1. The Respiratory System: The Circulatory System:
Human Kidney
Vital for homeostasis
Everything filtered from blood and then reabsorption of all the glucose, as well as the mineral ions and water needed.
Active transport ensures ALL glucose is reabsorbed and diffusion makes sure mineral ions and water is reabsorbed in the right amounts
Hot day with little water intake = little urine (concentrated)
Diffusion
Osmosis
Active Transport
Movement of...
Liquid/gas particles
Water
Solutes (minerals/ions)
Concentration gradient
High → Low
Low → High
Energy? No
Yes
Membrane?
Not essential
Partially permeable
Yes, with carrier protein
Animal example
O2 across alveolus
Water in/out of cell
Villi & absorption
Plant example
Gas stomata
Guard cells, root hair cell
Root hair cell
The Blood
WHITE BLOOD CELLS
PLATELETS- help blood to clot
PLASMA- holds dissolved
substances, CO2, waste products (e.g. urea from the kidneys)
RED BLOOD CELLS- No
nucleus- more room for
Haemoglobin. Large surface area to absorb O2
HAEMOGLOBIN- substance
which gains oxygen from the
lungs to form OXYhaemoglobin.
Then releases oxygen into cells.
Dialysis
Transplant
Much more readily available
Enables you to lead relatively normal life
No risk of rejection
No need for medicine
Eat what you like
Lead a normal life
Free from restrictions which come with regular dialysis sessions
Rejection & availability?
The Intestine
VILLI= tiny protrusions in the intestine which help to absorb the products of digestion
Use active transport + diffusion to gain as much of the valuable materials, especially sugar, as possible
Adaptations of villi (AND ALVEOLI):
- Have a large surface area (squashed up)
- Are very close to a large network of capillaries (absorbed straight into blood stream)
- Thin wall
B3) Biology
The Respiratory System:
-O2 diffuses into your bloodstream and CO2 diffuses out.
-Alveoli=large surface area, efficient blood supply, thin walls.
- Inhalation = diaphragm contracts, ribs move up and out, more space in chest cavity, reduced air pressure, air drawn into lungs
Keywords: Active Transport, Osmosis, Diffusion, lungs, alveoli, villi, stomata, root hair cell
Sports Drinks:
Contain water, ions, and glucose
Replace glucose used in respiration
Replace water and ions lost in sweating
The Circulatory System:
Circulatory system = blood vessels, heart and blood.
Humans have a double circulatory system. Heart = pump.
3 main types of blood vessel:
Arteries (Away from heart), veINs (INto heart) and capillaries.
Valves ensure correct direction of blood flow
Arteries have thick muscular & elastic walls (narrow lumen/interior).
Artificial ‘stents’ can help keep arteries from narrowing
body’s
cells
lungs
Need:
Multicellular organisms and transport systems
Keywords: Transpiration, artery, vein, capillary, heart, red blood cells, haemoglobin, plasma, platelets, an/aerobic respiration,

