2.75 Urine

• Urine contains water, salts and urea.

2.74 ADH

• ADH stands for Anti-diuretic hormone.
• ADH is produced in the region of the brain known as the Hypothalamus.
• It flows through the blood stream and its target is the kidney.
• The effect of ADH is to control or alter the quantity or composition of water in blood.
• ADH has the ability to make the blood more or less concentrated.
• ADH targets the collecting duct.
• ADH is responsible for increasing the amount of water added to the blood.
• The urine becomes more concentrated and the volume decreases.

2.73 Glucose Reabsorption

• The glomerula filtrate contains glucose.
• Normally urine does not contain glucose unless this person has diabetes.
• In the proximal convoluted tubule glucose is removed.
• Glucose is then taken back into blood.
• Glucose is selectively reabsorbed into blood in the proximal convoluted tubule.
• 
  

2.72 Water re-absorption

• When the filtration occurs it will filter out too much water.
• As the filtrate passes through the structure to the collecting duct, water is removed from the filtrate.
• The water is then returned back into the blood vessels.
• The water will go back into the blood stream.
• The water has been selected and been reabsorbed into the blood.
• Then we get the phrase selected reabsorption.

2.71 Ultrafiltration

• Nephron is the structure which carries out the filtration of our blood.
• The filtration of blood begins with the arrival of blood in the afferent arteriole.
• The blood is under high pressure.
• The blood vessel starts to branch and become much smaller. This coiled structure is known as the glomerulus.
• The blood vessel coming out of the Bowman's capsule has a smaller diameter than the blood vessel going in.
• The blood pressure increases in the glomerulus.
• The high pressure forces the liquid within blood (plasma) out of the blood vessel.
• Plasma contains water, salts, amino acids, glucose and urea.
• The plasma is then referred to as the glomerula filtrate.

2.70 Nephron Structure

• The dead-end, cup shaped structure is known as the Bowman's capsule.
• The Nephron structure is made up of twisted structures known as the convoluted tubules.
• The tube that begins from the medulla to the cortex is known as the collecting duct.
• The dip down from the cortex to the medulla then back to the cortex is called the loop of Henle.
• The tight knot of blood vessels in the Bowman's capsule is known as the glomerulus.
• The first twisted section is known as the proximal convoluted tubules (PCT) and the second twisted section is known as the distal convoluted tubules (DCT).
• There are millions of these Nephrons in a single kidney.

2.69 Urinary system

• In the urinary system there is the right kidney and the left kidney
• Each with its own separate blood supply.
• Carrying out the process of excretion and filtration.
• From each kidney there is a tube that leads to the bladder,(ureter)
• The ureter carries urine from the kidney to the bladder.
• The urine is conducted to the outside of the body.
• To be excreted down the structure called the urethra.
• Then either travels down through the vagina or through the penis.

2.68b Osmoregulation

• Osmo refers to osmosis and regulation to control.
• Isotonic with the cytoplasm of the cells.
• This means that the amount of water going into
  and out of the cells is equal.
• The cells will remain the same size and shape
  and maintain their function.
• Danger to the tissue is that blood circulating into
  the tissue would be concentrated.
• This causes a Hypertonic tissue fluid or a(concentrated)
• Hypotonic tissue fluid. (dillute)

2.68a Excretion

• Urea contains nitrogen.
• Nitrogen is toxic to the body and cannot be stored.
• The original form of nitrogen are the amino acids.
• Blood circulates to the liver and the amino acids are
  broken down into the molecule known as urea.
• This then circulates to the kidneys.
• The kidneys will filter the urea from the blood.
• The urea will be added to water to form urine.
• This urine drains down the ureters.
• To then collect in the bladder.

2.67b Human organs of excretion

• Lung, kidneys and skin are organs of excretion
• The metabolic waste that the lungs excrete is carbon dioxide.
• Kidneys are responsible for the excretion of excess water, the molecule urea and salts.
• The skin is known to excrete water, salts and little urea.
• The skin excretes salts and water through sweat.
• The lung excretes carbon dioxide through the respiratory system.
• The kidney excretes water, salt and urea through urine.

2.67a Excretion in plants

• Considering the process of photosynthesis
• Involves leaf absorbing light energy.
• In the process of doing so it combines C02 with water
• This forms molecules such as glucose.
• Gives off the gas oxygen, this is a waste molecule so is an example of excretion
• Respiration, aerobic respiration to supply oxygen.
• Through a series of enzyme reactions the glucose is broken down.
• The waste carbon dioxide and water. 
• Plants excrete water and excrete carbon dioxide.

