6.2.1 Cloning and biotechnology Flashcards
Define clone.
An exact copy.
What is vegetative reproduction?
A natural form of asexual reproduction in which new plants develop via meristematic regions.
How can we produce natural clones of plants?
Vegetative propagation.
List some methods of vegetative propagation in plants.
-Rhizomes
-Runners
-Suckers
-Tubers
-bulbs
What are rhizomes?
Stem structures that grow horizontally underground away from the parent plant. They have nodes from which new shoots and roots can develop.
What are runners?
Similar to rhizomes only different is that they grow above the ground. New shoots and roots can either develop from nodes or at the end of the runner.
What are suckers?
Suckers are shoots that grow from sucker buds (undeveloped shoots) present on the shallow roots of a parent plant.
What are tubers?
large underground plant structures that act as a food store for the plant. They’re covered in ‘eyes’. Each eye is able to sprout and form a new plant.
What are bulbs?
Bulbs are also underground food stores used by some plants. New bulbs are able to develop from the original bunk and form new individual plants.
How do we produce a clone from a cutting?
1) Use a scalpel or sharp secateurs to take a cutting from the end of a stem on a parent plant.
2) Remove leaves from lower end of cutting and leave one at top.
3) Dip the lower end of the cutting into rooting powder.
4) Plant your cutting in a pot with a suitable growth medium e.g compost.
5) Provide with a warm and moist environment.
6) When your cutting has formed its own roots, transfer it somewhere else.
How can we produce artificial clones of plants?
-Micropropagation
-Tissue culture
What is the difference between micropropagation and tissue culture?
Tissue culture describes the starting process of growing plants on a nutrient-rich medium.
Micropropagation is when tissue culture is used to produce lots of cloned plants very quickly.
Explain the process of tissue culture.
1) Cells are taken from the original plant which is going to be cloned using sterile forceps.
2) The cells are sterilised. Bacteria and fungi compete for nutrients with plant cells which will decrease their growth rate.
3) The cells are transferred onto an agar medium which contains nutrients such as glucose and amino acids and growth hormones such as auxins.
4) A callus will form.
5) The callus is subdivided into smaller balls and moved into another growth culture containing shoot stimulating hormones.
6) Shoots will grow and then they will be transferred into a root stimulating hormone growth medium.
7) After roots have formed, the plantlets will be transferred out of the medium and planted into soil.
What is a callus?
A ball of undifferentiated cells.
Give some arguments FOR artificial plant cloning.
-Desirable genetic characteristics are always passed onto the clones. This does not always happen when plants reproduce sexually.
-Tissue culture allows plants to be reproduced in any season because the environment is controlled.
-Less space is required by tissue culture than It would be needed to produce the same number of plants by conventional growing methods.
-Produces lots of plants very quickly.
Give some arguments against artifical plant cloning.
-Undesirable genetic characteristics are always passed on to clones.
-Cloned plant populations have no genetic variability so a single disease could kill them all.
-Production costs of tissue culture are very high due to high energy use and training of skilled workers.
-Contamination by microorganisms during tissue culture can be disastrous and result in complete loss of the cultured plants.
Give an example of natural animal cloning.
Monozygotic twins (identical twins)
Name two types of artificial animal cloning.
-Artificial embryo twinning
-Somatic cell nuclear transfer
Explain how artificial embryo twinning works.
1) An egg cell is extracted from a female cow and fertilised in a Petri dish.
2) The fertilised egg is left to divide at least one forming an embryo.
3) The individual cells from the embryo are separated and each put into a separate Petri dish. Each cell divides and develops normally so an embryo forms in each Petri dish.
4) The embryos are then implanted into female cos which act as surrogate mothers.
5) The embryos continue to develop inside the surrogate cows and eventually offspring are born that are all genetically identical to each other.
What is the result of artificial embryo twinning?
All of the siblings created are genetically identical.
Explain how somatic cell nuclear transfer works.
1) A somatic cell is taken from sheep A. The nucleus is extracted and kept.
