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• A change in genetic material – usually the DNA
• A change in genetic material – usually the DNA
• Spontaneous and random; resulting from chance and not as a
response to need.
• A change in genetic material – usually the DNA
• Spontaneous and random; resulting from chance and not as a
response to need.
• Rate of mutations occurring can be increased by environmental
factors – exposure to mutagens.
• A change in genetic material – usually the DNA
• Spontaneous and random; resulting from chance and not as a
response to need.
• Rate of mutations occurring can be increased by environmental
factors – exposure to mutagens.
• Mutagens can be physical – radiation, or chemical –
formaldehyde.
• Mutations can involve whole genes when parts of a chromosome
are deleted, repeated, or trans located to other chromosomes.
• Mutations can involve who genes when parts of a chromosome
are deleted, repeated, or trans located to other chromosomes.
- Deleted mutations
• Mutations can involve who genes when parts of a chromosome
are deleted, repeated, or trans located to other chromosomes.
- Deleted mutations
- Repeated mutations
• Mutations can involve who genes when parts of a chromosome
are deleted, repeated, or trans located to other chromosomes.
- Deleted mutations
- Repeated mutations
- Translocation
• Mutations can involve who genes when parts of a chromosome
are deleted, repeated, or trans located to other chromosomes.
- Deleted mutations
- Repeated mutations
- Translocation
• These mutations can remove alleles from the gene pool, or
produce different combinations of alleles.
• Mutations can involve who genes when parts of a chromosome
are deleted, repeated, or trans located to other chromosomes.
- Deleted mutations
- Repeated mutations
- Translocation
• These mutations can remove alleles from the gene pool, or
produce different combinations of alleles.
• Can involve the addition of whole chromosomes (Eg – Down’s
syndrome, extra chromosome pair at 21. Total number of
chromosomes is now 47)
• Can involve the addition of whole chromosomes (Eg – Down’s
syndrome, extra chromosome pair at 21. Total number of
chromosomes is now 47)
• Removal of whole chromosomes (Eg – Turner’s syndrome. An
individual only has one sex chromosome instead of two (X).
• Can involve the addition of whole chromosomes (Eg – Down’s
syndrome, extra chromosome pair at 21. Total number of
chromosomes is now 47)
• Removal of whole chromosomes (Eg – Turner’s syndrome. An
individual only has one sex chromosome instead of two (X).
• This is known as aneuploidy – when an individual has more or
less than the diploid number (in humans it is 46)
• http://www.youtube.com/watch?v=efstlgoynlk
• Also known as point mutations – involve changes to the bases in
the DNA sequence = they occur within a gene.
• http://www.nhlbi.nih.gov/health/health-topics/topics/sca/
• Also known as point mutations – involve changes to the bases in
the DNA sequence = they occur within a gene.
• A change in the base sequence then results = producing a new
allele.
• Also known as point mutations – involve changes to the bases in
the DNA sequence = they occur within a gene.
• A change in the base sequence then results = producing a new
allele.
• 3 bases are called a triplet – these code for an amino acid –
which make up proteins.
** Any change in the bases making a triplet can change the amino
acid – changing the protein and so on.
• Also known as point mutations – involve changes to the bases in
the DNA sequence = they occur within a gene.
• A change in the base sequence then results = producing a new
allele.
• 3 bases are called a triplet – these code for an amino acid –
which make up proteins.
** Any change in the bases making a triplet can change the amino
acid – changing the protein and so on.
• If the protein changed from a point mutation is an enzyme, it
might not be able to act as a catalyst.
Gene
Enzyme
Substance X
Melanin
Skin Pigment
• A mutation in the gene that codes for the enzyme needed to convert substance X to
melanin means the enzyme’s structure is changed so it can no longer catalyse the
reaction. Melanin can’t be made, so the skin lacks pigment (albino)
Gene
Enzyme faulty
Substance X
No Skin Pigment (albino)
• http://www.med.umich.edu/yourchild/topics/genetic.htm
• If a mutation occurs in the cells that form gametes, the mutated
allele enters the gene pool of the population and becomes
subject to natural selection.
• If a mutation occurs in the cells that form gametes, the mutated
allele enters the gene pool of the population and becomes
subject to natural selection.
• If this new allele is beneficial (enhancing survival and
reproductive success) then it will be selected for and the
frequency will increase in the gene pool.
• If a mutation occurs in the cells that form gametes, the mutated
allele enters the gene pool of the population and becomes
subject to natural selection.
• If this new allele is beneficial (enhancing survival and
reproductive success) then it will be selected for and the
frequency will increase in the gene pool.