleotides added, causing a shift in reading frame
base deletion: nucleotides removed, also causing a shift in reading frame

phenotypic effects for mutations

misense mutations: diff aa
nonsense mutations: results in a stop codon
silent mutation: no change in aa sequence

mutation types

forward mutation: changes wild type to mutant phenotype
reverse mutation: reverse mutant phenotypes back to the wild-type
suppressor mutation: suppresses or hides the effect of another mutation

transposition

a process where a segment of a dna moves from one location to another within the genome or between different dna molecules

coy and paste = increase total number

cut and paste= no change in total #