Selective Breeding, Genetic Modification, Cloning Flashcards
Describe how the process of micropropagation can be used to produce plants with desirable characteristics (3)
- Small pieces of tissues called explants are removed from a plant using a scalpel and grown in vitro
- Sterilised apparatus are used (to reduce the risk of contamination by microorganisms) and grown on a sterile agar medium that contains nutrients, mineral ions and plant hormones
- When the explants have grown roots, they are transferred to a greenhouse, which provides light and a humid environment to prevent water loss from the young plant
What are the advantages of using micropropagation rather than using seeds to produce plants with desirable characteristics? (4)
- Quick
- Large yield
- Can be produced any time of year
- No genetic variation
Describe the stages used to produce a cloned mammal (4)
- The egg cell is enucleated
- A body cell nucleus from an adult with desirable characteristics is inserted into the egg
- There is an electricity shock that fuses the two cells
- Cell division occurs and an embryo is developed in the womb of a surrogate mother
What is a cloned organism?
- Genetically identical
Describe the process of selective breeding
- Humans select organisms with desired features
- They breed the organisms to produce offspring with the desired traits
- This process is repeated across several generations
What advantages of using embryo cloning rather than using selective breeding? (4)
- Identical
- Faster process (no need to be repeated)
- More produced
- No need for two parents
Name the type of cell division that produces an embryo from an individual cell
- Mitosis
Name the small circle of DNA that is genetically modified in bacteria
- Plasmid
Name two enzymes that are used to genetically modify the DNA of bacteria (2)
- Ligase
- Restriction endonuclease
Describe the stages by which a bacterium can be genetically modified to produce large amounts of a named human protein (5)
- A restriction enzyme cuts out a section of human DNA
- The same restriction enzyme cuts out a section of the plasmid
- The isolated gene is inserted into the plasmid that has been opened up using ligase
- This creates a recombinant plasmid that is then inserted into a bacteria
- The newly formed transgenic bacteria will produce the protein coded for by the newly inserted gene
What is a transgenic organism?
- Has had genetic material from a different species transferred into its cell
What is recombinant DNA?
- DNA made by genetic engineering by combining DNA from two species of organisms
What is a vector?
- A structure that can be used to transfer genes in genetic engineering
- e.g. plasmid, virus
How does natural selection differ from selective breeding? (4)
- Humans are not involved
- Survival of the fittest
- A much slower process
- Role of chance
What does enucleated mean?
- Removal of the nucleus
What are the advantages of using organs produced by therapeutic cloning compared to using donated organs?
- No need to match
- No shortage of organs
- Free from infection
What are some of the uses of transgenic organisms? (3)
- Insulin production
- Gene therapy
- Herbicide resistance
What is meant by the term genetic modification and suggest why a farmer might want to grow a GM crop? (2)
- Transfer of a desired gene into an organism using a vector
- Resistance to pest/diseases/increase food production
Suggest how the air inlet helps the genetically modified bacteria to grow in a fermenter
- Provides oxygen for aerobic respiration
If the pH probe stops working, the pH in the fermenter becomes more acidic. Describe and explain how this affects the production of human insulin. (4)
- Less insulin production
- Unable to kill bacteria
- The enzymes are not at their optimum pH
- Active site could be denatured
