• Before: Replication of subcellular structures
• DNA replicates forming two copies of each chromosome, also grows and copies its internal structure such as mitochondria and ribosome 
• Mitosis takes place, one set of chromosome is pulled to each end of the cell. The nucleus also divides
• In the final stage, the cytoplasm and cell membrane divide to form two identical cells

• Essential for growth and development of multicellular organisms 
• Mitosis takes place when an organism repairs itself
• Happens during asexual reproduction

Place one drop of iodine solution into each well of a spotting tile

Take 3 test tubes: 2cm³ of starch solution, 2cm³ of amylase solution, 2cm³ pH 5 

Place all test tubes into a water bath at 30*C, leave for 10 minutes to reach the correct temperature

Combine the three test tubes into one test tube, mix with stirring rod.

After 30 seconds use the stirring rod to transfer one drop to the well with iodine. Should turn blue-black from orange - starch is present

Continue every 30 seconds until the iodine remains orange - starch is no longer present, repeat for different Ph Buffers 6,7 and 8

• Only taking sample every 30 seconds, approximate time for the reaction to complete, could do 10 seconds instead
• When the iodine goes blue-black it is not always obvious as the colour change is gradual. Use several people to look at the spotting tile and decide whether it is complete. 

Huge Surface Area 

Very Thin Walls - so diffusion path is very short 

Alveoli have very good blood supply, once oxygen diffuses into the blood, it is rapidly removed therefore steep concentration gradient

By breathing, we increase the rate of diffusion 

Breathing brings fresh oxygen into the alveoli and takes away carbon dioxide

Concentration gradient is very high for these gases. That increase the rate of diffusion

Genes regulate mitosis, however changes take place in these genes that leads to uncontrolled growth and mitosis

This produces a tumour

Benign tumour are the growths of abnormal cells which are found in one area

Contained within a membrane

Do not invade other parts of the body

Malignant cells invade neighbouring tissue through the blood stream

Malignant cells spread to other parts of the body - it makes new tumours(secondary tumours)

• Smoking: lung cancer
• Ultraviolet light: Skin Cancer
• Alcohol: mouth and throat cancer

• Types of breast cancer
• Prostate Cancer
• Cancer of the large intestine

For each food test, what chemical is required?

What are the Positive and Negative Result? 

Starch : Iodine Solution, P:Blue,N:Orange

Glucose: Benedict, P : Green/Yellow/Red N:Blue

Protein: Beirut Solution, P:Purple,N:Blue

SIBO

Great Balloons, Greet Yesterdays Ribs, Bluntly

PBPB

LED light bulb - as it does not release too much heat,

Too much heat would change the temperature of the experiment. 

What solution is used during the test for the rate of photosynthesis?

What Type of plant is used, and how is it positioned?

Sodium Hydrogen Carbonate Solution, as it releases carbon dioxide which is needed for photosynthesis

Pondweed is used with the cut end at the top, which has to been left for 5 minutes to acclimatise to the conditions of the boiling tube.

Should see bubbles of gas from the cut end of the pondweed, this gas is oxygen which has been produced due to photosynthesis

What are two problems with the rate of photosynthesis experiment?

How can these be fixed?

1. The numbers of bubbles can be too fast to count
2. A large bubble would count the same as a small bubble

To fix, place a pondweed under a funnel and catch the bubbles in a measuring cylinder, then measure the the volume of oxygen gas produced

Light Intensity ∝ 1/ distance²

Inverse Square Law: Doubling the distance, the light intensity falls by four times, because light is a reactant in photosynthesis this causes the number of oxygen bubbles to fall by four times

To Find the Base Value times Light intensity by distance², then use this base value and divide it by the distance² of another equation, to find the light intensity in that equation

• Start a stopwatch and count the number of bubbles produced after 1 minute at 10cm
• Repeat the experiment two more times and calculate the mean number of bubbles produced in one minute
• Do the whole experiment again from 20cm,then 30cm,then 40cm

• Red blood cells
• White blood cells
• Platelets - Fragments of Cells
• Plasma - Liquid Part of the Blood

What is the function of plasma?

What are the three main substances?

Transfers dissolved substances around the body

1. Soluble Digestion Products(Glucose) from the small intestine to other organs
2. Carbon Dioxide(aerobic respiration) from the organs to the lungs to be breathed out 
3. Urea(Waste Product) from the liver to the kidneys to be excreted in urine

What is function of red blood cells?

How are they adapted for this function?

