6.2.1 Cloning and Biotechnology Flashcards
What are clones?
Genetically identical copies of organisms or cells.
How are clones produced?
Asexual Reproduction - where the nucleus divides by mitosis. No genetic variation although there may be some chemical and psychological changes.
What happens during mitosis?
Creates two identical copies of the DNA
Can clones occour naturally?
Yes - with organisms that reproduce asexually
What are the advantages of natural cloning?
if the conditions are good for the parent then they will be good for the offspring.
Rapid so the population can increase quickly (allows them to take advantage of suitable environmental conditions that may not be around for long).
Reproduction can still take place with only one parent.
What are the disadvantages of natural cloning?
Offspring may become overcrowded.
No genetic diversity (except those caused during mutations).
The population shows little genetic diversity.
Selection is not possible.
The whole population is susceptible to environmental changes.
What is vegetative propagation?
The process of reproduction through vegetative parts of the plant rather than specialised reproductive structures.
What are Runners/Stolens?
stems that grow horizontally from the plant at certain points and grow on the surface of the soil.
What are Rhizomes?
stems that grow horizontally from the plant at certain points and grow under the soil.
What are suckers?
Stems that grow from the root of the plant to form new plants.
What happens once Runners/Stolens, Rhizomes and Suckers have formed?
The horizontal branch dies and leaves the new stem as a separate individual.
What are Bulbs?
An underground stem that grows a series of fleshy leafy bases.
What is the main characteristic of a bulb?
There is an apical bud that grows into the plant in the spring. They typically have more than one apical bud that grows into new plants.
What are corms?
An underground stem with scaly leaves and buds. In the spring they grow into plants.
How do corms differ to bulbs?
Corms are similar to bulbs but are solid rather than fleshy.
How are leaves involved in vegetative propagation?
New leaves can be produced from leaf margins
What are tubers?
Underground stems that grow into a plant. Each tuber produces more later in the year
What is an example of a tuber?
Potatoes
What are examples of natural cloning in animals?
Identical twins.
Asexual reproduction.
How are identical twins produced?
The fertilised egg (zygote) divides as normal but the daughter cells then split to become two separate cells. Each cell grows and develops into a new individual.
What are examples of asexual reproduction in animals?
Water flea and greenfly are able to asexually reproduce to produce clones if needed.
What is the most efficient way to make plant clones?
Cuttings
How are cuttings used to produce clones?
The stem is cut between two nodes (leaf joints). The cut end is placed in moist soil and new roots will grow from the tissue in the stem.
How can root growth be stimulated on cuttings?
By dipping in auxin
Why are cuttings used to produce closes?
You can produce a large number of plants very quickly.
Where can cuttings be obtained from?
Stems, roots, scions and leaves
What are scions?
Dormant woody twigs
What is tissue culture?
Techniques used to grow cells, tissues or organs from a small sample of cells or tissue. Done in a nutrient medium under sterile conditions.
When is tissue culture used?
In commercial situations to increase the number of plants.
What is an example of tissue cloning?
Micropropagation
What is micropropagation?
Taking a small piece of plant tissue (known as the explant) and using plant growth substances to encourage it to grow and develop into new plants.
What is the process of micropropagation?
Plant material is selected and cut into small pieces (explants). Meristems are typically used.
Explants are sterilised using dilute bleach or alcohol.
Explants were placed on a sterile growth medium containing suitable nutrients.
This stimulates division by mitosis to form a callus.
The callus divides to form more clumps of totipotent cells.
The clumps are stimulated into plant tissue.
Plants are transferred to a greenhouse to grow more and acclimatise to normal growing conditions.
Why are meristems typically used as explants?
They are free from viral infection
What is used to sterilise explants?
Dilute bleach or alcohol
Why are the explants steralised?
To kill bacteria and fungi that will thrive in the micropropagation conditions
What is the growth medium for micropropagation?
Typically agar gel
What is contained within the growth medium for micropropagation?
Glucose, amino acids and phosphates as well as high concentrations of auxin and cytokines.
What is a callus?
A mass of totipotent cells
What are totipotent cells?
Undifferentiated cells
What are the pros of artificial cloning?
Rapid way of producing new plants (compared to growing from seed).
Can be done where sexual reproduction is not possible.
Plants will be genetically identical to the parent plant so will have the same desirable characteristics.
Unusual characteristics, from genetic modification or mutations, don’t risk being lost through sexual reproduction.
All plants are uniform in phenotype, making them easier to grow and harvest together.
Using the apical bud (meristems) as the explant ensures that it is virus free.
Why may sexual reproduction not be possible in plants?
Plants that have lost the ability to reproduce (like commercially grown bananas) can still reproduce.
Some plants are hard to grow from seed.
What are the disadvantages of artificially cloning plants?
Its labour intensive and expensive to set up the facilities to do tissue culture successfully.
Can fail due to microbial contamination.
All cloned offspring are genetically identical so are susceptible to the same pests/diseases.
No genetic variation (except that brought by mutations).
What is the disadvantage of all the cloned plants having the same susceptibility to pests/diseases?