3.33 Antibiotic Resistance

3.32 Types of Mutation

3.31 Evolution

3.30 Mutation

3.29 Species Variation

3.22 Chromosomes and sex Dertemination

3.21b Genetic Probabilities

3.21 Predict probabilities of outcomes from monoybrid crosses.

• Both parents are heterozygotes
• The next process is Meiosis, the alleles need to be seperated
• 50% chance that they will be carrying the big R or little r allele
• RR:2Rr:rr , Red:Red:White
• 75%:25% or 3/4:1/4
• 
  

3.21a Genetic Probabilities

3.21 Predict probabilities of outcomes from monohybrid crosses

• Gamete will contain only one of the 2 alleles
• Then we consider random fertilisation
• Do this by drawing a table to illustrate the possibly fertilisations  that can occur between the pollen grains and the ovules
• In this example it would give us heterozygotes in all squares
• The Genotype of the offspring is big Rr.

3.20 b Pedigree2

3.20 Understand how to interpret pedigree diagrams.

3.20 Pedigree Diagrams (a)

3.20 Understand how to interpret Pedigree diagrams

• The shaded in diagrams usually represent an inherited condition a male or female has recieved
• Circles and squares represent phenotypes
• Vertical lines represent the bond from parent to child
• Horizontal lines represent partners bond
• An open circle or open square is referred to as"normal" whereas a shaded circle or square is referred to as "affected"

What does each line represent?

3.19 b F1 x F1 Cross

3.19 a P1 x P1 Cross

3.18 b Genotypes

3.18a Phenotypes

3.12 - Amniotic fluid

In the uterus space there is the amniotic fluid

functions: 

- can protect the developing embryo - comes from the fluid  (largely water) not being able to be compressed. 

- When you try to squeeze the fluid it absorbs the pressure. 

- This means any blows or force applied to the uterus wall - the amniotic fluid will absorb this pressure and will prevent damage to the unborn child. 

example of absorbing the pressure: 

in a swimming pool when you try to kick it with your leg - leg doesn't move very quickly, hard to generate great force. - example of how the fluid absorbs the force. 

3.11 - Placenta

when the child is in the uterus - water filled environment (amniotic fluids) - child cannot digest or breath or excrete

- baby obtains food - blood vessels lead from the embryo down the umbilical cord and then spread out to form placenta. 

- placenta biologically grows out of the developing embryo. not out of the mother. 

- blood vessels inside the placenta are the child's (veins and arteries) 

- placenta grows into the lining of the uterus (wall) 

- mother continues to eat and so in the blood vessel we have things like glucose, amino acids and fats. these travel through blood stream and into the wall of the uterus. they then cross into the childs blood at the placenta. 

- to make this efficient the placenta has a large surface area and the barrier between the mother and childs blood is very thin. 

- child produces CO2 and Urea which then goes back into the mothers blood. 

3.9b - Female Reproductive System

before a pregnancy occurs the uterus structure is no larger then an orange.

Ovary - meiosis occurs and production of female gamete(eggs) 

Oviducts - carry the eggs to the uterus and where fertilization takes place. where sperm cells meet the egg cells. 

Uterus - wall of the uterus is made of muscle. stretches to accommodate pregnancy and contracts during birth. 

Lining of the uterus - develops the fertilized egg into the embryo and then the child. can see the development here of the placenta 

Cervix - entrance to the uterus - where sperm cells enter. 

Uterus space - where the sperm and egg cells move. Embryo develops into the unborn child

Vagina - collects the sperm cells and allows them to pass throw the cervix into the uterus 

3.9a - Male Reproductive System

Bladder - Store urine 

Testis - 2 of them - carry out meiosis - produces the gamete, sperm 

epididymis - stored sperm cells 

vas deferens - carry sperm cells to the penis during sexual stimulation. the tube pulses making the walls contract and push the sperm from the testis to the penis

prostate - adds about 20/30% of the volume of the semen. contains sugars and is alkali. 

Seminal Vesicles - 70& of the volume of the semen. contains sugars and is alkali 

When sperm cells are combined with the prostate and seminal vesicles secretions we have semen. - carried forward and down to the urethra 

Urethra - common tube that joins the left and right testis. takes semen/urine down the penis

Penis - carries sperm cells into the vagina during sexual intercourse 

3.24a Mitosis

3.24 Understand that division of diploid cell by mitosis produces two cells which contain identical sets of chromosomes.

• Mitosis is a form of cell division which results in growth and the growth occurs by an increase in the number of cells.
• The number of chromosomes in the nucleus is known as the diploid - 2n. 2n = 46
• Each of the diploid cells has a nucleus. Often say that the cells are identical / daughter.
• They are identical because, they have the same number of chromosomes and because they have the same set of chromosome.

