Cloning and Biotechnology Flashcards
Define clone
Offspring which is genetically identical to the parent organism
Define asexual reproduction
The generation of new individuals by mitosis to produce clones
Define vegetative propagation
The production of plant clones from non-reproductive tissues
Give 4 ways plants naturally clone
- Bulbs
- Runners
- Rhizomes
- Stem tubes
What is ‘taking a cutting’?
Removing and planting short sections of stem of a plant in order to produce clones of that plant
How can the success of cuttings be improved?
- Use hormone rooting powder
- Reduce the number of leaves
- Cover with a plastic bag for a few days
- Make an oblique cut in the stem
Give 2 advantages of taking cuttings over seeds
- less time is needed to grow an adult plant
- gurantees quality of plants as their characteristics are known
Give a disadvantage of taking cuttings over using seeds
-lack of genetic variation in offspring
What is micropropagation?
The process of producing large numbers of genetically identical offspring from a single plant using tissue culture
Why might micropropagation be used to clone a plant?
If a plant:
- does not readily produce seeds
- does not respond well to natural cloning
- is very rare
- has been genetically modified with difficulty
Where must tissue be taken from in the tissue culture of plants?
From the shoot tips or buds
What type of tissue must be used to micropropagate a plant?
Meristematic
Define explant
The material removed from the plant which is being cloned
Outline the steps in micropropagation of a plant
- Take some tissue from the shoots or roots of a plant
- Sterilised the sample (using bleach or ethanol)
- Place the explant in sterile culture medium containing plant hormones which stimulate mitosis
- Mass of cells (callus) is divided and put into new culture medium which stimulates plantlet growth
- Plantlets are potted into compost
Why must micropropagation be done under sterile conditions?
In order to prevent the plant tissue from becoming contaminated with bacteria or fungi
Give 4 advantages of micropropagation
- allows for rapid production of large numbers of plants
- provides a reliable way to increase numbers of rare/endangered plants
- plants can be produced at any time of year
- GM plants can be produced in large numbers
Give 4 disadvantages of micropropagation
- produces a monoculture
- expensive and requires skilled workers
- if source material is infected with a disease, all clones will be
- explants and plantlets are vulnerable to infection
What is a callus?
A mass of undifferentiated cells
Give 3 examples of plants grown by micropropogation
- potatoes
- sugar cane
- bananas
Give an example of a plant grown by taking cuttings
Sugar Cane
Give an example of natural cloning in vertebrates
Monozygotic twins
Give 2 ways in which animals can be artificially clones
- Artificial twinning
- Somatic cell nuclear transfer
Outline the steps in artificial twinning
- Animal with desirable trait is treated with hormones so she produces more mature ova than usual
- Mature eggs are removed and fertilised by semen in the lab
- When totipotent, the embryonic cells are split to produce several small embryos
- Embryos are then implanted into the womb of surrogate mothers
Why is artificial twinning carried out?
- Greatly increases the number of offspring produced by animals with best genes
- embryos can be frozen and the success of the animals can be assessed before all embryos are brought to term
Outline the process of somatic cell nuclear transfer
- A nucleus is removed from a somatic cell of an animal
- A nucleus is removed from an egg cell of a different animal, the somatic cell nucleus is then placed in the enucleated egg cell
- A mild electric shock fuses the cell and nucleus and they begin dividing
- Embryo is transferred into a surrogate
Give 4 advantages of somatic cell nuclear transfer
- enables GM embryos to be replicated
- useful for pharming
- enables scientists to clone specific animals
- enables rare, endangered, or extinct animals to be reproduced
Give a disadvantage of somatic cell nuclear transfer
It is a very inefficient process, many eggs are used to produce a single clone
Give 3 advantages of animal cloning
- Desirable genetic characteristics are always passed on
- Infertile animals can be reproduced
- Can be used to increase the population of an endangered species, helping to preserve biodiversity
Give 2 disadvantages of animal cloning
- many cloned animal embryos fail to develop
- animals produced by cloning have shortened lifespans
What is pharming?
When animals are geneticially modified to produce pharmaceuticals e.g. human proteins produced in milk
What is theraputic cloning?
A form of somatic cell nuclear transfer which has the potential to grow replacement organs which will not trigger an immune response
What is biotechnology?
The exploitation of biological processes for use in industrial processes
Give 4 reasons why microorganisms are useful for biotechnology
- No welfare issues to consider
- Can be easily genetically modified
- Rapid growth rate
- Conditions for growing and nutrient requirements are relatively cheap
What is indirect food production?
When products made by microorganisms are used to make food (i.e. the microorganisms themselves are not eaten)