Zusammenfassung der Ressource
Evolution
- Evolution
- plants - make own food
- animals move & can't make own food
- microorganism - single-celled
- Natural Selection
- variation - genes
- better adapted = better chance of survival = reproduce - passed onto next generation
- Mutations - change in DNA
- could be beneficial - useful characteristic = better chance of survival/reproducing
- accumulate e.g bacteria - resistant to antibiotics
- Darwin - not all agreed
- religious beliefs - God
- Lamarck - acquired characteristics = passed onto offspring
- Genetic Engineering
- Enzymes - cut and paste Genes
- useful gene - 'cut' - using enzymes
- enzymes - cut another chromosome & insert useful gene
- bacteria can produce human insulin
- Genes - Transferred into Plants & Animals
- transfer useful genes at early stage = useful characterictics
- Genetically modified crops - resistant to viruses, insects, herbicides
- Genetic disorders - inserting working genes - gene therapy
- affect no. of weeds/flowers, insects - reducing farmer biodiversity
- transplanted genes - into natural environment - herbicide resistance picked up weed = new 'superweed'
- increase yield
- lack of nutrients - engineering could add that nutrient
- Cloning
- Cuttings & Tissue Culture
- take cuttings from good parent plants = genetically identical copies - quick & cheap
- tissue culture - few plants cells put in growth medium with hormones - grow into new plants
- clones - quick, little space, grown all year
- Animal Clones - Embryo Transplants
- sperm & egg cells - best cow & bull - artificially fertilise - embryo split = clones
cloned embryos - implanted into other cows
- Adult Cell Cloning (Dolly)
- removing genetic material (nucleus) from egg cell - complete
set of chromosomes from adult body cell inserted into empty cell
- electric shock - to split up
- implanted into adult female
- 'reduced gene pool' - no resistance to disease
- study - more understanding of embryo - ageing & age-related disorders
- endangered species
- may not be as healthy - Dolly had arthritis - occurs in older sheep anyway