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12-4
What happens when there is a problem with the DNA sequence?
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Kinds of Mutations
Mutations are changes in the genetic material.
Many mutations have little or no effect on gene expression.
Some mutations are the cause of genetic disorders.
Many mutations have a profound effect on the organism.
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Kinds of Mutations
Kinds of Mutations
Mutations that produce changes in a single gene are known as gene mutations.
Mutations that produce changes in whole chromosomes are known as chromosomal mutations.
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Kinds of Mutations
Gene Mutations include:
Point mutations a change in one or a few nucleotides which occur at a single point in the DNA sequence.
Point mutations include
substitutions
insertions
deletions
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5. Kinds of Mutations/Gene Mutations (3 types)
Substitutions usually affect no more than a single amino acid.
Gene mutations result from changes in a single gene. In a substitution, one base replaces another.
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Kinds of Mutations
Insertions & Deletions
The effects of insertions and deletions are dramatic.
The addition or deletion of a nucleotide causes a shift in the grouping of codons.
Changes like these are called frameshift mutations.
Frameshift mutations change every amino acid that follows the point of the mutation.
Frameshift mutations can alter a protein so much that it is unable to perform its normal functions.
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7. Kinds of Mutations Gene Mutations (3 types)
In an insertion, an extra base is inserted into a base sequence.
Gene mutations result from changes in a single gene. In an insertion, an extra base is inserted into a base sequence.
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Kinds of Mutations
In a deletion, the loss of a single base is deleted and the reading frame is shifted.
Gene mutations result from changes in a single gene. The loss of a single letter in a sentence models the effects of the deletion of one base in a DNA sequence.
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Kinds of Mutations
Chromosomal Mutations 
Chromosomal mutations involve changes in the number or structure of chromosomes.
Chromosomal mutations include
deletions
duplications
inversions
translocations.
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12–4 Mutations
12-4 Mutations
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Kinds of Mutations
Deletions involve the loss of all or part of a chromosome.
Chromosomal mutations involve changes in whole chromosomes.
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Kinds of Mutations
Duplications produce extra copies of parts of a chromosome.
Chromosomal mutations involve changes in whole chromosomes.
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Kinds of Mutations
Inversions reverse the direction of parts of chromosomes.
Chromosomal mutations involve changes in whole chromosomes.
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Kinds of Mutations
Translocations occurs when part of one chromosome breaks off and attaches to another.
Chromosomal mutations involve changes in whole chromosomes.
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15. Significance of Mutations
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12–4
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12–4
A mutation in which all or part of a chromosome is lost is called a(an)
duplication.
deletion.
inversion.
point mutation.
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12–4
A mutation that affects every amino acid following an insertion or deletion is called a(an)
frameshift mutation.
point mutation.
chromosomal mutation.
inversion.
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12–4
A mutation in which a segment of a chromosome is repeated is called a(an)
deletion.
inversion.
duplication.
point mutation.
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12–4
The type of point mutation that usually affects only a single amino acid is called
a deletion.
a frameshift mutation.
an insertion.
a substitution.
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12–4
When two different chromosomes exchange some of their material, the mutation is called a(an)
inversion.
deletion.
substitution.
translocation.
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22. It’s ragning cats and dogs outnide
Substitution of g instead of i in raining
Substitution of n instead of s in outside.

23. It’s raining cats and frogs dogs outside
Insertion of the word frogs

24. It’s raining raining cats and dogs outside
Insertion (duplication) of the word raining a second time

25. It’s raining dogs outside.
Deletion of the word cats and the word and.

26. It’s raining edistuo sgod dna stac.
Inversion of the phrase cats and dogs outside.

27. It’s raining cats anfrogsd dogs outside.
Insertion of the word frogs in the middle of the word and.

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