1. iGCSE Biology Section 5 lesson 2

2. Uses of biological resources
Content
Section 5
Uses of biological resources
Food production
Selective breeding
Genetic modification (genetic engineering)
Cloning

3. Lesson 2 b) Selective breeding c) Genetic modification Content
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.
c) Genetic modification
5.12 describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together
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
5.14 understand that large amounts of human insulin can be manufactured from genetically modified bacteria that are grown in a fermenter
5.15 evaluate the potential for using genetically modified plants to improve food production (illustrated by plants with improved resistance to pests)
5.16 understand that the term ‘transgenic’ means the transfer of genetic material from one species to a different species.

4. Selective breeding
Selective breeding is a method used for many years by farmers and growers to improve crops and yields. For example, milk production or disease resistance.

5. Selective breeding
Selective breeding aims to improve the features of a species.
Eg. To produce leaner pigs:
Select pigs with the least fat and mate them
Select the best of the offspring and mate these
Continue selecting and breeding over many generations.

6. Selective breeding
Disease-resistant wheat has also been developed by cross – breeding wheat plants with disease resistance and wheat plants with a high yield.

7. Selective breeding
Disease-resistant wheat has also been developed by cross – breeding wheat plants with disease resistance and wheat plants with a high yield.
The stalk of the wheat plant has also been developed by selective breeding to make it shorter and stronger – helps with harvesting.

8. Selective breeding
Milk yield in dairy cattle has been increased by selecting bulls from high yield herds and breeding them with cows that have the best milk production

9. Selective breeding
Milk yield in dairy cattle has been increased by selecting bulls from high yield herds and breeding them with cows that have the best milk production

10. Other examples of selective breeding
ROSES –bred for colour, shape and scent.

11. SHEEP – bred for quality wool and lamb production
Other examples of selective breeding
ROSES –bred for colour, shape and scent.

12. SHEEP – bred for quality wool and lamb production
Other examples of selective breeding
APPLES – bred for colour, taste and texture
ROSES –bred for colour, shape and scent.

13. SHEEP – bred for quality wool and lamb production
Other examples of selective breeding
DOGS – bred for speed and endurance
APPLES – bred for colour, taste and texture
ROSES –bred for colour, shape and scent.

14. SHEEP – bred for quality wool and lamb production
Other examples of selective breeding
DOGS – bred for speed and endurance
CATS – bred for best of breed shows
APPLES – bred for colour, taste and texture
ROSES –bred for colour, shape and scent.

15. SHEEP – bred for quality wool and lamb production
Other examples of selective breeding
DOGS – bred for speed and endurance
CATS – bred for best of breed shows
APPLES – bred for colour, taste and texture
ROSES –bred for colour, shape and scent.
LINSEED – bred for oil production

16. Selective breeding Advantages:
Produces an organism with the right features for a particular function.
Produces a more efficient and economically viable process for farming and horticulture.

17. Selective breeding Advantages:
Produces an organism with the right features for a particular function.
Produces a more efficient and economically viable process for farming and horticulture.
Disadvantages:
Reduced number of alleles in the population.
Reduced variation, so unable to respond to environmental change.
Can lead to other unexpected health problems.

18. Genetic Modification

19. Genetic Modification Genetic Modification
Genetic modification (GM) is the use of modern biotechnology to change the genes of an organism

20. Genetic Modification
Why GM?

21. Genetic Modification Why GM?
To improve crop yields, eg. larger tomatoes, more oil from linseed plants

22. To improve resistance to pests or herbicides, eg. Pyrethrum
Genetic Modification
Why GM?
To improve resistance to pests or herbicides, eg. Pyrethrum
To improve crop yields, eg. larger tomatoes, more oil from linseed plants

23. Genetic Modification Why GM?
To improve resistance to pests or herbicides, eg. Pyrethrum
To improve crop yields, eg. larger tomatoes, more oil from linseed plants
To improve the shelf-life of fast ripening crops such as tomatoes

24. Genetic Modification Why GM?
To improve resistance to pests or herbicides, eg. Pyrethrum
To improve crop yields, eg. larger tomatoes, more oil from linseed plants
To harness the cell chemistry of an organism, eg. human insulin
To improve the shelf-life of fast ripening crops such as tomatoes

25. GM Stuffed Dog (not really)
Genetic Modification
Genes are often transferred at an early stage of development (in both animals and plants) so they develop with the required characteristics
GM Stuffed Dog (not really)

26. GM Stuffed Dog (not really)
Genetic Modification
Genes are often transferred at an early stage of development (in both animals and plants) so they develop with the required characteristics
Characteristics can then be passed onto the offspring if the organism reproduces asexually, or is cloned.
GM Stuffed Dog (not really)

27. Genetic Modification
“describe the use of restriction enzymes to cut DNA at specific sites and ligase enzymes to join pieces of DNA together”

28. How do we change the genes of an organism?
Genetic Modification
How do we change the genes of an organism?

29. Genetic Modification How do we change the genes of an organism?
That’s a really good question – let’s start with an example

30. The production of human insulin by genetic engineering.
Genetic Modification
A hormone secreted by the pancreas, essential for the control of blood glucose.
The production of human insulin by genetic engineering.

