Cloning of Mammals 5.19

1. Dolly will be cloned and its clone will be genetically identical to it. 
2. To obtain genetic information, a cell would have to be removed from clone 1. 
3. the nucleus of the cell contains all the genetic information of the animal. 
4. From clone 2, we get the egg cell which tends to divide. 
5. However, we do not want the genetic information in clone 2's case therefore we take it out (enucleate it). 
6. We take the cell with the genetic info which we do wish to copy and the cell which wants to divide, and fuse them together. 
7. Now we have the genetic info and the cell which wants to divide. 

5.14 Humulin

1. we are looking at the production of human insulin in a fermenter. 
2. In 5.13b we saw how this bacterial cell here has been transformed by the addition of recombinat DNA
3. The black circle represents the plasmid DNA 
4. Th yellow dot represents the human insulin gene

1. A culture, a large population, of these bacteria will be injected into the fermenter 
2. It will be necessary to provide this culture nutrients, control the temp and pH and gases in the fermenting chamber. 
3. By creating these optimal temperature for bacterial growth we will see population increase and we will see the bacteria switch on the insulin gene and manufacture the protein insulin.  
4. The bacteria inside the fermenter will manufacture the insulin protein from the nutrients provided (amino acids).
5. It will then be necessary to remove the product and carry out purification of the insulin. 
6. Downstream processing is used to purify the insulin for human consumption. 
7. The genetically engineered insulin is called humulin

5.9 Fish farming

1. Fish are an attractive product for farmers as they have low fat and high protein. 
2. Fish efficient at turning their nutrient into fish mass 

Advantages of fish farming 

1. fish farming will allow us to control the quality of water.
2. We can control predators
3. we can reduce pests and other forms of disease. 
4. By controlling all the factors above we're contributing to an increase in a yield of fish. 

disadvantages: 

1. However when you have a high density of fish the possibility is for the transmission of disease. 
2. because of this some farmers take antibiotics which is of concern to human health. 
3. the abundance within the fish farm, makes pests common therefore farmers use pesticides. This also is harmful to humans. 

5.4b Biological control

1. In Australia the prickly pair cactus of north america was introduces to garden which escaped into the countryside and the prickly pair cactus flourished under the Australian climate. 
2. However, it started taking up a lot of the agricultural land therefore it was important to get rid of it. 
3. An alien species, a moth (cactoblastis), was introduced, which feeds on the cactus. This moth had no competitors and therefore it was able to eat away at the cactus and remove it from the land. 
4. This is an example of controlling the pest. In this case, the cactus is the pest, which is eaten away by the herbivore. This is called biological control. In this case, we're not using pesticides.
5. Advantages of biological controls: 
1. No toxic chemicals involved means it has less impact on man or on wildlife.
6. Disadvantages 
1. Not a 100 percent effective 
2. There is always a danger that the introduced species will find an alternative prey on which to feed and will not die out once the pest is removed therefore it is difficult to control.
3. It is difficult to match a predator to the prey. you can;t actually find a suitable predatory herbivorous animal to remove your pest. 

5.4 pest control

1. monoculture- a large field of crops all of the same type. eg fields of rice, potatoes. 
2. when we have a monocuture they tend to be very susceptible to pests. 
3. pests use the crop as their own food source. In doing so, it reduces the productivity in farming. E.g. loss of food and financial impact on the farmer.
4. To overcome this, you should use pesticides (chemicals)
5. Advantages of using pesticides: 
1. pesticides kill pests
2. They are easy to obtain because they are chemicals 
3. They are easy to apply 
4. They are very effective 
6. Disadvantages: 
1. Many of these chemicals present in pesticides are  very toxic therefore they will kill other plants and animals other than the pests. They can also be harmful to humans 
2. bioaccumilation- pesticide builds up in the food chain and builds problems for animals in the higher trophic levels. 
3. Mutation in the pests often leads to resistance therefore the pesticide must be applied in higher concentration, it is more toxic or it no longer works. 

