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Igcse biology edexcel 5.10 5.20

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Edexcell ppt Biology 5.10 - 5.20 Used in lessons to scaffold class teaching and as a revision resource for students
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Selective Breeding 5.10 understand that plants with desired characteristics can be developed by selective breeding 5.11 understand that animals with desired characteristics can be developed by selective breeding.
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Page 1: Igcse biology edexcel 5.10 5.20

Selective Breeding 5.10 understand that plants with desired characteristics can be developed by selective breeding

5.11 understand that animals with desired characteristics can be developed by selective breeding.

Page 2: Igcse biology edexcel 5.10 5.20

Definition5.10 understand that plants with desired characteristics can be developed by selective breeding

5.11 understand that animals with desired characteristics can be developed by selective breeding.

Selective Breeding:a. Individuals with desired characteristics are

bred togetherb. This is to produce offspring which express

desired characteristics.c. Offspring with desired characteristics are

bredd. Repeat over many generations

Page 3: Igcse biology edexcel 5.10 5.20

Examples:

Increased yield and reduction of stem length in wheat

Increased yield of meat and milk in cattle.

Examples5.10 understand that plants with desired characteristics can be developed by selective breeding

5.11 understand that animals with desired characteristics can be developed by selective breeding.

Page 4: Igcse biology edexcel 5.10 5.20

Selective Breeding Points5.10 understand that plants with desired characteristics can be developed by selective breeding

5.11 understand that animals with desired characteristics can be developed by selective breeding.

• Process of controlled sexual reproduction• Potentially can take thousands of years• Can lead to huge variation in a species. Example: dog family

Page 5: Igcse biology edexcel 5.10 5.20

Selective Breeding(a simple how to guide…. again)

5.10 understand that plants with desired characteristics can be developed by selective breeding5.11 understand that animals with desired characteristics can be developed by selective breeding.

• Identify individual organisms that have a desirable trait in a population.

• Breed these individuals together.• From offspring choose those with the

desirable trait.• Breed these offspring together.• Continue for a long, long, long time

Page 6: Igcse biology edexcel 5.10 5.20

Genetic ModificationSyllabus points 5.12 – 5.20

Page 7: Igcse biology edexcel 5.10 5.20

Review the structure of DNA:

DNA is a double-stranded molecule. The strands coil up to form a double-helix. The strands are linked by a series of paired bases.

Thymine (T) pairs with Adenine (A) Guanine (G) pairs with Cytosine (C)

Genetic ModificationSyllabus points 5.12 – 5.20

Page 8: Igcse biology edexcel 5.10 5.20

Process of Genetic Engineering5.14 understand that large amounts of human insulin can be manufactured from genetically modified bacteria that are grown in a fermenter

The example you need to know is the creation of E coli bacteria that makes human insulin.

However, a more fun example is Alba, the glow-in-the-dark bunny, and pigs that makes the protein luminol (FGP)

(taken from a jellyfish!)

Page 9: Igcse biology edexcel 5.10 5.20

TRANSGENIC ORGANISMS5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together

The organism that receives the new gene from a different species is a transgenic organism.

Page 10: Igcse biology edexcel 5.10 5.20

PROCESS 5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together

1) Plasmids are isolated from a bacterium.

2) They are cut open with a specific restriction enzyme.

3) The gene to be transferred is cut from the donor DNA using the same restriction enzyme, so that the plasmid and the gene have the same sticky ends and can be joined together. (ends match)

Page 11: Igcse biology edexcel 5.10 5.20

4) The 'opened-up' plasmids and the isolated gene are mixed with a DNA ligase enzyme to create recombinant plasmids.

5) Bacteria are incubated with the recombinant DNA.

6) Some bacteria will take up the plasmids.

PROCESS 5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together

Page 12: Igcse biology edexcel 5.10 5.20

7) The bacteria that have taken up the plasmid now contain the gene from the donor cell. This could be a gene controlling the production of human insulin.

8) So the bacterium is transgenic.

PROCESS 5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together

Page 13: Igcse biology edexcel 5.10 5.20

Making a Transgenic Bacterium5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together

On your diagram include the enzymes used to ‘cut’ and ‘stitch’ back to together the DNA. Include where the Vector would be used.

Page 14: Igcse biology edexcel 5.10 5.20

• Common vectors include Viruses and Plasmids

• Now your transgenic bacterium is complete. All you need to do is grow it in a fermenter and it makes lots of insulin for you!

5.13 describe how plasmids and viruses can act as vectors, which take up pieces of DNA, then insert this recombinant DNA into other cells

Page 15: Igcse biology edexcel 5.10 5.20

Putting it all together5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together

Page 16: Igcse biology edexcel 5.10 5.20

Transgenic Organism 5.16 understand that the term transgenic means the transfer of genetic material from one species to a different species. (TA)

Organism containing DNA from two or more sources (i.e. an organism that’s been genetically engineered to

express a foreign gene)

Plants are good to genetically engineer because they are more simple and there are fewer ethical issues.

