B14 Flashcards
Adult cell cloning process
- Nucleus is removed from an unfertilised egg
- At the same time, nucleus is taken from an adult body cell
- Nucleus from adult is inserted into empty egg cell
- New egg cell is given a tiny electric shock, which stimulates it to start dividing to form embryo cells
- When embryo has developed into balls of cells, it is inserted into the womb to develop
Benefits of adult cell cloning
- Animals that have been genetically engineered to produce useful proteins in milk can be cloned = good way of producing large numbers of medically useful animals
- Help save animals from extinction / bring back animals that have died out
- Clone pets
Benefits of genetic technologies
- Potential to cure inherited disorders
- Genetically identical MO’s can make proteins humans need in large quantities & pure form eg insulin
- Scientists can genetically modify mice to mimic human diseases
- Agricultural uses eg improved growth rate
Combined causes of variety
Due to BOTH genes & environment
Concerns of genetic technologies
- Unsure of long-term effects
- Concerns about the effect of eating GM foods on human health
- Fears about human engineering & the prospect of ‘designer babies’
Embryo transplant (animal cloning)
- Give fertility hormones to a top-quality cow so she produces more eggs
- Fertilise these eggs using sperm from a really good bull = often done inside the cow
- Embryos produced are gently washed out of the uterus
- Sometimes eggs are collected & you add sperm in the lab to produce the embryos
Environmental variation
Differences between organisms caused by environmental factors
Examples of combined causes of variety
Height
Weight
Skin colour
Hair colour
Examples of environmental variation
- Scars
- language and accent
- flower colour in hydrangeas as these plants produce blue flowers in acidic soil and pink flowers in alkaline flowers
Examples of genetic variation
Eye colour
Blood group
Inherited disorders
Genetic engineering in plants
- Using the Ti-plasmid from Agrobacterium, and a natural insecticide gene isolated from another organism, recombinant plants have been produced which are resistant to insects
- In plants, desired genes are inserted into meristem cells which then produce identical clones of the GM plant
Genetic variation
Differences among individuals in the composition of their genes or other DNA segments
How does selective breeding work?
- From your existing stock, select those with the characteristics you want and breed them together.
- Then select the best offspring and breed them together.
- Continue this over several generations and the characteristic becomes stronger and stronger
How has Rice been genetically modified, and why?
- Modified to survive being covered by water for up to 3 weeks
- Larger yields & are not affected by flooding
How have grasses been genetically modified, and why?
- Modified to absorb & break down explosive residues in the soil
- Healthier & safer crops