5.4 Cloning Flashcards
Cloning
The production of an organism, genetically identical to another.
Diploid nucleus
a nucleus that contains two sets of each chromosome
it is inserted into an enucleated egg cell during cloning
Explants
small samples from a parent plant that are used for micro propagation
Micro propagation
the multiplication of plants using tissue culture methods and can be used to produce large numbers of plants that are all genetically identical to one another
all with the desirable characteristics that the parent plant had
Tissue culture
a method of growing living cells/tissue in a medium to produce cloned plants
benefits of micropropagation
lots produced
genetically identical
faster/quicker
anytime of the year
What is meant by the term in vitro?
in test tube/petri dish
Describe the process of micropropagation
take small samples
sterilise
place into agar
provide minerals
plant growth substances
In micropropagation, small pieces of plant tissue can grow into new individual.
Explain why small pieces of animal tissue cannot grow into new individuals.
cells are differentiated
fewer stem cells
stem cells are found in embryo
describe the stages in the production of cloned mammals, sheep example
diploid nucleus taken from animals body cell (that has the desired characteristic)
unfertilized egg taken from animal B and nucleus containing, DNA is removed (enucleated)
diploid nucleus from animal A is inserted into the empty egg cell
egg cell triggered by sparks of energy to mitotically divide (mitosis)
once cells have turned into an embryo it is inserted into the uterus of animal C which acts as a surrogate mother (usually older animal)
clone of sheep A has developed
Steps to cloning in plants
healthy parent plant
small piece of tissue cut from plant (explant)
–> growing tip already in mitosis –> doesn’t need stimulant
tissue is then sterilised to remove bacteria
tissue is then chopped into smaller pieces to increase number of clones
each piece put into a test tube containing sterile agar jelly
agar is then changed to trigger shoots
plant then planted in sterile soil to continue growing
Why is the tissue sterilised?
prevents infection and competition
How is the agar jelly put in the test tube?
agar at a slope to prevent condensation
What does agar contain?
agar contains glucose, nitrates, water and plant auxins
What is meant by the term enucleated?
nucleus has been removed
What is the animal that gives birth to the cloned animal known as?
a surrogate
In adult cell cloning, where does the foetus develop?
uterus
In adult cell cloning, what type of cell do you take from the organism you want to clone?
Adult body cell
e.g. skin cell
What type of nucleus is used in adult cell cloning?
diploid nucleus
How was ‘Dolly the sheep’ produced?
Adult cell cloning
What is a transgenic organism?
an organism with DNA from another species
Suggest advantages of producing cows with desirable characteristics via embryo cloning, rather than via selective breeding.
all offspring are identical/no variation
it is faster
more offspring are produced
there is no need for natural mating/no need to keep two parents
Name the type of cell division that produces an embryo from an individual cell
mitosis