2. Anaerobic Respiration
Thermoregulation:
If hot: sweating (heat lost when evaporates), hairs flat, vasodilation (increase blood flow to skin, heat lost through radiation).
If cold: shivering, vasoconstriction
Transpiration is the loss of water by evaporation from plants.
Plants lose water when they open the stomata in the leaves to let in carbon dioxide (controlled by guard cells).
Transpiration happens faster in hot, dry, windy conditions.
Exchange in Plants
Need osmosis in roots (for water) and diffusion near stomata (for CO2)
Leaves thin + flat to increase SA for light and a waxy cuticle to prevent evaporation
Root hair cells increase SA because of long, thin hairs
Most minerals + ions needed taken through roots
Fermenters
Microbes can be grown on a large scale using fermenters
Fermenters have features such as an oxgen supply, stirrer to keep microorganisms in suspension and maintain an even temp, water-cooler jacket to remove excess heat and measuring instruments such as pH and temperature gauges
Mycoprotein is produced by allowing the fungus ‘Fusarium’ to grow on sugar syrup in aerobic conditions
Wilting - when more water is lost than can be replaced
Type I diabetes: Not enough insulin produced, insulin injected
Type II: body not responsive to insulin. Diet carefully controlled.
Biogas – mainly methane – produced by anaerobic fermentation of a wide range of plants and waste materials that contain carbohydrates
Gets rid of waste, solves energy needs and is renewable, however hard to do it on a large scale
Xylem – transports water & ions, roots to leaves & stem
Phloem – transports sugars, bi-directional
Blood sugar regulation:
If high: pancreas releases insulin, glucose → glycogen in liver.
If low: pancreas releases glucagon, glycogen → glucose
Food production:
Energy lost at each stage in a food chain (due to respiration, movement waste materials etc.).
Improving efficiency in food production: decrease no. of stages, limit movement, control temp.
Keywords: Biogas, biofuels, mycoprotein, insulin, glucagon, glucose, glycogen, vasodilation
Anaerobic Respiration
Your everyday muscle movements are made possible by AEROBIC respiration
If heart rate is increased, blood cannot supply O2 quick enough
Anaerobic respiration = incomplete breakdown of glucose, releasing less energy
Glucose  Lactic Acid (+ energy)
Lactic acid needs to be got rid of (by reacting with O2 to form CO2 + water) = OXYGEN DEBT
Biofuels
Ethanol based fuels can be produced from anaerobic fermentation of sugar cane juices by the enzyme carbohydrase.
+Adv. = does’nt produce toxic gases, much cleaner and can be mixed with petrol, carbon neutral
Disadv. = needs lots of space, poor countries grow cash crops instead of feeding people  starvation.
Pollution:
Greenhouse gases: methane, CO2
Water pollutants: fertilisers, sewage, pesticides
Acid rain: sulphur dioxide, nitrogen oxides (cars, power stations)
Human impacts: deforestation (loss of biodiversity), removal of peat lands, building
Keywords: kidney, dialysis, transplant, immunosuppressant drugs, microbes, fermentation, alcohol, bacteria, lactic acid

3. Calculate the amount of water filtered each day [1mark]
1. The table below shows the amounts of some substances that are processed by the kidneys each day.
Calculate the amount of water filtered each day [1mark]
Calculate the % of sodium reabsorbed [1mark]
2. Plant roots absorb some of their mineral salts from the soil by active transport. What is involved in active transport? [4marks]
3. a) Describe the function of the pigment found in red blood cells [2marks]
b) Explain how red blood cells are adapted to perform their function [3marks]
Substanc e
Amount filtered
Amount reabsorbed
Percentage reabsorbed
Amount excreted
water
178.5 litres
99.2 %
1.5 litres
urea
56 g
28 g
50 %
sodium
units
units
150 units
5. Why is glucose found in the blood but not in the urine? Explain as fully as you can [3marks]
4. Kidney transplants can be treated or dialysis using a kidney ‘machine’. Discuss the advantages and disadvantages of using dialysis or kidney transplants to keep people alive [5marks]
6. A fresh fruit salad is made by cutting up fruits and placing them in a bowl with layers of sugar in between. After 2hrs the fruit is surrounded by syrup (concentrated sugar solution).
Explain why the syrup was produced after 2hrs [4marks]
8. The table below shows the composition of blood entering and leaving the lungs.
Describe in detail the changes that take place as blood passes through the lungs [3marks]
7. Oxygen is absorbed through the alveoli of the lungs. How are the alveoli adapted to perform this function? [3marks]
Gas
Concentration in arbitrary units
Blood entering lungs
Blood leaving lungs O2 40
100
CO2 46

4. Total marks: 65 Side A: 29 Side B: 36
1. The table below shows the economic costs and benefits of using a particular type of biogas generator. Using the table, discuss the adv. and disadv. Of using this type of generator [4marks]
2. During exercise the process of respiration produces excess heat. Explain how the body prevents this heat from causing a rise in core body temp. [4marks]
3. Describe the process of transpiration in plants [3marks]
Feature
Cost or profit (£)
Cost of generator and fitting
250
Annual maintenance costs 40
Annual profit from gas produced 30
Annual profit from fertiliser produced
6. Use the table below to explain how a cactus is better adapted to living in hot, dry conditions [4marks]
Feature
Geranium
Cactus
Thickness of waxy cuticle 5 15
Total leaf surface area (cm2)
1800
150
% of water storage tissue in stem 50 85
No. of stomata per mm2 59 13
Time of day when stomata open
daylight
night
Horizontal spread of roots (m)
0.2
5. Describe, in as much detail as you can, how the body responds to an increase in blood sugar concentration [3marks]
4. For this question write your answer on a separate sheet. The information in the table compares two farms.
a) Use this information to work out the average daily human energy requirement in kilojoules (kJ) per day [2marks]
Name
Grows…
Energy value of food for humans made in 1 year
No. of people whose energy needs are met by this food
Farm A
Food for humans
3285 million kJ
720
Farm B
Food for animals which are food for us
365 million kJ 80
7. Explain, as fully as you can, how agricultural activities are contributing to global warming [5marks]
Total marks: 65
Side A: 29
Side B: 36
8. Explain why after exercise, despite sitting down to rest, breathing rate and oxygen consumption remain high [4]
b) Explain why Farm A is much more efficient at meeting human food energy requirements [3marks]
c) The human population has been increasing rapidly throughout this century. It is now about 6 billion and is still growing. What does the information in this question suggest about likely changes in the human diet which may need to occur during the coming century? Explain your answer [4marks]

