Transcript Structure, function and growth of prokaryote and eukaryote cells

Structure, function and growth of
prokaryote and eukaryote cells
(iii) Differentiation of cells
into tissues and organs.
(iv) Cell and tissue culture
–Mammalian
cell cultures
–Bacterial and Fungal
Cultures
(v) Plant tissue culture
Plant Tissue Culture
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Plant tissue culture is used to create clones.
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This is useful
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To create pathogen free species
Create crop species that have identical traits (e.g.
height)
Save endangered species
Somatic Fusion (Protoplast hybridisation) is
used to create new varieties.
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Plant tissue culture is then used to grow the plant
Somatic Fusion
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Cells from two different plants are selected
Cell wall is removed using cellulase and
pectinase
Protoplasts are fused using either
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Polyethylene Glycol
Electrical shock
Protoplast is grown using tissue culture
Plant Tissue Culture
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Source of cell / tissue
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Small pieces of tissue are taken from a plant.
These are called explants.
Protoplast from somatic fusion.
Plant cells / tissue have a long life span
Suitable container
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Anything sterile (the entire procedure must be
carried out under aseptic conditions).
Plant tissue culture cont…
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Growth Medium
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Simple (can be liquid or solid) containing carbon
source, minerals salts, water, vitamins
Contains plant growth regulators to cause tissue
differentiation e.g.
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Cytokinins promote shoot development
Auxins promote root development
Plant tissue culture cont…
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Events in Plant Tissue culture
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Explant is removed and sterilised.
It is transferred to growth media
A mass of undifferentiated cells called the callus forms (this
occurs due to auxin and cytokinin concentrations being
balanced).
Tissue is transferred to growth media containing different
concentrations of growth regulators to promote shoot and
root production.
Tissue culture plants acclimatised in greenhouses.
Totipotency
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Totipotency is the cell’s ability to differentiate.
In theory, all cells have this potential as they
have the same genome (nuclear
totipotency)
In practise,
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Plant cells are totipotent
Mammalian cells vary
e.g. Stem cells are totipotent
Learning Activities
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Dart pg 23 – 24
Scholar (Unit 1, 3.4 – 3.6)
Plant Tissue Culture
Advanced Higher Biology Questions
Create a table to compare the 3 types of
tissue culture
Create flow diagrams of the tissue cultures
Create a glossary