Red blood cells transport oxygen from the lungs to the body cells.

Contain the oxygen-carrying molecule haemoglobin

• In the Lungs: Oxygen + Haemoglobin -> oxyhaemoglobin
• In Other Organs: oxyhaemoglobin -> Oxygen + Haemoglobin 

Red blood cells have no nucleus, which means they have more room to carry Haemoglobin. 

Biconcave Disk shape so greater surface area, so that oxygen diffuses in and out rapidly

Help the blood to clot 

1. To replace blood lost during injury
2. Given Platelets extracted from blood to help with clotting
3. Protein extract from blood can be used to make antibodies

• Mouth: Contains amylase in saliva
• Stomach: Contains Protease
• Duodenum(Top of the Small Intestine) - Continues digestion of carbohydrate and protein; as well as start digestion of lipids
• Ileum(Small intestine) - Complete digestion of carbohydrate and protein into single sugars and amino acids; absorption of single sugars, amino acids, fatty acids and glycerol
• Large intestine - Absorption of water; egestion(excreting unused material) of undigested food

• Contains Hydrochloric Acid which helps Enzymes digest proteins
• Churning action of the stomach muscles: turns food into fluids, therefore increasing the surface area for enzymes to digest. 
• glandular tissue - secretes enzymes which work well at low pH 

• Releases Bile - which speed up the digestion of lipids, as it emulsifies the fat giving them a bigger surface area
• Bile also neutralises the acid released from the stomach(2pH) to provide better conditions for Enzymes in the small intestine

 Branch out from the aorta and spread out into the heart muscle, provide oxygen to the muscle cells of the heart,

This oxygen is then used in respiration to provide the energy for contraction

Round in the right atrium of the heart

The natural resting heart is controlled by the pacemaker

Layers of fatty material are built up inside the coronary artery, causing the coronary arteries to narrow, therefore less blood flows

This causes a lack of oxygen in the muscle, and can result in a heart attack(where the heart is starved of oxygen)

Statins are drugs which reduce the level of cholesterol in blood, therefore slows down the rate that fatty acids build up in the arteries. 

Advantage: Reduce the risk of coronary heart disease

Disadvantages: Can cause liver problems 

A stent is a tube which can be inserted into the coronary artery to keep it open

Advantage: By inserting a stent blood can flow through normally through that artery(however doesn't prevent other regions of the coronary artery from narrowing)

Disadvantages: Could cause Blood clots, which close the artery and could cause heart attacks, and could also cause infection.  

1. Do not fully open - Heart has to pump extra hard to get blood through, can cause the heart to enlarge
2. Valves are leaky - Which can cause the person to feel tired and weak

• Can replace with a mechanical valve - made of metal
• Valve from an animal - such as a pig.

Mechanical valves can last a lifetime, however they increase the risk of blood clots.

Patients have to take anticlotting drugs.

Do not last long, and may need to be replaced

However, patients do not need to take drugs

• Not enough donated hearts to treat every patient
• Patient must take drugs to prevent the donated heart being rejected by the body's immune system.

• Increase the risk of blood clotting
• Can only be used for a short period of time

What are Vaccinations 

What are their advantages/disadvantages?

- Contain small amount of dead or inactive pathogens with specific antigen

- allows immune system to develop antibodies

-so any further infections can be dealt with quicker

Advantages:

- Small pox wiped out(get's rid of diseases) 

- herd immunity

Disadvantages:

- Don't always works

- painful/side effects

• Villi and microvilli increase surface area
• Long length increase surface area
• Rich blood supplies help carry absorbed molecules away to maintain steep diffusion gradient
• Thin walls means short diffusion distance
• Muscular Walls to squeeze undigested food towards the long intestine

• Toxicity - How many drugs can be taken before side effects are too bad
• Efficacy - How effectively it works compared to what is out there already in the market
• Dose - How much do you need to take to be effective

What is Penicillin?

When was it Discovered, who by and how?

What is Aspirin? 

How was it discovered?

What is Digitalis?

How was it discovered and what is is used for?

Aphids suck all the water/ions from plants.

Eaten by Ladybugs and Ants

glucose + oxygen -> water + carbon dioxide 

C₆H₁₂O₆ -> 6H₂O + 6CO₂

Exothermic reaction - energy given out

What is the formula for the anaerobic respiration in yeast?