31. Genetic Modification
A hormone secreted by the pancreas, essential for the control of blood glucose.
The production of human insulin by genetic engineering.
A Type 1 diabetes patient needs insulin injections to survive.

32. Genetic Modification
A hormone secreted by the pancreas, essential for the control of blood glucose.
Insulin medications were originally taken from cows, pigs or salmon.
The production of human insulin by genetic engineering.
A Type 1 diabetes patient needs insulin injections to survive.

33. Genetic Modification
A hormone secreted by the pancreas, essential for the control of blood glucose.
Insulin medications were originally taken from cows, pigs or salmon.
The production of human insulin by genetic engineering.
A Type 1 diabetes patient needs insulin injections to survive.
Human insulin first synthesised by genetic engineering in 1978.

34. Genetic Engineering – The Process
Chromosome
Human cell
Part of a human chromosome
Human insulin gene

35. Genetic Engineering – The Process
Chromosome
The gene for insulin production is ‘cut out’ of the human chromosome using restriction enzymes
Human cell
Part of a human chromosome
Human insulin gene

36. Genetic Engineering – The Process
Restriction enzymes, found naturally in bacteria, can be used to cut chromosome (DNA) fragments at specific points.
Chromosome
The gene for insulin production is ‘cut out’ of the human chromosome using restriction enzymes
Human cell
Part of a human chromosome
Human insulin gene

37. Genetic Engineering – The Process
Chromosome
The gene for insulin production is ‘cut out’ of the human chromosome using restriction enzymes
Human cell
Part of a human chromosome

38. Genetic Engineering – The Process
Bacteria are prokaryotic micro- organisms. They do not have a distinct cell nucleus
Bacterium
Bacterial DNA
Plasmid = small DNA molecule, separate from the chromosomal DNA

39. Genetic Engineering – The Process Genetic Engineering – The Process
Another restriction enzyme is used to cut open a ring of bacterial DNA.

40. Genetic Engineering – The Process Genetic Engineering – The Process
Another restriction enzyme is used to cut open a ring of bacterial DNA.
Other enzymes (ligase enzymes) are used to insert the piece of human DNA into the plasmid.

41. Genetic Engineering – The Process Genetic Engineering – The Process
Another restriction enzyme is used to cut open a ring of bacterial DNA.
Ligase enzymes are enzymes that catalyze reactions which make bonds to join together (ligate) smaller molecules to make larger ones.
Other enzymes (ligase enzymes) are used to insert the piece of human DNA into the plasmid.

42. Genetic Engineering – The Process
Plasmid now reinserted into a bacterium which starts to divide rapidly.
VAT

43. Genetic Engineering – The Process
As it divides it replicates the plasmid, and very soon there are millions of them, each with the code to make insulin.
VAT

44. Genetic Engineering – The Process
Commercial quantities of insulin are then produced.
VAT

45. Genetic Engineering – The Process
The vector (the carrier) may be a virus rather than a bacterial plasmid. The viral vector is also known as a virion.

46. Genetic Engineering – The Process
The viral vector is able to transport the DNA directly into the nucleus of another cell.
The vector (the carrier) may be a virus rather than a bacterial plasmid. The viral vector is also known as a virion.

47. Genetic Engineering – The Process
The viral vector is able to transport the DNA directly into the nucleus of another cell.
After insertion of the DNA the protein is then produced using the cells’ own mechanism.
The vector (the carrier) may be a virus rather than a bacterial plasmid. The viral vector is also known as a virion.

48. Genetic Engineering – The Process
Human insulin was the first commercially available protein produced by recombinant DNA technology.

49. Genetic Engineering – The Process
Recombinant DNA is the general name for taking a piece of one DNA strand and combining it with another strand of DNA.
Human insulin was the first commercially available protein produced by recombinant DNA technology.

50. Genetic Engineering – The Process
Large amounts of human insulin can be manufactured from genetically modified bacteria that are grown in a fermenter

51. Genetically Modified Crops
“Major doubts have been raised over the safety of GM foods by a new study ..”
“The Daily Mail’s Frankenstein Food Watch campaign has long highlighted problems with the lack of rigorous safety assessments for GM crops and food.”

52. Genetically Modified Crops
Most developments are in the experimental or trial stages. In the UK, GM crops are grown only on a trial basis.

