5.15a

5.14 Humulin

5.13b Hosting recombinant DNA

5.13a Recombinant DNA

5.11

5.10

5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

Fish are attractive product for farmers as they have low fat and high protein. Also they are efficient at turning their nutrient to fish mass.

Advantages:

·      Fish farming allows us to control the quality of water

·      We can control predators

·      We can reduce pests and other forms of disease

By controlling all of these factors we contribute to the increase in the yield of fish.

Disadvantages:

·      However when you have a high density of fish, then the possibility is for the transition of disease. Because of this some fish farmers have taken to using antibiotics this is a concern for human health

·      The abundance of fish within the fish farms increase the abundance of pest, so some fish farmers have taken to using pesticides, this also is a cause for concern among humans. 

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

The industrial fermenter is the reaction vessel in which fermentation occurs, it is usually made out of steel or copper. There is steel jacket in which there is normally another steel jacket inside, and in between the two, there will be water, which is cooling jacket. Once the fermentation happens it will produce heat and the water will cool down the water so that the reaction occurs at the optimal temperature.

The fermenter will need to be cleaned and that is why there is an inlet where steam will enter and then the steam will sterilizes the fermenter between fermentations. The steam cleans the tanks out.

Within the fermenter there will be a heating plate to raise the temperature, the combination of the heater and the cooling jacket, allows the fermenter to keep optimum temperature for fermentation.

So that fermentation can occur nutrient has to be added to the tank, so there would be a tap into the fermenter. The nutrients will act as food for the microorganism. There would also be a temperature probe in the tank in order to monitor the temperature, to see whether you needed to use the heating plate or the cooling jacket. The reaction would also require the addition of the microorganisms so there would be another tap for that.

You would also need a pH probe in order to keep the conditions at the optimum rate of reaction. 

You also need a way of stirring the reaction, and this is done to agitate the mixture stopping it from clumping and spreading the microorganism.

You would also need a way drain off the product. Which would then go off to process called down stream processing, which involves purification.

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

5.5 understand the role of yeast in the production of beer

5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants

Large amounts of crops of the same type tend to be susceptible to pests, which use the crops for food. this reduces the amount of crop yielded and therefore the farmers profit is reduced.

To overcome this farmers use two solutions:

1. Pesticides 

Advantages

.Pesticides are chemicals so they are easy to obtain

.Easy to apply 

.Very effective

Disadvantages 

. Pesticides can be toxic, they could kill other animals and plants, then the pests they are aimed to kill.

   -pesticides can also be harmful to humans

.Bio accumulation  is when pesticides build up through the food chain causing problems for animals higher in the food chain.

.Mutation in the pests often leads to resistance which means pesticides have to be applied in higher concentration therefore the pesticide is more toxic or the pesticide no longer works and then the farmers have to find alternative pesticides 

2. Biological Control 

Advantages

. No toxic chemicals  

. less  impact on the wildlife, or humans

Disadvantages 

. Not 100% effective
. Can be difficult to control, there is a danger that the introduced species would start preying on a    alternative prey so it will not die out
. It is difficult to match a predator to prey
. It can take a long time 

5.3 understand the use of fertiliser to increase crop yield

To increase the growth of a plant, farmers do this by the application of fertilisers to the soil and these normally take the form of nitrates or phosphates and frequently a compound of both. These compounds go down into the soil and are taken up by the root structure and then moved in the transpiration stream up t the leaf and are used ion the leaf to for the construction of –when they are nitrates will form proteins and the phosphates are involved in things like DNA and membrane structure.

The fertilisers can be divided in to 2 groups: the organic and the artificial.

The organic group are produced from animal waste on farms ant they usually take the form of cow faeces and collected by the farmer often it goes through the process decomposition and fermentation and forms a compound called slurry and this is applied to the fields and givens the crops a supply of nitrate and phosphate.

The artificial fertilisers take the form of chemicals, which are synthetically produced like potassium nitrate and ammonium nitrate. These can be brought by the farmer and applied to the field and they will form a solution and in the soil water and this will release the nitrates, which will also produce growth.  

