mutations

Sources of mutation

Replication errors in dna and rna

Environmental: radiation, chemicals, infectious agents

Mutations that influence evolution

Germline/reproductive tissue on ovaries and testis with mutations get passed down to offspring not somatic

Point mutations/substitutions

One base change to another

Nonsynonomous: aa change so function change

Synonymous: (silent) same aa same function

Nonsense: premature stop codon

Transition: purines (a to g) prymadins (t to c)

Trans version: (a/g to t/c) purine to prymadin

Frameshift mutation

Insertion/deletion usually in three shifts entire codon reading

Substitution effects ranked

Phenotypic and frequency after selection

Sickle cell example

Amino acid change by substitution results in many phenotypic changes like blood cell shape, o2 binding altered and lifespan shortened

Mutations neutral by

Synonymous changes

Nonsynonymous changed aa to similar aa so protein has similar/same function

Effect of mutation depends on environment: wild type outperforms mutant in favorable conditions but under stress results in a more neutral effect

Could affect part of protein not important to function ex. Certain parts of spike proteins on COVID

Chromosomal mutations

Deletion big affect

Duplication could be big effect

Inversion common

Translocation one part moved to different part

Genome duplication

Tetraplois and diploid have diploid and haploid gametes when reproduce results in triploid which dies off causing speciation between the two

Pleiotropy

Allele affects multiple traits

Mutations are usuallypleiotropic

Has genetic correlation, neutral mutation bc of trade off, epistasis

Mutations are

Generally bad or neutral

Lederberg experiment

penicillin resistance mutations occurred before the

addition of penicillin, not in response to it Because original colony had same results as copied colony