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What is a mutation?
Any change in DNA (the order of nucleotides (AKA the letters)
What are gene mutations? Give example(s)
changes the original DNA sequence
ex.) cystic fibrosis, dwarfism, sickle cell anemia
What are chromosome mutations? Give example(s)
changes the number or location of genes
ex.) Down Syndrome, Edward’s Syndrome, Turner Syndrome
What factors can cause a mutation? (2)
Mistakes that take place during significant cell processes
Viruses
What are mutagens?
Substances that can cause mutations
What are examples of mutations?
Secondhand smoke, UV light, radioactive substances
Are all mutations bad?
Mutations can be:
Neutral = no effect
Harmful = negative effect
Less able to survive, cancer, sickness, etc.
Beneficial = positive effect
Genetic variation → better able to survive
What are the two types of genetic mutations?
Point mutations and frameshift mutations
What are the three types of point mutations?
Missense
Nonsense
Silent
What is a missense point mutation? Give an example of missense mutation:
One changed nucleotide = changed amino acid
Original DNA: UUA, Mutation: GUA (Valina)
What is a nonsense mutation? Give an example of a nonsense mutation:
One changed nucleotide = stop codon INSTEAD of an amino acid
Original DNA: UUA, Mutation: UAA (stops codon)
What is a silent mutation? Give an example of silent mutation:
One changed nucleotide BUT still codes for same amino acid
Original DNA: UUA, Mutation: CUA (Leucine)
What are frameshift mutations? Give an example(s) of frameshift mutation:
Insertion/deletion of a nucleotide
ex.) ATTACC → ACTTACC = ?
ex.) ATTACC → ATACC = ?
How does frameshift mutation affect the codons?
Affect all the codons that come after them
Alters our “reading frame” of 3 codons
Why is it important to check for mistakes during mutations?
If the wrong information is copied during replication, protein synthesis could end up coding for harmful proteins that cause diseases and more! :(