They allow rapid spread of disease or pests between closely related plants
What is needed to artificially clone animals?
Totipotent cells - which can divide and differentiate into all types of cells in an adult.
Where is the only place you can get truly totipotent cells in an animal?
Early embryo cells
What is reproductive cloning?
Producing large numbers of genetically identical animals
When might reproductive cloning be useful?
Elite farm animals produced by selective breeding can be maintained.
Producing genetically modified animals with unusual characteristics.
What unusual characteristics have been produced in animals?
Goats that produce spider silk in their milk.
Cows that produce less methane.
What are the types of reproductive cloning?
Embryo Twinning.
Stomatic Cell Nuclear Transfer (SCNT).
What is embryo splitting?
A method of cloning that mimics the natural methods, but forces it to happen artificially.
What happens in embryo splitting?
Fertilisation happens by in vitro fertilisation (IVF) to produce a zygote.
The zygote divides by mitosis to form a small ball of 16 cells.
The embryo is then split into multiple embryos which are allowed to continue to divide.
The embryos are transplanted to a surrogate mother.
What type of clone does embryo twinning produce?
The offspring are all clones but are not clones of the parent(s).
What is the disadvantage of embryo twinning?
The quality of the offspring is not known untill they are born (you cant choose the genes, they are still random).
It depends on the sperms and the egg used and what genes they contained.
What is a surrogate?
A female that contains a child that is not its own - not genetically linked.
What does SCNT stand for?
Stomatic Cell Nuclear Transfer
What is the advantage of using SCNT?
The only way of producing a clone of an adult animal - the phenotype is known before cloning starts.
What was the first major example of successful SCNT cloning?
Dolly the sheep
What is the process of SCNT?
An egg is obtained from a donor and is enucleated.
A normal stomatic (body) cell is removed from the animal to be cloned.
The nucleus is removed from this cell and is inserted into the enucleated egg cell.
An electric shock is applied to trigger the egg to start developing.
The ovum then starts to develop and divide by mitosis.
The young embryo is then transferred to the uterus of a surrogate mother.
What does enucleation mean?
The removal of the nucleus from a cell
What type of clone does SCNT produce?
The offspring is a clone of the nucleus donor.
Why is an electric shock used in SCNT?
It makes the membrane unstable, allowing the nucleus to enter. Also starts the formation of spindle fibers to start mitosis.
What is non-reproductive cloning?
The production of cloned cells and tissues for purposes other than reproduction
What is therapeutic cloning?
Growing new tissues and organs for those who need it.
What are examples of where therapeutic cloning can be used?
Skin - grown in vitro as a graft over burned areas.
Repairing the spinal cord.
Produce beta cells for insulin production in the pancreas (diabetes treatment).
Growing whole organs to replace diseased ones.
What is the advantage of therapeutic cloning?
The tissues will be grown from the patients own cells so will be genetically identical so will avoid being rejected. A issue with transplanting donated organs.
How is cloning used for scientific research?
Allows research into the genes that control development and differentiation.
Used to test drugs and medication and their effect on different tissues and organs.
What are the advantages of artificially cloning animals?
Produce large heards with desirable characteristics.
Produce lots of high value animals.
Scientific research.
Testing Drugs.
No tissue rejection during trasplants.
Endangered species could be cloned.
What are the disadvantages of artificially cloning animals?
Unexpected side effects.
No genetic variation.
All venerable to the same diseases/pests.
Animals produced with little regard to welfare.
Low success rate.
Expensive.
Cloned animals are less healthy and have shorter life spans.
Ethical issues - creating a life to destroy.
Doesn’t increase the genetic variation when cloning endangered species.
Why are cloned animals less healthy and have shorter life spans?
Any genetic diseases that form later in life (e.g. arthritis) from the adult are passed onto the offspring from birth.
What is biotechnology?
The merging of biology and technology. The use of living organisms, or parts of living organisms, in industrial processes to produce food, drugs or other products.
What is used to produce ethanol in beer/wine?
Bacteria - saccharomyces cerevisiae - Yeast
What is used to make bread rise?
Bacteria - saccharomyces cerevisiae - Yeast
What is used to make cheese/yoghurt?
Bacteria - Lactobacillus bulgarus + Streptocollus thermophilus
What is used to produce mycoprotein?
Fungi - Fusarium venenatum
What is used to produce soya?
Bacteria - saccharomyces cerevisiae (yeast) + Aspergillus
What is used to make penicillin?
Bacteria - Penicillium
What is used to make antibiotics?
Bactria/fungi - Stropomyces genus
What is used to produce insulin?
Genetically modified bacteria
Where is protease/lipase used?
Washing powder
What is used to make protease and lipase?
Bacteria - bacillus licheniformes
What is pectinase used for?
Juicing
What is used to make pectinase?
Bacteria - Aspergillus Niger
Where is sucrose used?
Sweetener
What is used to make sucrose?
Bacteria - saccharomyces cerevisiae (Yeast) + aspergillus SPP
What is amylase used for?
Sweetener
What is used to make amylase?
Bacteria - A.Oryzare