2) An oocyte (immature egg cell) is taken from sheep B. Its nucleus is removed to form an enucleated oocyte.
3) The nucleus from sheep A is inserted into the enucleated oocyte from sheep B.
4) The nucleus and the enucleated oocyte are fused together and stimulated to divide e.g by electrofusion. This produces an embryo.
5) The embryo is implanted into a surrogate mother and eventually a lamb is born that is the clone of sheep A.
Give some uses of animal cloning.
1) scientists use cloned animals for research purposes e.g they can test new drugs on cloned animals. They are all genetically identical so the variables that come from genetic differences are removed.
2) Cloning can be used to save endangered animals.
3) Cloning can be used in agriculture so farmers can increase the number of animals with desirable characteristics to breed from.
4) Animals that have been genetically modified to produce a useful substance that they wouldn’t normally produce can be cloned to produce lots of the same animals.
5) Cloning can be used to make embryonic stem cells which can become any cell type. This could help to replace damaged tissues. If replacing tissue is made from. The persons own embryonic stem cells, they won’t be rejected by the immune system.
What are some arguments FOR artificial animal cloning.
-Desirable characteristics are always passed on to clones.
-Infertile animals can be reproduced.
-Increasing the population of endangered species helps to preserve biodiversity.
-Animals can be cloned at any time and you don’t need to wait until breeding season.
-Can develop new treatments for diseases.
Arguments against artificial animal cloning.
-Very difficult, time consuming and expensive.
-No genetic variability in cloned populations- disease can wipe out a whole population.
-Clones may not live as long as nautral offspring.
-Using cloned embryos as a source of stem cells is controversial.
What is biotechnology?
Biotechnology is the industrial use of living organisms to:
-Produce useful products e.g foods and medicines
-Carry out useful services e.g sewage treatment, composting, bioremediation.
Why are microorganisms used to carry out biotechnological processes.
-simple growth requirements
-occupy very little space
-short-life cycle
-inexpensive
-rapid growth over small periods.
-Their ideal growth conditions are easily created
List some common processes that use biotechnology to produce useful products.
-Brewing and distilling
-Baking bread
-Cheesemaking
-Yoghurt production
-Penicillin production
-Insulin production
-Mycoprotein production
Explain how biotechnology is used in brewing.
Add yeast to a type of grain. The yeast respires anaerobically using the glucose from the grain and produces ethanol and CO2. When aerobic respiration produces ethanol (this is fermentation)
What is fermentation?
When aerobic respiration produces ethanol.
How is biotechnology used to bake bread?
Yeast is added to flour, salt and water and mixed. The yeast enzymes begin hydrolysing the starch in flour to maltose. Maltose produces monosaccharides used for aerobic respiration. When oxygen runs out, yeast respires anaerobically. Both anaerobic and aerobic respiration produce Co2 in bubbles through the dough and cause it to rise. Baking kills the yeast.
How is biotechnology used in the process of cheesemaking?
Two species of bacteria are added to milk and between them they ferment the lactose in the milk to lactic acid. Chymosin lowers the pH of the milk which causes the proteins in the milk to denature. Chymosin and pepsin (enzymes) are added to cause the milk proteins to coagulate forming curds (solid lumps) and whey (liquid).
Explain how biotechnology is used in the process of yoghurt production.
Two species of bacteria are added to milk. They ferment the lactose in milk to lactic acid. This causes the milk proteins to clump together and results in the sour taste of yoghurt.
Explain how biotechnology is used in the process of penicillin production.
In times of stress, fungi from the penicillium genus produces an antibiotic, penicillin, to stop bacteria growing and competing for resources. Penicillin is grown under stress in industrial fermenters and collated and processed to be used in medicine.
Explain how biotechnology is involved in the process of producing insulin.
Insulin is made by genetically modified bacteria which have had the gene for human insulin production inserted into their DNA. These bacteria are grown in batch fermenters and each bacterial cell expresses insulin. The insulin is released into the batch medium and can be purified.
