5.4b Biological control

• Biological control of pests simply means an introduction of a species that could terminate the pests
• Advantages of Biological control is no toxic chemical and less impact on the wild life
• Disadvantages to biological control is that it is not 100% effective, it is difficult to control and it is difficult to match the predator to the prey. Also new pests may be created in the process of trying to get rid of the original pest eg. cane toads

5.4a Pesticides

• Large fields of crops of the same type = monoculture 
• Monocultures attract a lot of pests, this reduces prodcutivity (food and finacial gain)
• To reduce the amount of pests, farmers use pesticides which are chemicals that kills the pest
• Advantages to pesticides is that it is easy to obtain, apply and are very effective
• Disadvantages to pesticides is that they are toxic and are harmful to humans and animals

5.3 Fertilisers

• Fertilizers take the form of nitrates and phosphates
• Fertilizers are taken up the root by active transport and dissolved in water which is taken to the leaf by the xylem
• Nitrates are involved with protein and Phosphates are involved with DNA and membrain strcuture 
• There are 2 types of fertilizers (artificial and organic)
• Artificial takes the form of Potassium Nitrate and Ammonium nitrate
• Organic takes the form of animal waste (most of the time cow waste)

5.2 Crop Yield

• Increasing in temperature will also increase the rate of reaction of enzymes of the plant 
• Increased concentration in CO2 is substrate
• Increasing the temperature and the carbon dioxide level will result in an increase in the rate of photosynthesis
• An increased rate in photosynthesis means that the plants will produce a higher yield 
• Formula for photosynthesis is carbon dioxide + water = oxygen + glucose

5.1 Glasshouses

• Glass houses are made of glass to let as much sunlight in as possible
• Solar radiation is the source of energy (from light)
• Light goes through the glass and is absorbed by the surface inside the glass house (soil, plants etc.)
• Plants re-emit the heat thus causing warm air and causing increase in temperature
• High temperature enables plants to increase yields to certain crops. 
• Such as constant temp. per year, prevention of frost damage and prevention of loss of water vapor

2.77b Thermoregulation

• Hyperthalamis is a region of the brain which responds to the stimuli (temperature of blood)
• Temperature is the stimuli, hyperthlamis is the receptor, skin activity is the responce
• If temperature is too warm, the response of the skin would be sweating, vasoliation and hairs flat
• If temperature is too cold, the response of the skin would be shivering, hair raised and vasoconstriction
• Homeothermic carries out a process called Thermoregulation.
• Mammals body temperature is 37 to 38 degrees celcius

http://www.youtube.com/watch?v=Eb6Fj2ftYfI&feature=related

2.76 Sensitivity

• Sensitivity is the characteristic of the organisms respond to changes in their environment. 
• Changes in the environment is also known as the stimuli which include: Light, temperature, pressure and chemical.
• Organisms are required to have receptors and effectors such as muscles and glands, to detect the stimuli
• Response is used to adapt to the stimuli to survive the changes in the environment.
• The "s" in mrs. gren stands for sensitivity
  http://www.youtube.com/watch?v=U9faLNDFSNY

2.75 Urine

• Urine contains water salts and urea.
• The removal of urea is a part of excretion and metabolic waste.
• Salts and urea is removed by osmoregulation to maintain isotonic tissue.
• The salt, water and urea composition in each person varies depending on the condition the person is in.

2.74 ADH

• ADH- Anti Diuretic Hormone.
• It flows through the blood stream to the kidneys.
• It is produced in the region of the brain known as the hypothalamus. 
• It controls the amount of water in the blood.
• Tissue fluid should be isotonic with the cells.

2.73 Glucose re-absorption

• A molecule is selected and is reabsorbed back into the blood.
• The molecule gets removed from the blood and is put back in.
• If there is glucose in urine, the person could have diabetes.
• There usually is no glucose in urine.
• In the first convoluted tubule glucose is removed and out back into the blood.

2.72 Water re-absorbtion

• When the ultrafiltration occurs in the Bowman's capsule, too much water is filtered.
• The water is removed from the filtrate.
• It is then added into the blood vessels.
• This is called selective reabsorption.
• As it passes through the Collecting Duct, water is removed from the filtrate. 

2.69 Urinary system

• There are two kidneys in the urinary system with separate blood supplies.
• Which uses process of excretion and filtration.
• Each kidney there is a tube which lead to the bladder called the urethra.
• The ureter carries urine from the kidney to the bladder.
• The urine is conducted to the outside of the body to be excreted which travels down the vagina or penis.

2.68b Osmoregulation

• The fluid which surround cells are isotonic with the cytoplasm of the cells.
• The amount of water going into these cells are equal and remain the same size and shape.
• The kidney controls the composition of our blood.
• Blood circulating in to the tissues it will be concentrated causing hyper tonic tisse fluid or hypo tonic tissue fluid.
• Blood that circulates through our kidney excess water, excess salt can be removed and excreted at the urethra.

2.68a Excretion

Urea contains nitrogen which is toxic to the body and cannot be stored.

Amino acids are normally use for growth but the extra amino acids is excess must be remove there toxic.

The blood circulated to the liver and the amino acids are converted around which is called urea.

The kidney will filter the urea from the blood. 

The urea is drained and collected in the bladder.

2.67b Human organs of Excretion

• Salt and water is from sweat.
• Lungs excrete carbon dioxide which is a waste from respiration.
• The kidneys are responsible for the excretion of excess water (Amino Acids)
• The 3 organs of excretions are the lungs, kidneys and skin.
• The skin would give out water, salt and urea. 

2.67a Excretion in plants

• The process of photosynthesis happens when Carbon dioxide and water which give off oxygen.
• Respiration is C6H12O6 +O2 which which gives off gas as a waste molecule.
• Photosynthesis is CO2 + H2O ----> C6H12O6 This happens due to the release of metabolic waste.
• Glucose molecule is broken down and energy is used to form ATP and get the waste of carbon dioxide and water given off.
• The waste process is called Excretion.

3.34 Causes of Mutation

3.33 Antibiotic Resistance

3.2 Types of Mutation

3.31 Evolution