53. Genetically Modified Crops
Most developments are in the experimental or trial stages. In the UK, GM crops are grown only on a trial basis.
Developed particularly for insect / pest resistance

54. Genetically Modified Crops
Most developments are in the experimental or trial stages. In the UK, GM crops are grown only on a trial basis.
Bacterium (Bacillus thuringiensis) has a toxin that kills caterpillars and insect larvae. Gene for this toxin implanted in some plant species using a bacterial vector.
Developed particularly for insect / pest resistance

55. Genetically Modified Crops
Most developments are in the experimental or trial stages. In the UK, GM crops are grown only on a trial basis.
Plants produce the toxin and have shown increased resistance to attack by insect larvae. Unfortunately there are signs that insects are developing immunity to the toxin.
Bacterium (Bacillus thuringiensis) has a toxin that kills caterpillars and insect larvae. Gene for this toxin implanted in some plant species using a bacterial vector.
Developed particularly for insect / pest resistance

56. Genetically Modified Crops
Most developments are in the experimental or trial stages. In the UK, GM crops are grown only on a trial basis.
In 2002 half the cotton grown in China was genetically modified to produce a substance poisonous to the cotton bollworm, a pest of cotton crops.
Developed particularly for insect / pest resistance

57. Genetically Modified Crops
Most developments are in the experimental or trial stages. In the UK, GM crops are grown only on a trial basis.
Benefits of the GM cotton are a reduction in pesticide use, and increase in yields and profits, and health benefits to workers (no more spraying of pesticides).
In 2002 half the cotton grown in China was genetically modified to produce a substance poisonous to the cotton bollworm, a pest of cotton crops.
Developed particularly for insect / pest resistance

58. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield

59. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour

60. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease

61. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield Can offer more nutritional value and better flavour Inbuilt resistance to pests, weeds and disease Crops require less herbicides and pesticides

62. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease
Crops require less herbicides and pesticides
foods are more resistant and stay ripe for longer, so improving shelf life.

63. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease
Crops require less herbicides and pesticides
foods are more resistant and stay ripe for longer, so improving shelf life.
more GM crops can be grown on relatively smaller parcels of land.

64. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease
Crops require less herbicides and pesticides
foods are more resistant and stay ripe for longer, so improving shelf life.
more GM crops can be grown on relatively smaller parcels of land.
Exact insertion of the genes is still a ‘hit or miss’ process.

65. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease
Crops require less herbicides and pesticides
foods are more resistant and stay ripe for longer, so improving shelf life.
more GM crops can be grown on relatively smaller parcels of land.
Exact insertion of the genes is still a ‘hit or miss’ process.
GM food will end food diversity if everyone grows same standard crops.

66. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease
Crops require less herbicides and pesticides
foods are more resistant and stay ripe for longer, so improving shelf life.
more GM crops can be grown on relatively smaller parcels of land.
Exact insertion of the genes is still a ‘hit or miss’ process.
GM food will end food diversity if everyone grows same standard crops.
GM crops could cross-pollinate with nearby non-GM plants and create ecological problems.

67. Genetically Modified Crops
Advantages
Disadvantages
GM crops more productive and have a larger yield
Can offer more nutritional value and better flavour
Inbuilt resistance to pests, weeds and disease
Crops require less herbicides and pesticides
foods are more resistant and stay ripe for longer, so improving shelf life.
more GM crops can be grown on relatively smaller parcels of land.
Exact insertion of the genes is still a ‘hit or miss’ process.
GM food will end food diversity if everyone grows same standard crops.
GM crops could cross-pollinate with nearby non-GM plants and create ecological problems.
Herbicide-resistant and pesticide-resistant crops could give rise to super-weeds and super-pests that would need newer, stronger chemicals to destroy them.

68. Transgenic Species
“understand that the term ‘transgenic’ means the transfer of genetic material from one species to a different species”

69. Glofish, the first transgenic animals to be sold as pets.
Transgenic Species
Transgenic = an organism whose genetic material has been altered using genetic engineering techniques.
Glofish, the first transgenic animals to be sold as pets.

70. Glofish, the first transgenic animals to be sold as pets.
Transgenic Species
Glofish – fluorescence gene from a jellyfish inserted into zebrafish embryo. Fish are now brightly fluorescent in both natural white light and UV light.
Glofish, the first transgenic animals to be sold as pets.

71. Transgenic Species
An anti-blood-clotting agent used in heart surgery has been produced in the milk of transgenic goats. The product is in the final stages of clinical trials.

72. Transgenic Species
The gene for an enzyme, alpha-anti-trypsin, which blocks the action of the protease enzymes in the lungs of people suffering from inherited emphysema, has been transferred to sheep.

73. Transgenic Species
The gene has been inserted into milk producing cells in sheep mammary glands. The sheep now produce the enzyme in their milk, from which it can be separated and purified.

74. Transgenic Species
Transgenic organisms can also pass the modification on to future generations by breeding with other members of the same species.

75. End of Section 5 Lesson 2 In this lesson we have covered:
selective breeding
genetic modification
genetic engineering
GM crops
transgenic species