5.2 understand the effects on crop yield of increased carbon dioxide and increased temperature in glasshouses

5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops

Greenhouses, sometimes called glasshouses, provide the right conditions for plants to grow for several reasons:

The transparent material allows sufficient natural light for photosynthesis during the summer months, while additional lighting gives a 'longer day' during the winter.

The greenhouse effect also happens in greenhouses. Short wave radiations entering the greenhouse  becomes longer wave radiation as it reflects off surfaces. This longer wave radiation cannot leave as  easily so the greenhouse heats up.

Burning fuels to raise the temperature when the external heat is too low also produces carbon dioxide and water vapour. the water vapor maintains a moist atmosphere and therefore reduces the loss of water by transpiration. The carbon dioxide is a raw material of photosynthesis.

Glasshouses also protect plants from things such as strong winds and heavy rain.

 Also, growing plants in a hydroponic culture provides exactly the right balance of mineral ions for the specific crop being grown.

2.89 understand the sources, roles and effects of the following hormones: ADH, adrenaline, insulin, testosterone, progesterone and oestrogen.

2.88 describe the role of the skin in temperature regulation, with reference to sweating vasoconstriction and vasodilation

Sweating, vasodilaton and casoconstriction, hair erection, and  shivering act together to keep the body temperature to within a few tenths of a degree to the normal 37 degrees Celsius.

If the body temperature is too hot, (this can be detected by he hypothalamus) the sweat glands produce greater amounts of sweat. This liquid is secreted onto the surface of the skin. When a liquid is evaporated it turns into a gas, and this change requires energy called the latent heat of vapourisation. When sweat evaporates, the energy is supplied by the bodies heat cooling the body down.

Also, in cold conditions the hair erector muscles at the base of the hair on you skin, contract and the hairs are pulled upright. this traps a layer of air next to the skin, and since air is a poor conductor of heat, this acts as insulation

There are tiny blood vessels called capillary loops in the dermis. Blood flows through these loops radiating heat to the outside, and cooling the body down. if the body is too hot small arteries (arterioles) leading to the capillary loops dilate (widen). This increases blood flow to the skins surface and is called vasodilation.

In cold conditions the opposite happens. the arterioles leading the the surface capillary loops constrict ( become narrower) and blood flow to the skin id reduced, so that less heat is lost. This is called vasoconstriction.

Shivering also takes place in cold conditions, it is when the muscles relax and contract rapidly. This generates a large amount of heat.

2.87 understand the function of the eye in focusing near and distant objects, and in responding to changes in light intensity

2.86 describe the structure and function of the eye as a receptor

2.85 describe the structure and functioning of a simple reflex arc illustrated by the withdrawalof a finger from a hot object

2.85 describe the structure and functioning of a simple reflex arc illustrated by the withdrawalof a finger from a hot object

The stimulus (the finger touching the hot object) is detected by temperature or pain receptors in the skin. these generate impulses in sensory neurones. the impulses enter the central nervous system through a part of the spinal cord called the dorsal root. in the spinal cord the sensory neurones connect by synapses with short relay nerones, which in turn connect with motor neurones. the motor neurones emerge from the spinal cord through the ventral root, and send impulses back out to the muscles of the arm. these muscles then contract pulling the arm and therefor the finger away from the harmful stimulus. 

2.84 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses

2.84 understand that stimulation of receptors in the sense organs sends electrical impulses along nerves into and out of the central nervous system, resulting in rapid responses


the impulses that travel along a neuron are not an electrical current they are a result of the movement of ions out an in of the neurone. these impulses can travel at speeds between 10 and 100 m/s which is fast enough to produce a rapid response. 

2.83 recall that the central nervous system consists of the brain and spinal cord and is linked to sense organs by nerves

The central nervous system consists of the brain and the spinal cord.
The central nervous system or CNS is a intricate network of nerve cells and nerve fibers throughout the body. Its function is to interpret, store, and respond to information received from inside the body and outside the body. The CNS is responsible for processing information gathered from the rest of the nerves and transmitting instructions to the body. Messages to and from the CNS are carried by the nerves of the nervous system.

2.82 describe how responses can be controlled by nervous or by hormonal communication and understand the differences between the two systems

2.77b Thermoregulation

2.77a Thermoregulation

2.76 Sensitivity