B7 Genetic Engineering/Fossils Flashcards
3 reasons for selective breeding
Animals that produce more meat or milk.
Crops with disease resistance
Crops that produce larger fruit/yield
Process involved in selective breeding
From your stock choose the ones which have the characteristics you need
Breed them together
Continue this process over several generations.
The desirable trait will just get stronger
What is a major disadvantage of selective breeding
Reduces the gene pool- reducing number of alleles in a population.
Due to the farmer breeding the best organisms which are all closely related.
If a new disease appears that kills one then they will be very suscpetible to it since there is little to no variation in the species.
Definition
Genetic engineering
Transferring a gene responsible for a desirable characteristic from one organisms genome into another organism so that it also has the desired characteristic
An example of a genetically engineered organism and steps
A useful gene is isolated(cut) from an organisms genome using enzymes and placed in a vector
Vector is either a virus or a bacterial plasmid
Then useufl gene is inserted to cells.
For example Bacteri that can prodcue human insulin to treat diabetes
2 Pro/Cons of GM crops
Pro-Increase Yield/Can fulfill nutrients that people are missing
Con-Reduce farmland biodiveristy by reducing number of wildflowers and insects/Transplanted genes may get out to enviroment so weeds could become resistant to herbicide.
3 ways to make fossils
Explain each
Gradual Replacement by minerals- Bones and shells dont decay easily so are replaced by minerals as they decay so they form a rock like substance shaped like the organism.
Preservation- Amber is a clear yellow stone where there is no oxygen or moisture so decay microbes cant survive. Glaciers are too cold for decay to occur and peat bogs are too acidic for decay to occur.
Casts/Impressions- Fossils are formed when an organism is buried in a soft material like clay. The clay hardens around the shape leaving a cast.
Definition
Fossil
Fossils are the remains of organisms from many thousands of years ago which are found in rocks. They provide the evidence that organisms lived ages ago
What are the 2 methods of plant cloning
Tissue culture- Plant cells are place in medium containing hormones. They grow into new plants- clones of the parent plant. Can be grown all year round.
Cuttings- Gardeners take cuttings from parent plants and then plant them to produce genetically identical copies. Plants can be produced quickly and cheaply.
How to clone animals
Embryo transplants.
Take a sperm cell and implant it into an embryo then divide the embryo multiple times. So that all offspring are gentically identical.
Describe the process of adult cell cloning
A nucleus is removed from an adult body cell
This nucleus is inserted into an egg cell that has had its nucleus removed
Egg cell is stimulated to divide by an electric shock
Embryo is developed and implanted into a surrogate mother
2Pros/Cons of cloning
Pro-Preserve endangered species/Higher yield
Cons-Reduced gene pool/Some may not be as healthy
Why are more bacteria becoming resistant
As people do not take the full course of antibiotics. The bacteria rapidly reproduce and the new strain is resistant. They are more likely to survive so reproduce more. This means that the new strain is ressitant so a new antibiotic must be devloped.
