Selective Breeding and Genetic Engineering B6 Flashcards
What is selective breeding?
Selective breeding is the process of finding plants or animals with the best characteristics and breeding them. The process is repeated over many generations until the desired characteristics are present in all offspring.
Describe the process of selective breeding
First, find variation in the species. Pick the desired characteristics you want. Choose parents that show these characteristics from a mixed population. Then breed them together. Choose the best offspring with the desired characteristics to produce the next generation. Repeat the process continuously over many generations, until all offspring show the desired characteristics.
What are the disadvantages to selective breeding?
Selective breeding creates many similar plants and animals which reduces variation.
Inbreeding, it can lead to genetic diseases and defects in the organisms.
What are the benefits of selective breeding?
New varieties may be economically beneficial, e.g. producing better quality food. Animals that can’t cause harm can be selected, e.g. cattle without horns.
What are the risks of selective breeding?
Leads to reduction in variation which can cause disease or attacks by specific insects. It can create physical problems, e.g. large dogs can have faulty hips due to not being formed correctly.
What is genetic engineering?
Genetic engineering is the altering of a genome of an organism (by adding a gene or genes from a different organism) to result in a desired characteristic.
What are the benefits of GM foods?
Benefits of genetically modified foods could be more nutritious crops, crops can grow in harsh environments, better flavoured food, food with longer shelf life and higher crop yields.
What are the risks of GM foods?
Some risks of genetically modified foods include once out in the wild it is impossible to recall genetically modified organisms. Genetically modified organisms may breed with other non-GM organisms passing on foreign genes into the wild. We do not know the long-term effects of eating GM food, they may harm the consumer.
Describe the process of genetic engineering.
A strand of DNA is taken from the organism that has the useful characteristic. The gene for the useful characteristic is isolated and cut from the DNA using restriction enzymes, some enzymes produce DNA with short, single stranded pieces at the ends - these are called sticky ends. The desired gene is ‘pasted’ into the DNA of the organism that requires the useful characteristic using ligase enzymes.
What is a plasmid vector?
A plasmid vector is a small loop of DNA often containing ‘marker’ genes for antibiotics resistance. They also move genes from one organism to another.
What are vectors used for?
Vectors are used to insert DNA into other organisms.
