Selective breeding and genetic modification Flashcards
What is selective breeding?
When humans choose individuals within a species to breed, in order that the offspring might have specific characteristics
What are the stages in selective breeding?
Two individuals with the required characteristic are chosen. They are then bred. Offspring which have inherited the characteristic are then bred. This is repeated over many generations until all offspring have the required characteristic
What is a use of selective breeding?
In agriculture (farming) e.g. to produce larger crops and animals. Also domesticating animals
What is tissue culturing of plants used for?
Producing cloned (genetically identical) plants
What are the stages in tissue culturing?
- Tissue is taken from a parent plant (called an explant)
- tissue is transferred to an agar plate containing nutrients and hormones which promote growth
- Plantlets are transferred into soil to grow into plants
What is genetic engineering?
The process of inserting a gene of one organism into another organism’s genome
During genetic engineering, what are restriction enzymes?
They cut the DNA at a certain point to remove a certain gene
During genetic engineering, what is the role of ligase?
Ligase in an enzyme which joins DNA containing the new gene together
During genetic engineering, what is a sticky ends?
When the DNA is cut by restriction enzymes, a staggered cut is made, leaving sticky ends
During genetic engineering, what is a vector?
The vector is the DNA molecule which carries the DNA into a cell to be replicated. E.g. plasmid DNA of a bacterium
What are some of the uses of genetic engineering?
E.g. creating insect resistant crops, creating crops which are pesticide resistant, creating food with a higher nutritional content, creating insulin for diabetics
What are some of the risks of genetic engineering?
Loss of biodiversity, concerns that species may escape into the environment, concerns that genes may be passed into other species. Some people object on ethical or religious grounds, believing that genetic engineering is ‘playing god’
What are some of the risks of selective breeding?
Loss of genetic diversity within a population, meaning it is more susceptible to diseases. Interbreeding over successive generations can cause health problems, e.g. breathing or heart problems in pedigree dogs
