2.69 Urinary system

• The urinary system we have 2 kidney the right one and the left one. Each with it's own separate blood supply.
• Carrying out the process of excretion and filtration osmoregulation.
• From each kidney there is a tube that lead to the bladder this is called the ureter.
• The ureter carry urine from the kidney to the bladder.
• The urine is conducted to the outside of the body to be excreted down the structure called urethra which either travels down the vagina or down through the penis.

*Why is the urine is outside not inside?

2.68b Osmoregulation

• The fluid which is surround these cells are isotonic.
• The amount of water going into these cells are equal and remain the same size.
• In the tissues it will be concentrated.
• It would be diluted and be Hypotonic.
• Through our kidney it would be water and salt.

* Why does it excreted salt and water if it's go through the kidnet already?

2.68a Excretion

• Excretion in kidney. The molecule of urea.
• 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 serculated to the liver and the amino acids are converted around whihc is called urea.
• The kidney will filter the urea from the blood.

*Why does the kidney need to be filter?

2.67b Human organs of Excretion

•  Lungs would be waste from respiration is carbon dioxide.
• The kidney is responsoble for the excretion of excess water, molecule urea which is nitrogen waste from amino acids and salt.
• The skin would give out water, salt and urea. 
• Salt and water is from sweat.
• 3 organs of excretions are lungs, kidney and skin.

*Why is it only lungs that givesut CO2?

2.67a Excretion in Plants

• The process of photosynthesis. Carbon dioxide and water which gives off the gas is oxygen.
• The release of metoballic waste.
• Respiration is C6H12O6 +O2 which enzym is needed to make this process work.
• This would form ATP.
• The waste process is called Excretion.

* What does the ATP stand for?

3.34 Causes of mutation

• The mutation is the change in the base sequence.
• There are 2 examples of what cause the changes.
• First example is radiation, x-rays which is UV-B rays would cause diseases which is skin cancers.
• Second is chemicals tars which cause cancers.
• Chemical which cause mutations are called mutagens which cause cancers and they would be called "carcinogen".

3.33 Antibiotic resistance

• Staphylococcus aureus is skin infection and lung infection.
• People could use methecilline (antibiotic). Susceptible is kill by methecilline which is MSSA.
• Random mutation is when the antibiotic apply but the bacteria did not die.
• We would use resistance which is MRSA.
• It would increase more bacteria survives and its would be common.

3.32 Types of mutation

• The process of mutation produce new alleles.
• The impact of the new alleles is benificial,harmful and neutral (no effect).
• Benificial e.g. is enzyme.
• Harmful e.g. is non-functional enzyme.
• Neutral e.g. is environmental change.

3.31 Evolution

• The evolution is the change of  the form of organisms and the change of frequency (how many) of alleles.
• Natural selection is the mechanism of evolution.
• There are 2 features. Random mutation which produces MRSA.
• Another feature is non-random selection due to the anti-biotic to surve MRSA and MSSA is select and kill.
• These two processes are natural selection process.

3.30 Mutations

• The form of the gene is called " Allele".
• The order of the chai is change bewteen the 2 diagram. So, it's different kind of proteins.
• Different effect on the phenotype.
• This process is called "Mutation".
• The changes in the base sequence of the chain.

3.29 Species Variation

• Variation is the differences that we could see in the phenotype and we could measure the differences.
• The individual phenotype is their genotype and environment. Variation of the population is there variation in genotype and variation in environment.
• The variation in population or species is the environmental variation.
• Example: home language.
• There are 3 scenarios.