Download Mutations Notes

Mutations Notes

Mutations:
o
Mutations are _______________________ in the DNA code, which means changes in a
gene(s).
o
In gene mutations, the DNA code will have one or more bases _____________________
______________________________________________________ in a codon.
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How common are mutations?
o
______ in every 1 billion base pairs
o
______ in each cell in your body
How do mutations affect a population?
o
Mutations may be ______________________________________________________.
o
Mutations may be ______________________________________________________.
o
Mutations may have ______________________________________________________.
o
Mutations are a major source of _______________________________________ and
increase biodiversity.
o

Some variations may help populations to survive better.
How are mutations inherited?
o
Only mutations that occur in ______________________________ are passed onto
offspring.
o
Mutations in ____________________________ only affect the organism in which they
occur and are ____________________________________________________________.

Types of Mutations:
o
__________________________________________________ occur when the base
sequence of a codon or codons is/are changed
o
__________________________________________________ changes in the number or
structure of chromosomes.

Types of Point Mutations:
o
________________________________________
o
________________________________________
o
________________________________________
Also known as Frameshift mutations
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Substitution mutation – One base is changed for another
o This may or may not change the amino acid coded for by the codon
o
Practice:
o
________________________________________________________________________
THE
CAT
ATE
THE
RAT
Insertion mutations - a base is _____________ to the codon sequence
o This causes the codon ________________ to shift so we can continue to read the
bases in groups of 3
o This __________________ affects the amino acids in the sequence – from the
point of the mutation forward.
o Most damaging when it occurs at the ________________________ of the gene
sequence.
o
Practice:
o
________________________________________________________________________
THE
CAT
ATE
THE
RAT
Deletion mutations – a base is __________________ from the sequence
o Again, this causes a frame shift in the codons, affecting every amino acid from
the point of the mutation forward.
o
Practice:
o
________________________________________________________________________
THE
CAT
ATE
THE
RAT
__________________________ have the least effect on an organism because only one amino
acid may be changed, or it may cause no change at all.

____________________________ and _________________________________ mutations have
the most effect on an organism
o
Insertion and Deletion mutations affect many amino acids in the sequence, which will
affect the entire ________________________________________________________.

When do mutations have the greatest effect on an organism?
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What causes mutations?
o
_________________________________________________________
o
_________________________________________________________
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What is a mutagen?
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Chromosomal mutations:
o
Deletions –
o
Duplication-
o
Inversion –
o
Translocation –
o
Nondisjunction -