Cloning Flashcards
What is a clone?
A genetically identical copy, derived from the same genetic material as an original organism, cell or gene.
Produced naturally or artificially.
What are the two main processes of natural cloning in plants?
Asexual reproduction. (eukaryotic)
Vegetative propagation.
How is asexual reproduction an example of natural cloning in plants?
Mitosis provides the mechanism by which cells are cloned.
Mitosis is responsible for asexual reproduction.
What is vegetative propagation?
The production of structures in a plant that can grow into new individuals, which are clones of the parent.
What are some examples of vegetative propagation?
Strawberry plants form runners.
Tubers and bulbs can grow new buds producing genetically identical plants.
Leaflets drop to the ground, producing new genetically identical plants.
What is the name of the process of artificial cloning in plants?
Micropropagation by tissue culture.
What is micropropagation?
The process of making large numbers of clones from a single parent plant using tissue culture techniques.
In what situations is artificial cloning of plants useful? (5)
Propagating an infertile plant.
Propagating rare or endangered plants.
Propagating plants that are difficult to selectively breed.
Propagating plants that have been genetically modified.
If the plantlets need to be transported.
What are the 4 stages in the micropropagation of a plant?
Explant
Callus
Plantlet
Young Plant
What must be done to an explant to form a callus?
The explants are sterilised and grown on agar jelly containing nutrients and plant growth hormones, forming a totipotent callus.
What is done to a callus to form plantlets?
The callus is subdivided and differentiated using plant growth regulators forming plantlets.
What is done to a plantlet to form a young plant?
Plantlets are grown in sterile soil in a greenhouse.
What are the advantages to the cloning of plants? (4)
Clones inherit good genes from the parent plant.
Allows an area to be populated very quickly.
Can occur if sexual reproduction not possible.
Plants can be produced external of environmental influences (seasons). (artificial)
What are the disadvantages to the cloning of plants?
There is no genetic variation between clones, so cloning reduces the genetic diversity of the population.
- prevents the species from adapting via natural selection to a changing environment.
- leaves the population vulnerable to disease.
What is the process of natural cloning of animals?
Identical twins (monozygotic twins). This happens when the blastocyst naturally cleaves in two (embryo splitting).
What are the two processes of artificial cloning of animals?
Somatic Cell Nuclear Transfer (SCNT)
Embryo splitting
Describe the process of SCNT.
Egg cell (gamete) taken from donor and enucleated using a micropipette.
Nucleus taken from a somatic cell of the individual to be cloned and inserted into the enucleated egg cell.
The process of electrofusion allows this.
The young embryo completes its development in a surrogate mother.
Why are electric shocks required in SCNT?
To insert the somatic nucleus into the enucleated egg cell and to cause the cell to begin development as if it had been fertilised.
Describe the process of embryo splitting.
Sperm and eggs (gametes) taken from donor organisms with desirable genes.
In vitro fertilisation.
The embryo is split into several fragments.
The fragments are implanted into multiple surrogate mothers.
What is the main difference between the result of embryo splitting as opposed to SCNT?
In embryo splitting, the offspring are not clones of a known organism, but clones of one another.
What are the uses of embryo splitting?
Useful for research as different treatments can be compared without having to allow for differences in genotype.
Production of desirable animals for agriculture.
Allows embryos to be frozen and transported after the success of the offspring is asserted.
What are the uses of SCNT?
Pharming.
- production of therapeutic human proteins.
- GMO’s to grow organisms for human transplant.
- production of animal models for research.
What are some positives (ethical) of animal cloning?
Cloning can be useful in preventing the extinction of highly endangered species.
Cloning is very important in clinical trials for new therapies and pharmaceuticals, especially when using transgenic animals.
Cloning can be used to increase the yield of farmstock, accelerating the traditional process of selective breeding. -high value herds can be created quickly
What are some negatives (ethical) of animal cloning?
SCNT is highly inefficient and the vast majority of cloned embryos fail to develop properly.
Most cloning procedures cause the suffering of animals.
There is evidence that clones have a higher mortality rate, even once fully developed.
