Module 6: Genetic Change Flashcards
What are physical muatgens?
Heat and ionising radiation
What is ionising radiation?
Radiation that has enough energy to break chemical bonds in DNA
What does ionising radiation cause in DNA?
Deletion or partial chromosome loss
What is base excision repair?
When damaged or incorrect base is removed and replaced
What is mismatch repair?
When DNA polymerase carries out ‘spell check’ for accuracy of replication
What is point muation?
A single nucleotide variation
What does point mutation usually result in?
Base substitution but some result in frameshift
What is an example of point mutation?
Sickle cell gene point mutation which causes sickle cell aneamia
What is frameshift mutation?
Point mutation that involves the insertion or deletion of a nucleotide
What does frameshift mutation result in?
A whole sequence of incorrect amino acids
What is a nonsense mutation?
Change in amino acids to a stop codon
What is a missense mutation?
Change in an amino acid
What is a silent mutation?
Change in DNA sequence that does not cause change in amino acids
What is chromosomal mutation?
Large scale changes where the overall structure or number of chromosomes is changed
What are the four types of chromosomal mutation?
Deletion
Duplication
Inversion
Translocation
What is chromosomal deletion?
When a section of DNA is removed and not replaced
What is chromosomal duplication?
Portion of DNA is duplicated and inserted
What is chromosomal inversion?
DNA is removed and turned 180 degrees and reinserted
What is chromosomal translocation?
DNA is moved from one chromosome to another
What is aneuploidy?
When one or more extra copies of an entire chromosome are made or are missing
What are somatic mutations?
Mutations that occur in somatic cells which are non-reproductive cells
How does a somatic mutation occur?
Due to replication error
What cells does somatic mutations effect?
Daughter cells of somatic cells
What are germline mutations?
Mutations that occur in the germline cells which are gametes
What cells does germline mutations effect?
Passed onto offspring and effects all cells
What is genetic drift?
Change in allele frequency due to chance
What is an example of when genetic drift may occur?
When a natural disaster may wipe out some organisms in an area
How does genetic drift impact allele frequency?
The allele frequency of survivors will increase
What is gene flow?
The change of allele frequency from the movement of individuals
What 4 factors affect allele frequency?
Selective pressure, sexual selection, mutation and gene flow
What is the bottleneck effect?
A large decrease of organisms due to natural disaster
What is the founder effect?
When individuals become geographically isolated
How does population size impact genetic drift?
The smaller the population the greater the impact is
What is biotechnology?
The use of biological materials as tools
How long has biotechnology existed for?
Many thousands of years
What is an example of ancient biotechnology?
Agriculture and selecting the seeds from the best crops and hybrid vigour
What is hybrid vigour?
Cross breeding resulted in stronger and healthier offspring
What is an example of cross breeding?
A change in grains characteristics to make them more suitable
Einkorn + Emmer = Durum
What is an example of classical biotechnology?
Fermentation using biological materials such as cells and cell products to achive goals
What is modern biotechnology?
It is mainly genetic engineering and manipulation of genetic material
What are the three steps for genetic engineering?
Cut - using enzymes to snip out a gene
Copy - use PCR to produce more of it
Paste - insert the gene into bacteria
What is recombined DNA?
DNA made up of DNA from multiple genomes
What are GMOs?
Organisms that have DNA from more than one species
What are transgenic species?
Are GMOs that can pass on their genome
What is DNA splicing?
Cutting out the genes using restriction enzymes
What are restriction enzymes?
Molecular scissors snipping DNA into smaller parts
What is used to recombine DNA?
DNA ligase enzyme is used to join DNA pieces together
How does DNA profiling work?
Amplification of short tandem repeats, STRs and then comparing the base sequences to determine relatedness
What are three examples of agricultural biotechnology?
Artificial insemination and pollination, in vitro fertilisation and embryo transfer and cloning
What are the advantages of agricultural biotechnology?
Increased yield, quality and nutrients in food
What are the negatives of agricultural biotechnology?
Loss of genetic diversity and fair and equitable sharing of resources
What is conservation biotechnology?
Artificial insemination used for conservation in the wild and zoos
What is gene therapy?
Is the injection of normal genes into individuals who are lacking this gene
What are the benefits of in vitro fertilisation?
Allows infertile parents to have children and eliminates the risk of children being born with inherited genetic diseases
What is bioethics?
The study and investigation of decisions in medicine and science
What do bioethicists do?
They compare risks and benefits of things against the potential consequences of not using it
What must bioethics take into consideration?
Beliefs, values and culture
What is CRISPER?
An enzyme with the role to chop up DNA of invading viruses
Why is the discovery of CRISPER so important?
Genes can now be spliced and inserted with pinpoint accuracy
How does biotechnology impact biodiversity?
In the short term increases biodiversity with new alleles and in the long term decreases biodiversity
What is selective breeding?
Mating male and female with desirable characteristics
What are the positives of selective breeding?
Offspring are fertile
What are the negatives of selective breeding?
Time consuming and costly
What is artificial insemination?
Collecting of sperm from chosen males and artificially introducing it to the female
What are the positives of artificial insemination?
Sperm can be stored frozen for a long time, it is cost effective, reduces risk of injury and offspring can still be produced many years later
What is a negative of artificial insemination?
Reduction of genetic diversity
What are the negatives of IVF?
Genetic diversity is reduced, genes of infertility can now be passed on
What is artificial pollination?
The stamen is removed and pollen is dusted onto the stigma
What is gene cloning?
When a gene is removed and inserted into the DNA of another organism
What are the four steps to gene cloning?
- Gene is cut from source restriction enzymes
- Gene is pasted into vector DNA or plasmid known as ligase
- Plasmid is introduced to host cell by transformation
- Host cell now makes copies of the vector DNA
How many attempts did it take to make dolly?
Around 280
What is an example of whole organism cloning that is used worldwide?
Seedless grapes
What is required for whole organism cloning?
Three animals:
- Nucleus doner
- Egg doner
- Surrogate mother
What are the ethical issues of whole organism cloning?
Animal welfare and that this technique could be used on humans
What is micro injection of DNA?
When DNA is directly injected into the nucleus of a single cell
What is biolistics?
Mechanically delivering DNA into cells by using a gene gun
What is transduction?
The delivery of DNA into a cell via a viral vector
What are BT cotton plants?
Cotton which contain a gene that produces a protein that kills caterpillars when ingested
Why is it called BT?
As it comes from the bacteria Bacillus thuringiensis
Why is BT cotton beneficial?
As caterpillars destroy millions of dollars worth of cotton each year and it reduces the need for pesticides
What are GM salmon?
Salmon that are genetically modified to grow faster and larger increasing yield
How are gametes with chromosomal mutation formed?
Meiosis
Failure of homologous chromosomes separating, an extra chromosome being left in one gamete and a chromosome missing from one gamete
What is the ligation of DNA?
The joining of 2 DNA molecules by the enzyme, DNA ligase
What is a possible outcome of artificial pollination on subsequent populations?
Improved plant production of fruit and seeds
When is artificial pollination usually used?
When there is a lack of pollinating insects due to wide spread use of insecticides or as the plants are grown in glasshouses