3.16 DNA and Genetic information

chromosomes= contain 1000's gene

gene loci--> double helix ( theres two, theres a pair to be parallel) --> sugar-phosphate backbone ( no chemical details required) is holding these two strands together

In the center theres a group of molecule called bases which there is 4 different type of base:

-adenine (A)

-thymine  (T)

-cytosine (C)

-guanine (G)

These bases are holding the two helixes they are held together by paring each other:

A=T

G=C

these are base pairs, these are always found in the DNA, they are glueing together from one side of the double helix with the other

(expand) =ACTGAACCAG : order of molecule this order is the GENE (inside the nucleus/order of bases/number of bases= construction of protein in the cytoplasm--> giving us the characteristic) 

Q: how to each molecule know which one to pair to?

http://bellebiology.blogspot.com/2011/08/316-dna-and-genetic-information.html

3.15 Genes

-- the gene carries information:

--characteristics of the organism

-- blood group

-- petal colour

- there will be a gene for each one of those

-the genes are located in the nucleus and the information is pass to the cytoplasm and in the cytoplasm the genetic information is transformed into the protein 

-which this protein controls the production of the characteristics

Q:Why and how do different people have different types of DNA/genes?

http://bellebiology.blogspot.com/2011/08/315-genes.html

3.14 Chromosomes

-chromosomes are the genetic information within a cell

-in each cell there will be a nucleus which contains a number of chromosomes 

- chromosomes are compose of a molecule called DNA (Deoxyribonucleic acid) which forms a shape known as the double helix

- and within the section is called genes

-1 chromosomes contains many genes about 1000 of genes

- each genes carry the information for the construction of a protein 

- the protein gives out the characteristic associated with the genes such as the blood group

- different organism has different number of chromosomes

Q: If chromosomes can't be reproduce, where do we get it from?
- does the chromosomes live inside you forever?
- or do they reproduce

http://bellebiology.blogspot.com/2011/08/314-chromosomes.html  

3.1 Sexual and Asexual reproduction

3.1 Describe the differences between Sexual and Asexual reproduction

• Organisms that show sexual reproduction show sexes (male/female). No sexes exist in Asexual reproduction.
• Sexual reproduction has Gameke cells in the sperm and egg cells. Asexual does not have Gameke cells.
• Meiosis is a cell division that produces Gamekes. One of Meiosis' effects is to half the number of chromosomes in the Gameke cell. 
•  Total number of chromosomes in a human is 46 per cell. In Gamekes the total number is 23 per Gameke cell. From 46 to 23 is the process of Meiosis.
• In Asexual reproduction there is Mitosis and Binary fission bacterial cells. Number of chromosomes is maintained constantly.
• In Sexual reproduction there is the process of fertilisation, where the sperm cell and egg cell fuse together. In Asexual reproduction there is no fertilisation and no fusion of cells.
• Many differences in the individuals of a sexual reproducing population. Where as Asexual show a small amount of variation, mainly identical (clone).  

What is the process of Meiosis?

4.14 Enhanced Greenhouse Effect

4.14 Understand how an increase in greenhouse gases results in an enhanced greenhouse effect and that this may lead to global warming and its consequences.

• As the green house gases increases it means that more infra-red light will be trapped therefore more global heating 
• Consequences: 
• Polar ice caps melt causing increase in sea level and change in global water currents 
• Average global temperature effects the habitat of animals, biomes will change and move 
• Ice caps will disappear, deserts will grow. forest will dry up 

4.13 Greenhouse gases

4.13 Understand how human activities contribute to greenhouse gases.

• Human activities cause an increase in green house gases 
• This is because we burn fossil fuels and this causes more green house gases to be released 
• Things such as: Cars, Factories, Homes, Farming (paddy fields and cow farts produce Methane), refrigerating and aerosol cans (produce CFC's)

4.12 Greenhouse Effect

4.12 Recall that water vapour, carbon dioxide, nitrous oxide, methane and CFCs are greenhouse gases.

• Uv light is short wavelength with high energy
• When it comes into the atmosphere it gets reflected of the earth's surface back into space as infra-red light 
• Green house gases such as water vapour, methane, carbon dioxide etc trap the infra-red rays 
• Once the heat is trapped the overall global temperature increases 

4.11 Gas pollution

4.11 Understand the biological consequences of pollution of air by sulphur dioxide and by carbon monoxide.






Carbon Monoxide:

