Module 6: Genetic Change
Mutation
Inquiry question: How does mutation introduce new alleles into a population?
Students:
● explain how a range of mutagens operate, including but not limited to:
- electromagnetic radiation sources
- Chemicals
- naturally occurring mutagens
● compare the causes, processes and effects of different types of mutation, including but
not limited to:
- point mutation
- chromosomal mutation
● distinguish between somatic mutations and germ-line mutations and their effect on an
organism (ACSBL082, ACSBL083)
● assess the significance of ‘coding’ and ‘non-coding’ DNA segments in the process of
mutation (ACSBL078)
● investigate the causes of genetic variation relating to the processes of fertilisation,
meiosis and mutation (ACSBL078)
● evaluate the effect of mutation, gene flow and genetic drift on the gene pool of
populations (ACSBL091, ACSBL092)
Mutation: a mutation refers to a change in the base sequence of an organism's DNA
Mutations can be caused by:
- Mutagen: environmental agent which damages the DNA
- Cellular error: cell makes a mistake during cell division
● explain how a range of mutagens operate, including but not limited to:
- electromagnetic radiation sources
- Chemicals
- naturally occurring mutagens
Mutagen: an agent which can change the structure of DNA causing a mutation
Chemical mutagen: cause a change in DNA that alters the function of proteins and as a result the cell
will not function properly
- Eg. ingested chemicals: alcohol, tobacco, cleaning products
- Effects: results in the assertion of incorrect nucleotides opposite to their complementary
bases, termed mispairing
- Results in non functional proteins
Biological mutagens: Microbes: fungi, viruses, some bacteria
- Effects: mutagenic microbes are able to insert their own base sequence into DNA of the hosty
and change the functioning of genes and trigger cancer
- Can cause inflammation, reduce repair systems, increasing mutations
Physical mutagens: heat, ionizing radiation
- Effects: heat and ionising radiation can carry enough energy to breach chemical bonds in the
DNA
- Cause skin cancer and can prevent replication and transcription
, Electromagnetic Radiation:
- Waves which carry electromagnetic energy
- Only ones with short wavelength and high energy waves can cause mutation
- UV light, x-rays and gamma rays
Sources of
electromagnetic
radiation:
1. The sun is
the biggest source of EM radiation in everyday life (UV light)
2. Radioactive elements such as uranium-236.
- Release gamma rays as they decay
- Mde by chemistry lads or nuclear bombs
3. Medical imaging machines
- X ray machines, PET scanners
Chemicals:
- Different chemicals cause mutations in different ways
- Chemical is accidentally incorporated into DNA instead of proper nucleotides eg. 5-BDU
- Chemical inserts itself into the DNA eg actinomycin D
- Chemical makes gaps in the DNA eg. dimethyl sulfate
Naturally occurring mutagens:
- Mutagenic chemicals which specifically come from microbes, plants and animals
Microbe:
- Mycotoxins are poisonous chemicals produced by fungi
- Most likely to encounter
- Eg. aflatoxin B1 - inserts itself into DNA and distorts it
Plants:
- Cysain is a mutagenic chemical found in the leaves of cycad plants
Animals:
- Dimethylnitrosamine is produced in the stomach when nitrite is consumed
- Found in some hams, sausages and meats
● compare the causes, processes and effects of different types of mutation, including but
not limited to:
- point mutation
- chromosomal mutation
Mutation
Inquiry question: How does mutation introduce new alleles into a population?
Students:
● explain how a range of mutagens operate, including but not limited to:
- electromagnetic radiation sources
- Chemicals
- naturally occurring mutagens
● compare the causes, processes and effects of different types of mutation, including but
not limited to:
- point mutation
- chromosomal mutation
● distinguish between somatic mutations and germ-line mutations and their effect on an
organism (ACSBL082, ACSBL083)
● assess the significance of ‘coding’ and ‘non-coding’ DNA segments in the process of
mutation (ACSBL078)
● investigate the causes of genetic variation relating to the processes of fertilisation,
meiosis and mutation (ACSBL078)
● evaluate the effect of mutation, gene flow and genetic drift on the gene pool of
populations (ACSBL091, ACSBL092)
Mutation: a mutation refers to a change in the base sequence of an organism's DNA
Mutations can be caused by:
- Mutagen: environmental agent which damages the DNA
- Cellular error: cell makes a mistake during cell division
● explain how a range of mutagens operate, including but not limited to:
- electromagnetic radiation sources
- Chemicals
- naturally occurring mutagens
Mutagen: an agent which can change the structure of DNA causing a mutation
Chemical mutagen: cause a change in DNA that alters the function of proteins and as a result the cell
will not function properly
- Eg. ingested chemicals: alcohol, tobacco, cleaning products
- Effects: results in the assertion of incorrect nucleotides opposite to their complementary
bases, termed mispairing
- Results in non functional proteins
Biological mutagens: Microbes: fungi, viruses, some bacteria
- Effects: mutagenic microbes are able to insert their own base sequence into DNA of the hosty
and change the functioning of genes and trigger cancer
- Can cause inflammation, reduce repair systems, increasing mutations
Physical mutagens: heat, ionizing radiation
- Effects: heat and ionising radiation can carry enough energy to breach chemical bonds in the
DNA
- Cause skin cancer and can prevent replication and transcription
, Electromagnetic Radiation:
- Waves which carry electromagnetic energy
- Only ones with short wavelength and high energy waves can cause mutation
- UV light, x-rays and gamma rays
Sources of
electromagnetic
radiation:
1. The sun is
the biggest source of EM radiation in everyday life (UV light)
2. Radioactive elements such as uranium-236.
- Release gamma rays as they decay
- Mde by chemistry lads or nuclear bombs
3. Medical imaging machines
- X ray machines, PET scanners
Chemicals:
- Different chemicals cause mutations in different ways
- Chemical is accidentally incorporated into DNA instead of proper nucleotides eg. 5-BDU
- Chemical inserts itself into the DNA eg actinomycin D
- Chemical makes gaps in the DNA eg. dimethyl sulfate
Naturally occurring mutagens:
- Mutagenic chemicals which specifically come from microbes, plants and animals
Microbe:
- Mycotoxins are poisonous chemicals produced by fungi
- Most likely to encounter
- Eg. aflatoxin B1 - inserts itself into DNA and distorts it
Plants:
- Cysain is a mutagenic chemical found in the leaves of cycad plants
Animals:
- Dimethylnitrosamine is produced in the stomach when nitrite is consumed
- Found in some hams, sausages and meats
● compare the causes, processes and effects of different types of mutation, including but
not limited to:
- point mutation
- chromosomal mutation