Page 17: Igcse biology edexcel 5.10 5.20

Genetically modified (GM) crops are engineered to: 5.15 evaluate the potential for using genetically modified plants to improve food production (illustrated by plants with improved resistance to pests)

• Have bigger yields • Produce their own insecticide• Be frost resistant (e.g. frost resistant strawberries) • Have resistance to disease • Grow in harsher environments (e.g. drought-resistant rice)• Grow in harsher environments (e.g. salt resistant wheat) • Have a longer sell-by date (e.g. non-squash tomatoes) • Be a different colour / taste to normal (e.g. chocolate flavoured

carrots) • Have vitamins in them that they would not normally have (e.g.

golden rice) • Have stronger taste (e.g. chilli's) • Be easier to eat (e.g. easy-peel oranges)

Page 18: Igcse biology edexcel 5.10 5.20

CLONINGSyllabus points 5.17 – 5.20

Cloning is used to make many copies of a single individual. Usually the individual has a very desirable phenotype and has often been produced at the end

of a Selective Breeding or GE programme.CLONES ARE: Genetically Identical Organisms

Start 2min

Page 19: Igcse biology edexcel 5.10 5.20

Cloning in Plants5.18 understand how micropropagation can be used to produce commercial quantities of identical plants (clones) with desirable characteristics

The easiest way to clone a plant is to take a cutting or a graft (asexual reproduction).

However, micro propagation (tissue culture) can be used in large-scale cloning programmes.

Which desirable characteristics in cloned plants do you want to express (selective breeding vs GM)?

Page 20: Igcse biology edexcel 5.10 5.20

Diagram of Propagation 5.17 describe the process of micropropagation (tissue culture) in which small pieces of plants (explants) are grown in vitro using nutrient media

Page 21: Igcse biology edexcel 5.10 5.20

Diagram of Propagation 5.17 describe the process of micropropagation (tissue culture) in which small pieces of plants (explants) are grown in vitro using nutrient media

Page 22: Igcse biology edexcel 5.10 5.20

Micro propagation 5.17 describe the process of micropropagation (tissue culture) in which small pieces of plants (explants) are grown in vitro using nutrient media

1) Micro-propagation - small pieces of plants (explants) or tissue samples are grown in a Petri dish on nutrient medium (agar). Growing a living organism in an artificial environment is

called In Vitro.

2) Hormones / bleach are added to the explant so it will grow into a miniature plant (a plantlet).

3) This can be done on a huge scale to produce 1000s of plantlets from a single culture.

Page 23: Igcse biology edexcel 5.10 5.20

How do you draw it?Include vocabulary:Auxin/BleachNutrient agarIn VitroCutting/Tissue Sample/explantsPlantlets(you can include more)

Diagram of Propagation 5.17 describe the process of micropropagation (tissue culture) in which small pieces of plants (explants) are grown in vitro using nutrient media

Page 24: Igcse biology edexcel 5.10 5.20

Advantages and Disadvantages to clones 5.17 describe the process of micropropagation (tissue culture) in which small pieces of plants (explants) are grown in vitro using nutrient media

Page 25: Igcse biology edexcel 5.10 5.20

Animal Cloning 5.19 describe the stages in the production of cloned mammals involving the introduction of a diploid nucleus from a mature cell into an

enucleated egg cell, illustrated by Dolly the sheep

• Take an embryonic cell

• Remove it’s nucleus (enucleate it) • Replace with the nucleus from an adult cell (from the

animal you want to clone)

• Give it an electrical shock

• The embryonic cell grows into an embryo clone of the adult, from which the donor nucleus came

Page 26: Igcse biology edexcel 5.10 5.20

This process was used to create Dolly the sheep

Animal Cloning 5.19 describe the stages in the production of cloned mammals involving the introduction of a diploid nucleus from a mature cell into an

enucleated egg cell, illustrated by Dolly the sheep

Page 27: Igcse biology edexcel 5.10 5.20

Animal Cloning 5.19 describe the stages in the production of cloned mammals involving the introduction of a diploid nucleus from a mature cell into an

enucleated egg cell, illustrated by Dolly the sheep

Page 28: Igcse biology edexcel 5.10 5.20

WHY CLONE? 5.20 evaluate the potential for using cloned transgenic animals, for example to produce commercial quantities of human antibodies

or organs for transplantation. (TA)

Cloning can be used beneficially in agriculture to increase the yield of crop plants.

Cloning genetically engineered animals organisms allows us to mass-produce very useful organisms e.g. the E. coli bacterium that makes human insulin has been cloned many times.

Now all diabetics have access to human insulin.

Page 29: Igcse biology edexcel 5.10 5.20

Making Insulin5.20 evaluate the potential for using cloned transgenic animals, for example to produce commercial quantities of human antibodies or organs

for transplantation. (TA)

Page 30: Igcse biology edexcel 5.10 5.20

Human antibodies5.20 evaluate the potential for using cloned transgenic animals, for example to produce commercial quantities of human antibodies

or organs for transplantation. (TA)

To make human antibodies:1.Create transgenic mice

with human DNA (for immune system)

2.Infect mice with disease3.Mice produce human

antibodies to disease4.Collect mouse blood and

remove antibodies5.Inject sick humans with

antibodies

1)Milk it or Bleed it2)Can give more blood

Page 31: Igcse biology edexcel 5.10 5.20

COMMERCIAL ORGANS FROM CLONES!!!!

5.20 evaluate the potential for using cloned transgenic animals, for example to produce commercial quantities of human antibodies or organs for transplantation. (TA)

The key word to this syllabus point is EVALUATE

1) Morality2) Political3) Religious

Start 11.15

Page 32: Igcse biology edexcel 5.10 5.20

The CLONE Wars!!!!5.20 evaluate the potential for using cloned transgenic animals, for example to produce commercial quantities of human antibodies or organs

for transplantation. (TA)

Advantages

Disadvantages

Development of cloned animals which have been genetically engineered to produce valuable proteins in their milk or blood.

Create identical organisms with exact genetic characteristics required.

Cloning can save animals form extinction.

Concerns about the ethics of cloning.

Cloning limits variation. This can effect natural selection.

Concerns about using the technique to clone humans in the future.

Page 33: Igcse biology edexcel 5.10 5.20

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