Artificial clonging in animals - two possible ways
Only embryonic cells are naturally capable of going through stages to create a new individual. These are known as TOTIPOTENT STEM CELLS. These can switch on any genes present in the genome.
Splitting embryos artificial identical twins
- Cells from developing embryo are separated out.
- Each one then creastes a seperate individual.
Nuclear transfer - using enucleated eggs
- Differentiated cell from an adult can taken and its nucleus placed in an egg cell that has had its nucleus removed.
- Egg then goes through stages of development using information from the inserted nucleus.
- To make the nucleus and egg cell join, electricity in the form of electro fission is used.
Advantages- high value animals can be cloned in large numbers, rare animals can be cloned to preserve species, genetically modified animals with a specific role can be reproduced quickly.
Disadvantages - welfare issues are usually an issue, species are less liekly to be able to adapt to their environment, its unclear whether cloned animals using genetic material from adult cells are healthy long term.
What is non reproductive cloning? - Generating cells and tissues to replace those that are damaged.
- Being genetically identical to the patients own cells, there is less chance of the tissues being rejected.
- Could result in people not having to wait for donor organs, and using the cloned cells are less dangerous than a major operation.
Possibilities for non productive cloning -
- regeneration of heart muscle after heart attack, repair nervous tissue, repairing spinal cord after paralysis.
Biotechnology affects our lives through -
Healthcare and Medical proccesses - production of drugs by microorganisms. Agriculture - micropropogation of plants and GM plants. Industry - to create enzymes to catalyse reactions.
The use of microorganisms in biotechnology - the use of bacteria and fungi in various processes is widespread becuase microorganisms:
- grow rapidly in favourable conditions
- often produce proteins or chemicals that are given out into surroundings that can be harvested
- can be genetically engineered to produce specific products
- grow well at low temperatues, little energy costs, more sustainable
- their growth is not dependable on the climate
- genertaes purer products that that created by chemical proccesses
- nutrients produced are often not toxic to humans.
The Growth Curve
The standard Growth Curve
Lag Phase - organisms are adjusting to their surroundings. Activating enzymes, population is not growing. Legnth of this depends on growing conditions. Log Phase - population size doubles each generation as space and nutrients are available for reproduction. Legnth dependson ability to take up nutrietns and reproduce. Stationary phase - nutrient levels decrease and waste products build up. Individuals die at same rate that individuals are generated. Death phase - nutrient exhaustion and increased levels of toxic waste products leads to death rate increase above reproduction rate.