(fermentation)

1. Bacteria
2. Viruses
3. Protists
4. Fungi

• DNA replicates it self forming two copies of every DNA
• Chromatin(nucleus) condense and coils, forming chromosomes, were both of the same type(original and clone) are connected
• These help evenly divide genetic material between daughter cells

• Takes up to 20 minutes(longest stage)
• Chromosomes line up in a straight line in the middle of the cell

• half of each number of X Chromosomes are pulled so hard to either end of the cell

• Chromosomes return back to Chromatin 
• Each of the cell's structures are reconstructed - such as cell membrane
• Then both cells break apart through Cytokinesis(cell movement)  
• This forms two genetically identical cells(daughter cells) from one cell

Contain 23 chromosomes(for humans)

Half of Normal chromosomes 

• Allows sexual reproduction of organisms
• Enables genetic diversity - DNA mixes between both parental chromosomes
• Allows the repair of genetic diversity - as recombination can replace bad allele with good ones

Vena Cava -> Right Atrium -> Right Ventricle -> Pulmonary Artery

^ 

Lungs(Through Capillaries)

Pulmonary Veins -> Left Atrium -> Left Ventricle - Aorta  -> Body Tissue

Repeat

Starch(type of Glucose) -  Storying energy

Glucose - Use for storage(cellulose) in plants and stored in humans glycogen(short-term) 

Lipids - Long term energy storage and to make a cell membrane

Protein - Makes muscle glands 

• They have permeable walls - allowing the passing of substances
• Very thin walls - short diffusion path

-Baby: Sperm Cell + Egg Cell forms zygote, carries out mitosis to form an embryo(which can differentiate into any type of cell) which differentiate into vital cells needed to grow into a baby. 

-Adult: Stem cells can only differentiate into an assigned type of cells, bone marrow can only differentiate into types of blood which helps with repairs

• Meristems differentiate into all types of cells, such as palisade and phloem, persist for the entire life, while embryonic stem cells in human disappear by the time humans are fully developed. 

Heterotrophs are organism that eats plants or other animals for energy and nutrients

Autotrophs can produce its own food through light energy, carbon dioxide or other chemicals

Saprophytes are plants, fungus or microorganism that lives on dead or decaying matter

• Giga - G - 10⁹
• Mega - M - 10⁶
• Kilo - K - 10³
• Centi - c - 10^-2
• Milli - m - 10^-3
• Micro - µ - 10^-6
• Nano - n - 10^-9

• When two numbers are placed in standard form, it is the difference between the order of which ten is multiplied by 

• Protective layer formed over the stomach
• Facillate movement of food masses 

Deoxygenated blood pumped from the heart to the lungs, and this oxygenated blood returns to the heart and is pumped around the body and the oxygen is given to the cells

Heart is known as a double pump, because each half pumps blood to a different circulatory system, right side to lungs, left to the rest of the body

• Large amount of ribosomes - enzyme is made from proteins
• Large amount of mitochondria - must get energy through respiration to release 

• It develops/acquires different sub-cellular structures/a particular shape/makes the protein it needs
• It Becomes specialised
• It enables it to carry out it's certain function 

What causes salmonella and what are the four side effects?

How can it be treated?

Caught by Chickens(not cooked properly) and spread when eaten(vaccine)

1. Fever
2. Stomach Cramps
3. Vomiting
4. Diarrhoea 

Treated by hydration passes over a week

STD (Passed on through sexual contact or inheritance)

• Pain when urinating
• Thick yellow discharge from the vagina or penis

-Embryonic stem cells have limited supply 

-Embryonic Stem cells may be rejected by the body

-This can be reduced by taking medicine to suppress the

immune system(though this does not always works)

-Adult Stem Cells can be taken from a patient(unlimited supply) 

-Adult Stem Cells won't be rejected by the body

-However Adult Stem Cells can only differentiate into different types of blood cells, therefore can only treat illnesses such as Sickle Cell Anaemia, while Embryonic can treat Diabetes and Paralysis 

• Virus Transmission - Donor stem cells infected with virus that when transferred they would spread the virus and cause more problems
• Tumour Development - because stem cells can divide so quickly they may get out of control and form tumours and cancer

1. Preclinical Drug Tests - tested through a computer model and human cells grown in a laboratory 
2. Animal trials - giving an animal a known amount of the substance and monitor the side effects
3. Human clinical trials - tested on healthy volunteers. Then on people with the illness to ensure it is safe and works. Low doses are used initially, and if safe the dose increases until optimum dose is identified  

What are the limiting factors in photosynthesis

How can these be fixed?

