F215 module 2 Biotechnology and gene technologies

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F215-Module 2-Biotechnology and Gene Technologies
5.2.1-Cloning in Plants and Animals
a. Outline the differences between reproductive and non-reproductive cloning
Reproductive cloning Non-reproductive cloning
Making cloned animals using eggs Using cloned cells to generate
and sperm. cells, tissues and organs to replace
Splitting embryos to make those damaged.
artificial identical twins. Use totipotent cells (capable of
Nuclear transfer by taking a differentiating into any adult cell).
differentiated cell from an adult To repair damage, not to make new
and placing it into an egg with its organisms.
nucleus. Sometime known as therapeutic
b. Describe the production of natural clones in plants using the example of
vegetative propagation in elm trees
Asexual reproduction after damage to the parent plant.
1. A healthy elm tree has a root sucker which grows a new tree.
2. The elm tree starts to show signs of Dutch elm disease.
3. The main stem is dead but the roots are still alive so root suckers are still
4. Root suckers grow producing new trees.
The root suckers are sometimes known as basal sprouts and they grow from the
meristem tissue in the trunk close to the ground.
c. Describe the production of artificial clones of plants from tissue culture
Taking cuttings
o A section of stem is cut between leaf joints (nodes).
o The cut end of the stem is treated with plant hormones.
o The cutting forms a new plant which is a clone of the original parent
o A shoot section of a woody plant is joined to an already growing root and
stem (stock).
o The graft grows and is genetically identical to the parent plant but the
root and stem is not.
Micropropgation by callus tissue culture
o An explant is taken which is a small piece of tissue from the plant usually
from the shoot tip.
o The explant is placed on a nutrient growth medium.
o A callus which is a mass of undifferentiated cells is formed by cells in
the tissue dividing.

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After a few weeks, single callus cells are removed from the mass and
placed on a growing medium containing plant hormones to encourage
shoot growth.
o After another few weeks, the shoots are transferred onto a different
growing medium containing different hormone concentrations that
encourage root growth.
o The growing plants (plantlets) are then transferred to a greenhouse to
get acclimatised and to grow bigger.
o They can then be transferred outside.
d.…read more

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An egg (ovum) that is haploid is taken from another adult and the nucleus
is removed making an enucleated cell.
o Using electro-fusion the nucleus is removed from the differentiated cell
and placed into the enucleated ovum.
o The cell is then placed into the uterus of another sheep.
o The early embryo is removed.
o This embryo is implanted into the surrogate mothers uterus.
o The sheep is born and is identical to the sheep which the nucleus has
come from.
f.…read more

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Bacteria prevent the growth of other bacteria that would cause
o Mycoprotein
Quorn/meat alternatives.
Fusarium is grown in culture.
Fungal mycelium is produced and separated which is to be
processed as a food.
o Naturally brewed soya sauce
Roasted soya beans are fermented with yeast or fungi like
Production of drugs/pharmaceutical chemicals
o Penicillin
Penicillum is grown in culture to produce the antibiotic as a
by-product of the metabolism.
o Insulin
E.coli is genetically modified to carry the human insulin gene.…read more

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E.g. Fusarium is grown on corn steep liquor which is a waste
product of the corn milling industry.
Why use microorganisms?
o They grow rapidly in favourable conditions, with them being able to
double in as little as 30 minutes (generation time).
o Can produce proteins and chemicals which are released into the
surrounding medium where they can be harvested.
o Can be genetically engineered to produce specific products e.g. Insulin.
o Can grow well in relatively low temperatures.…read more

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Lag phase
o The organisms may be taking in water, undergoing cell expansion,
activating specific genes and synthesising specific enzymes.
Log phase
o Sometimes known as the exponential phase.
o Population size increases each generation.
o There is enough space and nutrients to reproduce.
o Low amount of limiting factors.
o Birth rate > death rate.
Stationary phase
o Nutrient levels decrease.
o Waste products build up.
o Birth rate = death rate.
Decline/death phase
o Nutrient exhaustion.
o Increased level of toxic products.…read more

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The enzyme binds to it because of the hydrophobic interactions and ionic
o Adsorbing agents: porous carbon, glass beads, clays and resins.
o Enzymes can become detached because the bonding forces are not
strong (leakages).
o But if the enzyme molecules are held so their active site is not changed
and is displayed, adsorption can have very high reaction rates.
Covalent bonding
o Enzymes are covalently bonded to a support by covalently linking
enzymes together to an insoluble material like clay.…read more

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Immobilised enzymes are more stable because the immobilising matrix protects
the enzyme molecules.
f. Compare and contrast the processes of continuous and batch cultures
Continuous culture Batch culture
Higher growth rate because the Growth rate is slower because the
process is continuing and nutrients nutrient level decreases with time
are continuously added. as a fixed amount is added at the
Set up is difficult and maintenance
is harder. Easy to set up and maintain.…read more

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Oxygen concentration
o A lack of oxygen could lead to unwanted products of anaerobic
respiration and can reduce the growth rate.
o A change in pH can lead to the reduction of enzyme activity and
therefore reduce growth rates.
i. Explain the importance of asepsis in the manipulation of microorganisms
Asepsis-the absence of unwanted microorganisms.
Unwanted microoranisms can:
o Compete with microorganisms for nutrients and space.
o Reduce the yield of useful products.
o Cause spoilage of the product.…read more

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Comparing genes of different species can show evolutionary relationships. This
is because the more DNA sequences that they share, the closer related they
Comparing genes for the same or similar proteins across a range of organisms is
known as comparative gene mapping.
You can model the effect of changes to genes, for example yeast.…read more


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