5.3 Fertilisers

1. We're looking at the Use of fertilisers to increase crop yield 
2. Lets say we have a plant and we want to increase the growth of the plant. This is achieved by farming by the application of fertilisers to the soil and these normally take the form of nitrates or phosphates. 
3. These compounds go down into the soil and are taken up in the root structure and then moved in the transpiration stream up to the leaf and used in the leaf for the construction of proteins (nitrates) or DNA/ membrane structure (phosphates). 

1. fertilisers can be divides into two groups, organic and artificial fertilisers. 
2. Organic group are produced from animal waste on farms. this usually takes the form of cow faeces. 
3. the faeces go through the process of decomposition and fermentation and forms a substance known as slurry. This is applied to the field, giving the crop plant a supply of nitrate and phosphate to promote growth. 
4. The artificial fertilisers take the form of chemicals which are synthetically produced. Two well known ones are potassium nitrate and ammonium nitrate. They will go into solution in the soil water once applied to the fields.
5. This will release nitrates which will also promote growth. 
6. eutrofication occurs due to the use of artificial fertilisers. 

5.2 Crop Yield

1. We're looking at the increase of crop yields due to higher levels of carbon dioxide and higher temperatures. 
2. This can be related to the rate of photosynthesis. 

Increasing concentration of Carbon Dioxide: 

1. Carbon dioxide is the substrate within photosynthesis. 
2. The rate of photosynthesis will increase therefore we'll have a higher yield up to a point. 

Increasing the temperature 

1. Yield increases until we reach the optimum temperature. 
2. increasing temperature in a glasshouse also has other effects such as avoiding frost damage and provide  constant temperature, contributing to the yield growth. 

5.1 Glasshouses

1. Glass houses (greenhouses)- are constructed on a framework, like a house, all their surfaces are glass, allowing light to penetrate through to the interior. 

1. Ploythene tunnels- also framework with polythene over the surface. Polythene allows light to penetrate through. Associated with things like market gardening. Can be taken down and replaced. Used in cheaper countries. 

Glasshouse:

1. Firstly, we have solar radiation which is our initial source of energy in the form of light. 
2. The light is able to penetrate through the glass to the internal surfaces. 
3. The light is absorbed by surfaces inside the glasshouse. eg the soil the wooden bench surfaces or the plants
4. these surfaces re-emit this energy as heat. 
5. The heat warms the air, raising its average kinetic energy (the temperature increases)
6. The warm air is trapped. Generally it would cool at the upper surfaces and then sink to the floor again to be rewarmed by the surfaces. 

How does this cause an increase in crop yield?

1. Warm air in the glasshouse increases crop yield 
2. The higher temperature in the glasshouse, lead to closer or optimum temperature for enzyme reactions including photosynthesis. 
3. It provides constant temperatures throughout the growing year therefore we have constant production. 
4. The prevention of loss of water vapour. Crops don't dry out. 
5. Able to avoid frost damage to seedlings in the spring time. 
6. Glasshouses are often warmed by the burning of fossil fuels. This leave to two effects. 
1. Increase in Carbon dioxide, which means we have increased the concentration of the substrate for photosynthesis.  
2. burning of the fossil fuels also results in the production of ethene. This gas stimulates fruit ripening. 

2.84-2.85 Nerve Impulses and Responses

Electrical Impulses: is a method of transporting information of environmental change from the receptor to the coordinator in order to receive a response.

1. Impulses are sent to the coordinator from the receptor. 
2. While making a decision, receptors are affected by an environmental change, electrical impulse is then sent to the Central Nervous system through the sensory nerves. The brain then coordinates a response. 

An uncoordinated response: A reflex, Example- withdrawing your hand after touching something really hot

1. Pain receptor detects the hot temperature (stimuli)
2. Sensory nerve sends electrical impulse to the brain. 
3. The motor nerve sends signals to the effector which is the muscle in this case. The muscle then contracts and hand is withdrawn. 

