Module 3G Flashcards
Describe the process of selective breeding?
1) Organisms with genes that code for desired characteristics are selected.
2) The desired organisms are cross bred.
3) Suitable offspring are selected and they are also cross bred.
4) This process continues over many generations.
Explain how selective breeding can contribute to improved agricultural yields?
Farmers will perhaps select cows and bulls that clearly have the gene for being large and fat and cross breed them. They will then cross breed their offspring so that they begin to have a population of large cows, this will over time increase the meat production yield.
How can selective breeding result in inbreeding and why is this a disadvantage?
The farmer is cross breeding organisms that are closely related which will reduce the gene pool. Closely related organisms often have similar genes. This can cause health issues.
Explain exactly how inbreeding causes health risks.
There is an accumulation of recessive alleles and as most genetic disorders are coded for by recessive alleles it is much more likely that the organisms will have genetic disorders.
What kind of variation is reduced when organisms are selectively bred and how can this be a problem?
Genetic variation and if a disease effects one organism it is likely to wipe out the entire population.
What is genetic engineering?
It is when a gene is transferred into a different organism in order to produce useful biological products.
What is an advantage of genetic engineering?
Organisms with desired features are produced rapidly.
What is a disadvantage of genetic engineering?
Inserted genes could have unexpected harmful effects.
What is the process of genetic engineering?
1) The gene responsible for the desired characteristic is selected.
2) The gene is cut from the DNA using restriction endonuclease which is an enzyme and the gene is, therefore isolated.
3) The isolated gene is inserted into the DNA of another organism.
4) This organism will now replicate.
How has genetic engineering helped to combat ‘Vitamin A’ deficiency.
The gene responsible for beta carotene is selected from a carrot plant. It is isolated from the carrot plant. It is inserted into the rice plant. The rice plant grows with the beta carotene gene in it. The rice is eaten and humans can convert the beta carotene into Vitamin A.
Explain how genetic engineering is used to help the production of human insulin.
The gene that is responsible for the production of human insulin is selected. It is the isolated from the DNA of a human. It is inserted into a bacteria organism. It is cultured in a fermenter. The human insulin is then extracted as the bacteria multiply and produce it.
Discuss the ethical issues involved in genetic modification?
Some people deem it selfish to genetically modify animals for human needs. There is a worry it could create a genetic underclass. We are unaware of the evolutionary consequences.
What is gene therapy?
It is when genes are altered in order to combat genetic disorders.
Describe gene therapy in terms of body cells. (USE CYSTIC FIBROSIS AS AN EXAMPLE)
The cells in the body will receive the gene therapy. Cystic fibrosis affects the lungs so it is likely the cells in the lungs will undergo the therapy as they are directly affected.
If Tim had gene therapy on his lung cells when he was younger, how come his son has cystic fibrosis.
The gene therapy did nothing to alter the genes in the gametes.
