5.20 - Cloned transgenic animals

- animals that are cloned are genetically identical 
- transgenic refers to an organism with DNA from 2 or more organisms 


- commercial production of antibodies 


-cow - obtain egg cell 
- human - take a cell - using restriction enzymes, going to take the 'gene antibody production' 


1. in the egg cell - first step is to knock out the cow antibody production gene 
2. Add human gene - transfer from human cell
3. Cows cell is then developed by mitosis to form a clone of cells - embryo - transferred to the surrogate mother 
4. These then produce genetically identical calves 


In this example, the gene for antibodies is expressed and the antibodies are then collected in the milk - this is the human antibody not cow - large commercial scale

5.19 - Mammal Cloning

sheep 1 = Original --genetically identical to clone--> dolly 


- need to obtain genetic info from 1. - done by removing a diploid cell (has a full set of genetic information) 
- at the same time - need to obtain a cell that has a tendency to divide 
sheep 2. completely different animal - has been treated with hormones to produce eggs 
- egg cell - tends to divide 
- do not want the genetic information of the egg and so it is removed (enucleated) 


- take the cell with the genetic information (want to copy) and the cell from the egg which wants to divide and FUSE them together 
- when fusing them together we have the genetic information and a cell that wants to divide 
- the combination of the two results in many cell divisions (like mitosis) to form a ball of cells (blastula - embryonic sheep - genetically identical to sheep 1) 


-embryo (blastula) of sheep 1 is placed into another sheep 3 - which is the surrogate mother 
- the embryo will grow into a fetus 
- this fetus is the clone of sheep 1 and is what we call dolly - it is genetically identical to sheep 1 
- this means they are a clone, even though their age is very different 

5.18 - Commercial plant growing

- Plant has characteristics which are considered commercial so therefore desirable and so want to make copies of this plant 


- sexual reproduction causes loss of qualities that make it valuable as a commercial plant 


- use a cloning technique to get many plants of the same quality
- commercially, that keeps the product the same so that they can be sold
- technique used is micropropagation 

5.17 - Micropropagation

Looking for characteristics of a plant that are desirable - want to produce more plants of the same kind 


if sexual reproduction - the offsprings will differ and so we have to use micropropagation


Process: 
- Take tissue from the shoot tip or the roots 
- Aseptic conditions (free from contamination) 
- Cut the tissue into many small parts 
- Transfer tissue to petri dish - contains nutrient agar - variety of minerals, rooting compounds and other plant hormones - to encourage growth into small clones of original plants 


- In this process you make many clones of the original plant - all genetically identical to the original plant 

5.16 - Transgenic Organism

- video 5.13: Bacterial cell became transgenic because it had the bacterial DNA and Human DNA (plasmids held Insulin gene)

- this is a transgenic organism 

- video 5.15: Maize DNA and transferred into it was the BT gene 

- this is a transgenic organism 

5.11 - Breeding Animals

- Animal: cow 

- desired characteristic: milk yield 

- the farmer would collect all the milk but take the cows that produce 150ml to be the breeding cows in the next generation

- the farmer then selects the cows with high yield to become the breeding cow in the next breeding population 

- as we progressively select, we are able to change the desired characteristic to develop it - by selective breeding 

- for this to work, milk yield must be genetic (under the control of genes) 

5.10 - Breeding plants

- The number of rice grains is under the control of the genes 

- The farmer wants to increase the number of rice grains per plant to then increase the yield

- The farmer notices that some plants have 6 grains per stem, others have 8 grains per stem and others have 10 grains per stem 

- The farmers decision is to harvest the grains with 6 or 8 but use the 10 grains for planting 

- In the next generation of rice he notices that the grains are increased to 8 grains per stem, 10 grains per stem and 12 grains per stem and so he harvest the 8 and 10 grains and selects the 12 grains for planting and breeding 

- In this way, the number of grains of rice found on the plant will gradually increase which will increase the yield 

- This is an example of selective breeding

5.12 - Restriction and Ligase enzymes

1. Restriction enzymes 

- able to cut DNA at a particular location 

- this location is identified by the base sequence 

2. DNA Ligase

- able to join the DNA back together

5.15 - Genetically Modified Plants

1. Maize - damaged by the larvae of the European Corkborer - can cause up to 20% loss of crop yield 

2. Existence of a bacterium - BT 

- chromosome of BT shown - on the chromosome there is a gene

- when this gene is switched on it produces BT toxin - known to kill the Corkborer larvae. 

3. First step to get the toxin into the Maize to protect it from the European Corkborer 

- take restriction enzymes to the gene of the BT - take the gene out to leave the BT gene for the toxin 

4. Has to be transfered to the cells of the maize plant 

- A 'gene gun' is used to do this - involves taking tiny particles of gold and coating them in the BT gene 

- They are then fired at high velocity at the plant cell 

- This introduces them into the plant cells interior 

- The plant cell then gets the gene 

- Maize cell now has BT gene so when it is switched on it can make the BT toxin which means they can kill the larvae

- This gives the Maize resistance to damage caused by the cork borer

5.14 - Humulin

- Humulin - Human Insulin 

- Bacterial cell (e.g. E Coli) has been transformed by the addition of recombinant DNA 

- culture (large population) of the bacterial cell would be injected into the fermenter 

- the fermenter must provide the culture with nutrients, control of temperature, pH and the gases inside the fermenter

- by creating the optimal temperature for bacterial growth - you will see the population increase 

- the Bacteria switches on the gene for insulin and manufactures the protein Insulin from the provided Amino acids (in the nutrients)  

