Point Mutations

Define Point Mutations:

\-change in one or few nucleotides

\-can result in change in protein

What are three different types of Point Mutations?

\-substitution

\-frameshift

\-mismatched base pairs

Define Frameshift

\-shift codon reading frame used by a ribosome

\

Define insertion and deletion:

\-insertion: one nucleotide is input into the sequence

\-deletion: one nucleotide is deleted from the sequence

Define mismatched base pairs:

\-base pairs are mismatched/incorrectly paired

What are causes of mutations:

\-errors in meiosis


1. chromosomes don’t separate properly


1. nondisjunction = aneuploid = monoploid/triploid no copies of chromosomes
2. Errors in DNA replication = mismatched pairs

What are some environment causes for mutations?

\-radiations = UV and x-ray

\-chemicals = cigarettes, preservatives, cosmetics, aerosols, plastics. . .

Define substitution

\-one nucleotide change in sequence

Define silent mutation:

no affect on protein

Define missense mutation:

protein change/amino acids change

Define nonsense mutation:

\-protein production stops