6.4 Cloning and Biotechnology Flashcards
Define clones
Genetically identical organisms or cells
Define vegetative propagation
Reproduction from vegetative parts of a plant - usually an over- wintering organ.
Advantages of natural cloning
- if conditions are good for parent, they will be good for offspring
- rapid, take advantage of good conditions
- reproduction only with one parent
Disadvantages of natural cloning
- offspring may be overcrowded
- no genetic diversity
- little variation
- selection is not possible
- who population endangered with changes in environment
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 suckers?
New shoots that grow from the roots of a plant
the original branch may die and leave it as a separate individual stem
What are stolons ?
Also known as runners, horizontal stem structures that grow away from the plant above ground.
What are tubers?
large underground plant structures that act as a food store for the plant.
What are bulbs?
Underground food stores. New bulbs can develop from the original bulb and form new plants
Example of rhizomes
Bamboo
Example of Stolon
Strawberries
Example of sucker
Elm trees
Example of tubers
potato
Example of bulb
onions
How to form cutting
1) use scalpel to take cutting from parent plant
2) remove leaves from lower end, leaving one
3) dip lower end in rooting powder (with hormones)
4) put in growth medium
5) warm moist environment ( plastic bag or propagator)
6) plant elsewhere when strong enough
Explain tissue culture
1) cells taken OG plant (from stem and root tips bc stem cells)
2) sterilised to kill bacteria/ fungi that compete + decrease growth rate
3) put on growth medium with nutrients and growth hormones
4) when becomes smol plant, taken out of growth medium and planted in soil
When is tissue culture used?
When plants are rare
To grow whole plants from genetically engineered plant cells
Describe micropropagation
Cells are taken from developed cloned plants and subcultured (grown on another fresh culture medium) creating a large number of clones
Arguments for artificial cloning
- Desirable genetic characteristics always passed onto clones
- Tissue culture allows reproduction in an season if environment is controlled
- Less space required by tissue culture than growing
- Lots of plants quickly compared to growing from seeds
- Can grow plants that have lost their ability to reproduce sexually (e.g. bananas and rare plants)
Arguments against artificial cloning
- undesirable genetic characteristics are always passed on
- no genetic variability (disease could kill all)
- production costs are high bc high energy use + skilled workers so unsuitable for small scale
- contamination by microorganisms can cause complete loss
Define embryo twinning
splitting an embryo to create two genetically identical embryos
Define enucleation
Removal of the cell nucleus
Define somatic cell nuclear transfer (SCNT)
a technique that involves transferring the nucleus from a somatic cell to an egg cell
What two methods of artificial cloning are there in animals?
Artificial embryo twinning
Somatic cell nuclear transfer (SCNT)
Describe artificial embryo twinning
1) egg cell extracted ad fertilised in petri dish
2) left to divide at least once, forming an embryo
3) individual cells from embryo are separated and each put in a petri dish
4) each cell divides and develops normally so an embryo forms in each petri dish
5) implanted into surrogate mothers where they are born
Describe SCNT
1) somatic cell taken from A, the nucleus is extracted and kept
2) An oocyte (immature egg cell) is taken from B, its nucleus is removed
3) nucleus from A is put in enucleated cel from B
4) they are fused together and stimulated to divide (electrofusion) and this makes an embryo
5) implanted into surrogate mother and a clone of A is formed
Describe some uses of animal cloning
- research drugs (variables that come from genetic differences are removed)
- save endangered animals from extinction
- agriculture so farmers can increase no. with desirable characteristics
- animals that have been genetically modified could be cloned
- cloning embryonic stem cells to replace damaged tissue
Arguments for artificial animal cloning
- desirable characteristics passed on
- infertile animals can be reproduced
- increasing endangered species = biodiversity
- dont have to wait until breeding season
- new treatments for disease
Arguments against artificial animal cloning
- difficult, time-consuming and expensive
- undesirable characteristics passed on
- its suggested that clones may not live as long as natural offspring
- cloned human embryos = destroying life
Define biotechnology
the use of living organisms or parts of living organisms in industrial processes. This could be to produce food, drugs or other products
Four main areas of biotechnology
food, pharmaceutical drugs, enzymes and other products
Examples of drugs made by biotechnology
penicillin and insulin
Why are microorganisms used in biotechnology?
- ideal conditions are easily created
- short life cycle, grow rapidly
- can be grown on inexpensive materials
- any time of year
Role of microorganisms in brewing
yeast added to grain and respires anaerobically to produce ethanol and CO2 - fermentation
Role of microorganisms in baking
yeast makes bread rise