- then the product must be removed for purification - downstream processing (for human use) 

- the genetically engineered human insulin is called Humulin

5.13b Hosting recombinant DNA

- Recombinant DNA (human gene and Bacterial Plasmid) 

- transfer this structure to the host cell (virus) 

- inside the virus - nucleic acid (e.g. DNA or RNA) 

- around the virus - protein shell (capsid) 

- first thing - remove the nucleic acid from the virus to leave the capsid

- The plasmids are taken up by the virus. The virus acts as a vector for the recombinant DNA 

- This helps to transfer the DNA into the host cell 

- This virus is known as a phage (infects bacterial cells) 

- able to attach to the cell membrane of the bacteria and insert the recombinant DNA into the host cell

- at the end of the process: Bacterial cell which contains the recombinant DNA (including the human gene, insulin) 

- The bacteria has its own DNA plus the DNA from another organism - this combination is known as 'transgenic' 

5.13a - Recombinant DNA

1. Plasmid 

- found in bacterial cells 

- ring of DNA, particularly small and don't carry very many genes 

2. Virus 

- has a protein shell (caspid) 

- inside - nucleac acid - DNA or RNA

- does not have any other structures such as nucleus, cytoplasm

3.  Human Chromosome 

- made of DNA 

- shown gene  is Insulin - Hormone that controls blood sugar levels

- Restriction enzyme is selected so that it can cut the DNA  and take out the Insulin

- having cut the gene --> take the plasmid and cut it with the same restriction enzyme (so it is the same jagged shape) 

- the ring structure is now broken 

- introduce into the cut plasmids, the human insulin gene 

- both the plasmid and the insulin is composed of DNA 

- plasmid then has the insulin in it 

- To complete the process DNA ligase must be added to join the DNA 

- This process of the Human gene and the plasmid DNA is known as Recombinant DNA

5.9 - Fish Farming

Fish are an attractive product to farmers as they: 
- have low fat and high protein 
- are efficient at turning their nutrient into fish mass 


Fish Farming Advantages: 
- allow the control of the quality of water - clean 
- can control predators 
- Can produce and control pests 
- Can control diseases 
By controlling all these factors it contributes to an increase in yield of fish. 


However, where there is a high density of fish, the possibility of transmission of disease increases. 
- This has caused fish farmers to begin using antibiotics
- The abundance of fish within the fish farm makes pests common and so some farmers have begun to use pesticides 


Both these contribute to the cause of concern for humans.  

5.8 - Fermentation

5.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including aseptic precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of microorganisms

5.7 - Lactobacillus in Yoghurt

5.7 understand the role of bacteria (Lactobacillus) in the production of yoghurt

5.6 - Carbon Dioxide Production

5.6 describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions

5.5 - Beer Production

- yeast in beer production 
beer is made of : 
starch --- Amylase (germination of seed - known as 'malting') ----> Maltose ---Maltase---> Glucose 


Starch comes from: 
- Barley Seeds 
- Wheat Seeds 
- Rice (asian beers) 


Glucose comes from Starch 


Glucose --anaerobic respiration (yeast supplies enzymes for conversion) ----> ethanol + CO2 + Hops 


Hops flavors the beer (in plants)  

5.4 - Pesticides and Biological Control

- Large fields of crops all at the same time - Monoculture 
- Monoculture - very susceptible to pests - they use the crop as a food source - this reduces the productivity of farming (food and financially)


1. Pesticides - chemicals - designed to kill the pest 


Advantages: 
- Chemicals - easy to obtain  
- Easy to apply - spray 
- Very effective 


Disadvantages: 
- Toxic - may kill other plants and animals other then the pests and may be harmful to humans 
- Bio accumulation - pesticide builds up through the food chain causing problems for higher trophic levels (DDT) 
- Mutation in the pest leads to resistance - pesticide must then be applied at higher concentrations which then make it more toxic





2. Biological Control 
Example in Australia 

Advantages: 
- No toxic chemicals involved 
- Less impact on man/wildlife 


Disadvantages: 
- Not 100% effective 
- Difficult to control - always a danger that the introduced species will find an alternative prey. e.g. Cane toad (australia) 
-  Difficult to match a predator to the prey. May not be able to find an animal that can remove the pest

5.3 - Fertilizers

- achieved in farming by fertilizers in soil - these take the form of nitrates or phosphates (can be a combination of both) 
- go down into the soil and are take up by the root structure - go up to the leaf and is then used for the construction of: 
nitrates --> proteins
phosphates --> DNA and membrane structure 


Fertilizers can be split into two groups 
Organic and Artificial 

Organic: 
- produced from animal waste on farms, cow faces --> collected by the farmer and goes through decomposition and fermentation and forms slurry (gives nitrate and phosphate to promote growth) 


Artificial: 
- Chemicals which are produced. Such as Potassium nitrate and ammonium nitrate --> go into solution in the soil water --> release nitrate and promotes growth like an organic fertilizer 

Eutrophication - problem which arises through the use of artificial fertilizers 

5.2 - Crop Yield

Related to the: 


rate of photosynthesis - this is the combination of CO2 and water with light (enzyme) to form glucose (starch) and oxygen 
- Increasing the concentration of CO2, CO2 is the substrate 
- Shown in graph - rate of ps will increase the yield until the greatest yield point 

Temperature - Increasing 
- Shown in graph - rate of ps increases as temperature increase up to an optimum (peak)  temperature 


Increasing temperature in a greenhouse can also avoid frost damage and provide constant temperature - both contribute to increase in yield 

Both have limits (optimums)