What is the role of restriction enzymes in genetic modification?
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What is the role of restriction enzymes in genetic modification?
Restriction enzymes are used in genetic modification to cut specific DNA sequences, allowing for the isolation and manipulation of genes. These enzymes recognise and cut DNA at specific nucleotide sequences, resulting in fragments with ends known as "sticky ends."
How does DNA ligase contribute to genetic modification?
DNA ligase plays a critical role in genetic modification by forming the bonds between adjacent DNA fragments. This enzyme seals the gaps in DNA molecules, joining the fragments together to form a continuous strand of DNA.
Name the two enzymes used to cut DNA and join DNA for genetic engineering.
The two enzymes are restriction enzyme and DNA ligase.
Define genetic modification.
Genetic modification refers to the process by which scientists alter genetic material by introducing new genes or altering existing ones to give desirable characteristics.
What is recombinant DNA?
Recombinant DNA is DNA taken from two different organisms combined into one strand.
What is the role of plasmids and viruses in genetic modification?
Plasmids and viruses help move DNA between cells. Plasmids work in bacteria and yeast, while viruses work in human cells or bacteria.
Define the term vector in genetic modification.
A vector takes up pieces of recombinant DNA and then inserts this DNA into other cells.
How do plasmids and viruses transfer DNA?
They carry DNA into cells.
Plasmids carry DNA into bacteria or yeast by passing into the cell through the cell membrane.
Viruses carry DNA into human cells or bacteria. Viruses can inject DNA through the membrane into bacterial the cell without entering the cell itself.
How do bacteria reproduce recombinant plasmids?
Bacteria make copies of the modified recombinant DNA inside them as they reproduce by asexual reproduction. This passes on the recombinant DNA to their offspring.
Why are genetically engineered bacteria useful in the production of specific proteins e.g. insulin?
Once bacteria have been genetically modified to contain the correct gene, they are able to reproduce quickly and synthesise large quantities of the specific protein required.
How is the gene for human insulin extracted from human DNA?
The gene for human insulin is extracted from human DNA using restriction enzymes which cut the DNA at each end of the required gene sequence.
True or False?
The human gene for insulin is cut out with the same restriction enzyme that is used to cut the vector plasmid during genetic modification.
True.
The same restriction enzyme is used to cut the human gene and the plasmid to make sure they have the same complementary DNA bases on their sticky ends to allow the sticky ends to bond together.
What method is used to mass produce insulin from genetically modified bacteria?
In order to mass produce insulin from genetically modified bacteria the bacteria are grown in fermenters and the insulin product is extracted and purified.
True or False?
When genetically modified bacteria reproduce they do not pass on the genetically modified plasmid to their offspring.
False.
All the DNA in the bacteria is copied and passed onto offspring during asexual reproduction, including any recombinant DNA.
Why is an industrial fermenter used to produce human insulin in large quantities?
The conditions inside a fermenter can be regulated to ensure optimum growth conditions for the bacteria. This will maximise the yield of insulin that is collected.
What are GM crops?
GM crops, or genetically modified crops, are crop plants that have been genetically altered with DNA from another organism to possess certain desirable traits, such as insect resistance.
What is the purpose of modifying crop plants to be herbicide-resistant?
Modifying crop plants to be herbicide-resistant ensures that when herbicide is used, only weeds are killed, not the crop plants.
What environmental concerns are associated with GM crops?
GM crops raise concerns about their impact on wildflower and insect populations due to possible transfer of genetic modifications through breeding and increased herbicide/pesticide use. There are concerns that consuming GM crops may be a danger to human health, e.g. unknown allergies.
True or False?
Concerns about the health effects of consuming GM crops have been fully explored.
False.
Some feel that the health effects of consuming GM crops have not been thoroughly investigated.
What is a benefit of genetically modified crops to the farmer?
Growing genetically modified crops may have many benefits to the farmer including:
Increased crop yield.
Decreased costs.
Reduction in the requirement for pesticides, herbicides or fertilisers.
What is the definition of a 'transgenic organism'?
A transgenic organism contains DNA from more than one species due to genetic modification.
True or False?
Transgenic means the transfer of genetic material between individuals of a species.
False.
Transgenic means the transfer of genetic material from one species to a different species.