• Caused by burning of fossil fuels and coal with insufficient oxygen 
• Is very to toxic to living things especially humans 
• Bonds with the Hemoglobin in the red blood stream and causes oxygen depletion in the blood stream

When fuels are burnt toxic gases are produced
Sulphur dioxide:

• Is caused by the burning of coal and oil from factories 
• Sulphuric acid forms acid rain (changes the ph of the water)
• Causes plants leaves to burn and roots to be leached of minerals resulting in no growth 
• Causes lakes to become acidic and reduces oxygen levels suffocating fish

4.7 Energy Efficieny

4.7 Explain why only about 10% of energy is transferred from one trophic level to the next.

• Only 10% of Energy moves on from one animal to the next 
• The secondary consumer only gets 1% of the original energy 
• Consumers do not get 100% of the energy because energy is used up in respiration and excretion

4.6 Energy and Substances in Food chains

4.6 Understand the transfer of substances and of energy along a food chain.

• Producers change the energy from the sun into chemical stored energy that they can use for respiration 
• Chemical energy are lipids, carbohydrates and proteins 
• The producer breaks the bonds in the molecules which contain energy 
• When something eats the producer the enrgy is passed on 

4.5b Food webs

4.5b Understand the concepts of food chains, food webs, pyramids of number, pyramids of biomass and pyramids of energy transfer.



• Shows ecosystem
• Shows interaction (feeding) of a community of organism
• Organisms have multiple predators/multiple prey• Feeding at different tropic levels 
• It is a link of many different food chains 

4.5a Food Chains

4.5 Understand the concepts of food chains, food webs, pyramids of number, pyramids of biomass and pyramids of energy transfer.

• The food chain links together the producer to the primary consumer then to the secondary consumer and possibly to the tertiary consumer.
• 1 organism per trophic level.
• In a food chain unable to show an organism to be an omnivore or to be feeding at more than 2 trophic levels.
• Food chains build a flow of matter and they show the flow of energy.

4.4 Trophic Levels

4.4 Recall the names given to different trophic levels to include producers, primary, secondary and tertiary consumers and decomposers.

• The word trophic means to feed
• There are different feeding levels
• Carrot plant is the first level in the example and is doing photosynthesis
• Carrot fly is eating parts of carrot plant and is therefore called a herbivore
• The flycatcher eats the carrot fly which makes it a carnivore 
• Carnivore eats another carnivore (top of the food chain) Top Carnivore
• Carrot plant is called the producer
• Carrot fly eating carrot plant is known as the primary consumer
• Flycatcher is then known as the secondary consumer
• After that the next feeding level is called tertiary consumer

4.3 Quadrat samples

• A sample that is random form each comparison is needed
• A sample that is a representative for each comparison
• Random numbers are needed to be generated
• Random numbers are used for the x and y coordinate
• Count number of samples in each square

4.2 Quadrats

4.2 Recall the use of Quadrats to estimate the population size of an organism of 2 different areas.

• Quadrats are based on squares.
• Squares can be made of any material including wood, string and metal.
• Quadrat is used to sample the area and count the
  number of individuals inside the grid.
• This is an estimate of the population size.
• Quadrats are a method of sampling so that populations can be compared
  in the different locations.

4.1 Ecosystems

4.1 Understand the terms: population, community, habitat and ecosystems.

• Ecosystems are described by the community of organisms and the habitat.
• The habitat includes all the Abiotic factors (non biologic factors) for example, cycle of daylight
• Community of organisms is made up of populations of different species which are interacting
• Common interaction to look at is feeding

3.4 Plant Fertilisation

• The pollen tubes will only complete if they are from the same species. 
• The nucleus travels down the pollen tube and into the ovule. 
• Pollen nucleus will fertilize the ovule and will leave to a formation of a zygote and will grow into the embryonic plant. 
• The outside of the ovule forms the seed coat also know as the TESTA. 
• Cotyledons are the food stores for the seedling and will support the plant until it develops its first set of leaves. 

3.3a Insect Pollination

• A pollination flower transfers pollen grain from the anther to a stigma of a plant. 
• A pollen is a small structure that contains male nuclei. 
• Transfer in an insects pollinated plant is taken place by insects. 
• Its necessary for this plant to attract insects. 
• If pollen goes from one plant to another this is called cross pollination.

3.3b Wind Pollination

• Transfer of the pollen grains are from the anther. 
• The pollen grain from the anther to the stigma is through air carried by the wind. 
• Pollen grain has lightweight pollen grains, which some wing feature. 
• It would probably let it move for efficiently through the air. 
• There is no color in the petals and no smell to attract insects.