Topic 4: Natural Selection and Genetic Modification Flashcards
What is selective breeding?
The process by which humans artificially select organisms with desirable characteristics and breed them to produce offspring with similar phenotypes
What are the main steps involved in selective breeding?
Identify a desired characteristic, select parent organisms that show the desired traits and breed them together, select offspring with the desired traits and breed them together and the process repeated unto all offspring have the desired traits
What is the main advantage of selective breeding?
Creates organisms with desirable features
Where else is selective breeding useful?
In medical research and in sports
What are the disadvantages of selective breeding?
Reduction in the gene pool, inbreeding results in genetic disorders, development of other physical problems and potential to unknowingly select harmful recessive alleles
How can plants be cloned?
Taking plant cutting and tissue culture
What is tissue culture?
A method of growing living tissue in a suitable medium
How are plant are grown using tissue culture?
Select a plant that shows desired characteristics, cut multiple small sample pieces from meristem tissue, grow in a Petri dish containing growth medium and transfer to compost for further growth
What must be ensured when preparing tissue cultures?
Ensure aseptic conditions to prevent contamination by microorganisms
What does the growth medium contain?
Nutrients and growth hormones
What are the advantages of growing plants by tissue culture?
Fast and simple process, requires little space, enables the growths of many plant clones with sales desirable characteristics and useful in the preservation of endangered plant species
What are the disadvantages of growing plants by tissue culture?
Reduction in the gene pool, plant clones often have low survival rate and could unknowingly increase the presence of harmful recessive alleles
Why is animal tissue culturing useful?
Useful in the preparation of tissue samples for medical research and enables the investigation of how different factors may affect a specific animal tissue, without harming the animal itself
How does animal tissue culture are prepared?
Extract a sample of tissue from an animal, use enzymes to separate cells within the sample, grow in a culture vessel containing growth medium and once grown, store the sample
What is genetic engineering?
The modification of the genome of an organism by the insertion of a desired gene from another organism and enables the formation of an organism with beneficial characteristics
What happens in the process if genetic engineering?
DNA is cut at specific base sequence by restriction enzymes to create sticky ends, vector DNA cut using the same restriction enzymes to create complementary sticky ends, ligaments enzymes join the sticky ends of the DNA and vector DNA forming recombination DNA and recombination DNA mixed with and ‘taken up’ by target cells
What is a vector?
A structure that delivers the desired gene into the recipient cell
What are the benefits of genetic engineering?
Increased crop yields for growing population, using in medicine and GM crops produce scarce resources
What are the risks of genetic engineering?
Long-term effects of consumption of GM crops unknown, negative environmental impacts, late-onset health problems in GM animals and GM seeds are expensive
What is Bacillus thuringiensis (Bt)?
Insect larvae are harmful to crops and Bt is a bacterium which secretes a toxin that kills insect larvae
How is genetic engineering used to protect crops against insects?
The gene for toxin production in Bt can be isolated and inserted into the DNA of crops and Bt crop now secrete the toxin which kills any insect larvae that feed on it
