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
How have potatoes been genetically modified, and why?
- Modified to make more starch & be pest resistant
- Larger crop yield = more money for farmer
How have soybeans been genetically modified, and why?
- Modified to produce a healthier balance of fatty acids
- More nutritious for consumer & farmer can sell for more money
Investigating variety in animals
Scientists use groups of animals that are genetically very similar
Investigating variety in humans
- Use identical twins that have been adopted by different families
- Scientists measure features eg height, weight & IQ
- They find that some differences are mainly due to genetics & some are largely due to the enviro
Investigating variety in plants
Put identical plants in different situations to see how the environment affects their appearance
Limitations of selective breeding?
- Greatly reduces number of alleles in the population which reduces variety
- When conditions change the lack of variation means none of the plants & animals can cope so that population will die out
- Problem of ‘inbreeding’ results in little variation so some breeds are particularly prone to certain diseases
Process of genetic engineering (in animals)
- Useful gene cut from one organism’s genome using ENZYMES and inserted into a VECTOR.
- Vector(virus/bacterial plasmid) inserts useful gene into CELL of organism
- Genes are transferred to the cells at an early stage of development
- As the organism grows it develops with the new, desired characteristic from the other organism
Risks of adult cell cloning
- Many people fear it could lead to cloning of human babies
- Produces lots of plants or animals with identical genes = no variation (pop is less able to survive as envrio changes)
Stem & leaf cuttings
- Many plants clone themselves naturally
- Used by farmers and gardeners for hundreds of years
- Cuttings can be taken from almost any part of a plant; roots, stem, and leaves, then it is planted in damp compost.
The process of natural selection
- Mutation in genes leads to variation in a population
- Some organisms better adapted
- These organisms survive
- They breed
- The next generation is better adapted
- This can lead to evolution
Tissue culture
- It allows you to make thousands of clones of the parent plant.
- Each cell scraped from the parent has the potential to grow into a clone
- Using a mix of nutrients and hormones, tiny plantlets can be produced very quickly
Types of GM crops
- Potatoes
- Soybeans
- Rice
- Grasses
What are some desired characteristics?
- Disease resistance
- Increased food production in animals & plants
- Domestic dogs with gentle nature
- Heavily scented flowers
What is a clone?
An individual that has been produced asexually and is genetically identical to the parent
What is evolution?
The process of change over time
What is genetic engineering?
The deliberate modification of the characteristics of an organism by manipulating its genetic material.
What is natural selection?
The process whereby organisms better adapted to their environment tend to survive and produce more offspring
What is selective breeding?
Living organisms with desired traits are bread so as to produce such traits in offspring
Put the classifications in order?
Kingdom,Phylum,class,order,family,genus,species