2.83 Central Nervous System

1. The central nervous system is made up of the spinal cord and the brain. All the nerves branch out from the spinal cord. 
2. The Central Nervous System allows the body to respond to any changes in the environment.

How the CNS works: 

1. Nerve impulses from the receptors travel through sensory nerves till they reach the spinal cord and brain. 
2. The response is coordinated by the brain 

2.82 Communication

Nerve system 

1. motor nerve-The orange/yellow part in the nerve would be embedded in the spine 

1. The end is connected to an effector, most likely a muscle 
2. The electrical impulse or nerve impulse is carried down the orange structure from the cell body to the synaptic knob, where it connects to the muscle. 
3. The long structure is known as the axon. 
4. In mammals, the axon is surrounded by schwann cells, which contain a lot of fat. They form a myelin sheath. 
5. The effect of this is to increase the speed of nerve conduction. 

Endocrine System 

1. The endocrine system involves an endocrine gland. 
2. This produces hormones, could be protein or steroids. They are produced and manufactured in endocrine glands an e.g. of this would be adrenal gland. 
3. The hormone is secreted into the blood.This will travel through the blood stream in order to get to its target organ or target tissue on which it will have an effect. 
4. Hormones can have multiple targets and can bring about multiple effects.
5. Communication based on nerves- Nerve impulse is fast
6. Communication based on hormones- Nerve impulse is slow. 

2.77b Thermoregulaation

1. here we are developing the idea of the control of body temperature. 
2. Negative feedback loop- method of control and maintaining constant conditions. Keeps the human body at about 37 to 38 degrees.
3. In order for this to work we have a receptor- hypothalamus- region of the brain, responds to stimulus-temperature of blood. 
4. Body temp feeds into the brain and is compared to the theoretical level of control. 
5. If the body temp needs to be increased or decreased, bought about through the action of the effector such as the skin.
6. The response to this would either be an increase or decrease in body temperature. 
7. This would intern feedback to the hypothalamus. 
8. One of the major components of skin are sweat glands and the capillary networks (allows blood to move closer or further away from the skin)
9. x axis represents time and y axis represents temperature. 

1. If the body temp increases the input into the hypathalamus stimulates responses in the skin which bring about cooling, done through sweating or the flow of blood to the surface of the skin through the blood vessels which dilate (widen) in order to get more blood flow to the surface. 

1. This further increases the exchange of heat to the outside of the heat through radiation and evaporational sweat.
2.  this brings about cooling of the blood which returns the body temp to fixed level. 
3. Body temperatures can fall in a cold environment. 
4. When the body temperature decreases, this feeds into the hypothalamus which then swicthes on and brings about regulation to increase the body temperature such as shivering, vasoconstriction or raised hair

2.77a thermoregulation

1. homeostatis-the conditions are kept same or constant. 
2. Homeothermic- the idea of maintaining the same temperature. 
3. In mammals for instance, when the environmental temperature increases or decreases, their body temp remains constant, They are called homeothermic organisms and carry out the process of thermoregulation. 
4. the reason why mammals wish to maintain their body temperature: 

1. 
   
2. As you can see on the x axis we have the temperature and on the y axis we have the rate of reaction (enzyme ctalysed reaction). 
3. The max rate of reaction is achieved at the optimum temperature.
4. The optimum temp for the enzyme reaction is approximately the same temperature at which the mammals maintain their body conditions 

2.76 Sensitivity

1. Organisms are able to respond to changes in the environment
2. The types of changes in the environment include changes in light levels, temperature, pressure levels and chemicals. 
3. In order to detect these changes in the environment organisms have receptors.
4. In order to respond to the changes in the environment organisms have effectors such as muscles and glands. 
5. It is the response that ensures that the organism is able to survive the changes in the environment.