5. Side 1 Mark Scheme .
180 OR 179.9
99.4
Molecules/ions (named example) [1], move across membrane/cell wall [1], against a concentration gradient [1], using a carrier protein [1], requires energy [1], obtained through respiration [1]
Carries oxygen / forms oxyhaemoglobin [1], from lungs to cells/tissues [1] OR remove carbon dioxide [1]
No nucleus [1] therefore more space for oxygen [1], large surface area [1] for efficient oxygen absorption [or similar] [1]
Comparison of cost (dialysis more expensive long term) [1], lifestyle restrictions e.g. diet with dialysis [1], independent after transplant [1], low availability of transplant [1], donated kidney may be rejected / immunosuppressant drugs required [1]
Glucose enters the blood from digestive system/intestine etc. [1], glucose is filtered [1], reabsorbed [1] by active transport [1]
Ideas that: sugar has dissolved in moisture (on surface of fruit) [1], this solution more concentrated than solution inside fruit [1], osmosis [1], movement of water out of fruit [1], through partially permeable membrane (of fruit cells) [1]. any four for 1 mark each; allow explanations in terms of concentrations of water molecules for full marks
Large surface area [1], thin walls [1] therefore short diffusion distance [1], highly vascularised / good blood supply etc. [1]; all to maximise efficiency of gas exchange [1]
Oxygen more concentrated in blood leaving the lungs [1], 2.5x more [1]; carbon dioxide more concentrated in blood entering lungs [1], 1.125x more [1] (allow converse arguments)

6. Side 2 Mark Scheme
Advantages (max 3): reduced use of fossil fuels [1], less smoke produced [1], cheaper long-term [1], fertiliser produced [1], means of waste disposal [1], energy self sufficient [1]. Disadvantages (max 3): high initial cost [1], explosion risk [1], training required [1]
Increased sweat production [1], evaporation cools body [1]; vasodilation [1], heat loss (by radiation) [1]
Evaporation of water [1], from the leaves [1], through the stomata [1], causing a pull [1], so that water moves up the plant [1], = transpiration stream [1], water enters through roots [1] .
12500 [2] 1 mark for correct working if answer incorrect
Any three linked points from, less: links in food chain [1], energy lost at each link [1], energy lost in respiration [1], energy used to maintain body temp. [1], energy used in movement [1]
People will eat more food from plants (or converse) [1]; land available for food production is limited [1], meat will become more expensive [1], more people = less land for food production [1], land more expensive [1], demand for food will rise [1], greater demand for factory farming [1], farmers will need to improve efficiency [1]
Insulin released [1], by pancreas [1]; glucose converted to glycogen [1] in liver [1]
Any 4 features + explanation from: thicker cuticle to retain water [1], smaller surface area to reduce water loss/heat absorption [1], fewer stomata and closed in day to reduce water loss [2], widespread roots for water absorption [1], more water storage tissue [1]
Any five from: methane produced [1] by cattle [1] and rice fields [1]; more greenhouse gases [1], increased CO2 from transport/machinery etc. [1], deforestation releases CO2 [1] due to burning / less photosynthesis [1]; heat radiated from Earth is absorbed/reflected [1]
Need to remove extra CO2 [1], remove heat / cool down [1], anaerobic respiration has occurred [1], lactic acid produced [1], oxygen required to breakdown lactic acid [1] into CO2 and water [1]