• Light intensity - use greenhouse constructed from glass or alternative material that enables maximum transmission of light. Artificial light can be used with optimum wave length of light for photosynthesis
• Carbon dioxide concentration - Paraffin heaters(small scale), use carbon dioxide waste from industrial processes(large scale). Liquid Carbon Dioxide through pipes. Fungi(Mycelium) that add carbon dioxide through respiration 
• Temperature - photosynthesis cannot take place at cold temperatures or if it is too hot(Enzymes denature)
• Chlorophyll - more able to absorb light as red and blue light is absorbed 

• Irrigation system is installed to increase yields. Plants may be sprayed with water to keep humidity(water vapour in the atmosphere) high
• Plants may be grown in liquid system called hydroponics, which allow the grower to optimise mineral ions given to plants. Mineral ions are required to synthesise other essential molecules from the glucose produced during photosynthesis.

What is the compensation point?

• Compensation point is lower in shade adapted plants than in plants with sunny conditions
• Shade adapted plants have more chlorophyll to absorb the light energy they need

• Red and blue light is absorbed by chlorophyll

• Chromosomal DNA - found loose in the cytoplasm 
• Plasmids - Small closed-circles of DNA in the cytoplasm. (unlike Chromosomal), plasmid DNA can more from one Bacterium to another via variation 
• Flagella(singular: flagellum)  - Can have one or more flagella. These can move or move in a whip like motion to move the Bacterium
• Cell Wall - provides structure and protection. However, only plant cell walls are made from cellulose

• Both have cytoplasm and ribosomes. However, bacteria does not contain mitochondria or chloroplast
• Prokaryotic divides by Binary Fission, while Eukaryotic divides by Mitosis.
• Eukaryotic are about 5μm - 100μm, while Prokaryotic are about 0.2μm-2μm
• Eukaryotic(Plant) cell walls are made of out cellulose, while Bacteria also has a cell wall but is not made from cellulose

• Acrosome contains Enzymes so that the sperm can penetrate the egg
• Middle piece is packed with mitochondria to release energy needed to swim and fertilise the egg
• Tail enables the sperm to swim 
• Haploid nucleus contains genetic information for fertilisation 

-Smoking damages the lining of the arteries, including the coronary arteries. This causes the build up of fatty materials in arteries. Can lead to heart attack and stroke

-Inhalation of carbon monoxide in cigarette smoke reduces the amount of oxygen that can be carried by the blood

-The nicotine in cigarette smoke increases heart rate, putting more stress on the heart

-Chemicals in cigarette smoke increase the likelihood of blood clotting, resulting in heart attack or stroke. 

A person may develop COPD(chronic obstructive pulmonary disease)

-Smoking damages the bronchioles and can eventually destroy many of the alveoli in the lungs

-Airway becomes inflamed and mucus, which normally traps particles in the lungs, build up

-The Patient becomes breathless, and find it hard to obtain oxygen needed for respiration 

• Smoking increases the risk of miscarriage
• Baby more likely to suffer from respiratory infections and an increased risk of asthma
• Long-term physical growth and intellectual development of the child is affected. 
• Risk of Birth Defects
• Birthweight of the baby is reduced

• alcohol causes lipids to build up in the liver - fatty liver disease
• alcohol damage leads to alcoholic hepatitis(inflammation or swelling of the liver), which can cause death
• Cirrhosis(scarring) of the liver can develop - looses its ability to function

Changes are irreversible and reduce the ability to process alcohol 

• Slows reaction time
• Causes difficulty walking
• Can impair memory
• causes slurred speech
• Changes in sleeping patterns and mood, including increased anxiety and depression

Fetus is:

• smaller in size
• smaller brains with fewer neurones
• long-term learning and behavioural difficulties
• Distinct facial features

• Leads to high blood pressure and build up of fatty deposits in the arteries, meaning less blood can flow(damages arteries).
• Also increases the likelihood of developing diabetes, high blood sugar can damage blood vessels 
• Increases blood pressure and increase levels of blood lipids

How one factor effects another

(e.g there is a casual link between smoking and lung cancer)

Contain filaments of protein that slide over each other to cause muscle contraction

Well-Developed mitochondria to provide the energy for muscle contraction

In skeletal muscle, the cells merge so that the muscle fibres contract in unison

• Dissolved sugars and amino acid can be transported both up and down the stem
• Sieves tube provide energy required to transport substances in the phloem

• Continuous column of water running through them(no top and bottom walls) 
• Walls become thickened and woody
• Support the plant