-2 Kidneys (Each with its separate blood supply. Conducts excretion, filtration and osmoregulation)
-2 Ureters (Carries urine from the kidney to the bladder)
-1 Bladder
-Urine is carried down the urethra to the outside of the body
Monday, 31 October 2011
2.69 - Urinary system
Urinary system has:
-2 Kidneys (Each with its separate blood supply. Conducts excretion, filtration and osmoregulation)
-2 Ureters (Carries urine from the kidney to the bladder)
-1 Bladder
-Urine is carried down the urethra to the outside of the body
-2 Kidneys (Each with its separate blood supply. Conducts excretion, filtration and osmoregulation)
-2 Ureters (Carries urine from the kidney to the bladder)
-1 Bladder
-Urine is carried down the urethra to the outside of the body
2.68 - Excretion & Osmoregulation
EXCRETION
Kidneys excrete urea
-Urea contain nitrogen
-Nitrogen is toxic to the body and cannot be stored
-Amino acids contain nitrogen
-Amino acids are used for growth but excess amino acids must be removed because they are toxic.
-Removing the excess amino acids is the job of the liver and the kidneys
1) Blood circulates to the liver and the amino acids are broken down and are converted to urea
2) This reenters the blood stream and to be removed from the body it circulates to the kidneys
3) The kidneys filter the urea from the blood and water will be added to the urea and forms urine.
4) Urine drains down the uriters to collect in the bladder.
Urea is now in the bladder in the form of urine. (Removed from the body)
OSMOREGULATION
Osmo = Osmosis
Regulation = Control
-The tissue fluid which surround the cells must be isotonic with the cytoplasm of these cells (Amount of water in&out is =. The cells will remain the same size/shape and maintain their function)
-The danger to the tissue is that blood circulating into the tissue would be concentrated causing a hypertonic tissue fluid or it may be very dilute causing a hypotonic tissue fluid (Both of these are undesirable)
We want to keep the tissue fluid isotonic to the cell cytoplasm.
This is achieved by controlling the composition of blood. blood forms the tissue fluid.
It is the role of the kidney to control the composition of our blood.
Blood which circulates through our kidney
Excess water and salts can be removed and excreted through the ureter to control the composition of the blood and this means that the tissue fluid could be kept isotonic with the cells cytoplasm.
Kidneys excrete urea
-Urea contain nitrogen
-Nitrogen is toxic to the body and cannot be stored
-Amino acids contain nitrogen
-Amino acids are used for growth but excess amino acids must be removed because they are toxic.
-Removing the excess amino acids is the job of the liver and the kidneys
1) Blood circulates to the liver and the amino acids are broken down and are converted to urea
2) This reenters the blood stream and to be removed from the body it circulates to the kidneys
3) The kidneys filter the urea from the blood and water will be added to the urea and forms urine.
4) Urine drains down the uriters to collect in the bladder.
Urea is now in the bladder in the form of urine. (Removed from the body)
OSMOREGULATION
Osmo = Osmosis
Regulation = Control
-The tissue fluid which surround the cells must be isotonic with the cytoplasm of these cells (Amount of water in&out is =. The cells will remain the same size/shape and maintain their function)
-The danger to the tissue is that blood circulating into the tissue would be concentrated causing a hypertonic tissue fluid or it may be very dilute causing a hypotonic tissue fluid (Both of these are undesirable)
We want to keep the tissue fluid isotonic to the cell cytoplasm.
This is achieved by controlling the composition of blood. blood forms the tissue fluid.
It is the role of the kidney to control the composition of our blood.
Blood which circulates through our kidney
Excess water and salts can be removed and excreted through the ureter to control the composition of the blood and this means that the tissue fluid could be kept isotonic with the cells cytoplasm.
2.67 - Excretion
a) In plants:
1) Photosynthesis =absorbing light energy
CO2 + H2O --------> C6H12O6 + O2
O2 is the waste molecule, the release of metabolic waste is an example of excretion
2) Respiration
C6H12O6 + O2 ---------> ATP + CO2 +H2O
The CO2 is also metabolic waste so plants excrete:
-Oxygen
-Carbon Dioxide
b) In Humans (Human organs of Excretion)
1) Lungs - excretion of metabolic waste = Carbon dioxide
2) 2 kidneys - excretion of excess water, urea(nitrogen wastes from amino acids) and salt
3) Skin - mostly water and salts and a bit of urea
1) Photosynthesis =absorbing light energy
CO2 + H2O --------> C6H12O6 + O2
O2 is the waste molecule, the release of metabolic waste is an example of excretion
2) Respiration
C6H12O6 + O2 ---------> ATP + CO2 +H2O
The CO2 is also metabolic waste so plants excrete:
-Oxygen
-Carbon Dioxide
1) Lungs - excretion of metabolic waste = Carbon dioxide
2) 2 kidneys - excretion of excess water, urea(nitrogen wastes from amino acids) and salt
3) Skin - mostly water and salts and a bit of urea
Monday, 10 October 2011
3.34 - Causes of mutation
Mutation is a change in base sequence and is caused by two things:
1) Radiation
-Ionising radiation (gamma/X-rays)
-Sunshine (UV-B), which causes skin cancer
2)Chemicals - Mutagens
chemicals which cause mutation are called Mutagens
chemicals which cause mutation and cancer are called Carcinogens
eg: Tar in tobacco (also causes cancer)
1) Radiation
-Ionising radiation (gamma/X-rays)
-Sunshine (UV-B), which causes skin cancer
2)Chemicals - Mutagens
chemicals which cause mutation are called Mutagens
chemicals which cause mutation and cancer are called Carcinogens
eg: Tar in tobacco (also causes cancer)
3.33 - Antibiotic resistance
Staphylococcus Aureus can be treated with an anti-biotic called methacilline, this cures SA in its susceptible form (MSSA)
However, through random mutation there is a type of SA that doesnt die when given methecilline, this type of mutation is the resistant form of SA (MRSA)
However, through random mutation there is a type of SA that doesnt die when given methecilline, this type of mutation is the resistant form of SA (MRSA)
3.32 - Types of mutation
There can be 3 types of mutation:
-Harmful (Creates and enzyme that doesnt work - non-functional enzyme)
-Neutral (no apparent effect)
-Beneficial
Over time the neutrality can become either beneficial or harmful depending on the enviromental change
-Harmful (Creates and enzyme that doesnt work - non-functional enzyme)
-Neutral (no apparent effect)
-Beneficial
Over time the neutrality can become either beneficial or harmful depending on the enviromental change
3.31 - Evolution
Evolution:
-Change in the form of organisms
-Change in the frequency of alleles
Natural selection is a mechanism of evolution and was first proposed by Charles Darwin
-Change in the form of organisms
-Change in the frequency of alleles
Natural selection is a mechanism of evolution and was first proposed by Charles Darwin
3.30 - Mutation
-Certain processes/events result a change it the base sequance (ACT --> AAT)
-this change creates a new version of the allele
-This allele can produce an entirely different protein and a different effect on the phenotype (Big A, Little a)
-The reasons why different alleles exist is because of the process known as mutation
-Mutation changes the base sequence
-this change creates a new version of the allele
-This allele can produce an entirely different protein and a different effect on the phenotype (Big A, Little a)
-The reasons why different alleles exist is because of the process known as mutation
-Mutation changes the base sequence
3.29 - Species Variation
Variation = Differences in phenotypes (how things appear)
possible to count/measure these differences in graphic form
These variation of species depend on the species genotype and environment
possible to count/measure these differences in graphic form
These variation of species depend on the species genotype and environment
Monday, 3 October 2011
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