Topics – B3 Unit 1 ………………….’s Revision cards Print out. Fold left to write and test yourself / get someone to test you!! NB: The topics in green are the ones you should revise for the end of year test. Osmosis (Q) 1. Name three ways substances can move in and out of cells 2. Describe osmosis 3. What is a partially permeable membrane? 4. What happens to plant cells when they are put into a weak solution / water? 5. What can happen to animal cells when put into a very dilute solution? 6. Why do animal cells but not plant cells burst when they take up water? Osmosis Sports drinks Active transport Exchange surfaces Gas exchange in the lungs Exchange in plants Rates of transpiration The circulatory system The heart Arteries and veins Capillaries Blood Blood cells Transport in plants Osmosis (A) 1. Osmosis, diffusion, active transport 2. The movement of water from a high to low concentration down a concentration gradient across a partially permeable membrane. 3. A membrane with small holes that allows some substances (like small water molecules) to pass through but will not allow larger molecules through. 4. The pressure in the cells will increase as water will enter via osmosis. 5. Water will enter animal cell via osmosis but they can burst (called lysis) 6. Plant cells have a cell wall which prevents the cell from bursting. Animal cells do not have a cell wall Sports Drinks (Q) 1. Why do humans need water? 2. What is the recommended intake of water for adults? 3. When would you need more water? 4. What substances do you lose when you sweat? 5. Why do we sweat more when we exercise? 6. What do sports drinks contain? (Don’t worry about q.7) 7. What are the three types of sports drinks? Active transport (Q) 1. What are the three features of active transport that makes it different from other methods? 2. What is the energy used for in active transport? 3. Give examples of where active transport may occur 4. Explain how active transport enables mineral ions to be taken up by the plant roots Sports Drinks (A) 1. To prevent dehydration. Cells do not function properly without water. To protect organs, substances are dissolved in water, temperature regulation, lubricate the joints. 2. Two to three litres of water per day to remain hydrated 3. During exercise, hot day (sweat more). 4. Water and salt ions. 5. When we exercise we use energy which is released from sugars during respiration. This generates heats, so to cool your body you sweat. 6. Water – hydration, carbohydrates – for energy, mineral ions – healthy muscles, caffeine – stimulant 7. Hypotonic – hydration, isotonic – fuel and hydration, hypertonic - fuel Active transport (A) 1. Against a concentration gradient (from low to high), requires a carrier protein to pass through the membrane, Requires ATP (energy) from respiration. 2. To change the shape of the protein carrier 3. Plant roots, the villi of the small intestine, the absorption of sugars from cells 4. Mineral ions are at low concentration in the soil, lower than in the plant cells. The minerals cannot move into the cell by diffusion. They use active transport. Exchange surfaces (Q) 1. Why does the process of exchange become inefficient in larger organisms? 2. Give examples of different exchange surfaces 3. What are the three main features of exchange surfaces? Gas exchange in the lungs (Q) 1. Where does gas exchange in the lungs occur? 2. Which gases are exchanged in the lungs? 3. What causes the ribcage to move up and down during ventilation? 4. What is the role of the diaphragm when you breathe in? 5. What is the percentage of oxygen and carbon dioxide in inhaled and exhaled air? Exchange surfaces (A) 1. Their surface area to volume ratio becomes smaller so exchange in harder 2. Surface of the lungs (alveoli), the surfaces of gills, the digestive system (villi in the small intestine), the leaf (gases), plant roots. 3. Large surface area, thin surface (short distances), excellent blood supply maintains concentration gradient), Gas exchange in the lungs (A) 1. The alveoli 2. Oxygen and carbon dioxide 3. The intercostal muscles contract, this causes the ribs to move up and expands the thorax 4. The diaphragm flattens expanding the space in the thorax decreasing the pressure so air rushes in 5. Inhaled air – Oxygen 21%, carbon dioxide 0.04%. Exhaled air – oxygen 17%, carbon dioxide 4% Gas exchange in plants (Q) 1. By what process does water move into the plant roots? 2. Where does water enter and leave a plant? 3. State two uses of water by the plant 4. How can plants reduce water loss? 5. How do the guard cells control the water loss through the stomata? 6. What substances are exchanged through the stoma? 7. What is transpiration? Rates of transpiration (Q) 1. What factors affects the rate of transpiration 2. What is used to measure the rates of transpiration? 3. Why do gardeners need to water their plants more in summer? 4. Why will sand dune plants loose more water than woodland plants? 5. Why do florist spray their plants will water? Gas exchange in plants (A) 1. Osmosis 2. Enters through the roots, leaves through the stomata in the leaves 3. Water is used for photosynthesis, when water leaves the plant it cools the plant, helps to support the plant, transports dissolved minerals 4. Most stomata are on the underside of the leaf (the coolest part), the guard cells will close the stoma. 5. When there is plenty of light and water the guard cells swell and become firm by osmosis this causes them to bend and opens the stoma. When there isn’t enough water the guard cells lose water via osmosis and cannot open. 6. Water vapour leaves the plant, carbon dioxide enters the leaf if the stoma are open and used for photosynthesis, oxygen leaves through the stoma produced as a byproduct of photosynthesis 7. Water flows up the stem and through the leaves before leaving the leaves by evaporation via stoma Rates of transpiration (A) 1. Light intensity, temperature, air movement, humidity. 2. A photometer 3. The rates of transpiration will be greater because the stomata are open allowing more gas exchange for photosynthesis 4. Sand dunes are windier and will carry the evaporated water molecules away from the leaf increasing the concentration gradient. 5. Increasing the humidity prevents plants loosing water by reducing the concentration gradient The circulatory system (Q) The circulatory system (A) 1. Name three substances that blood carries to your body cells 2. Name two substances that blood carries away from your body cells 3. What are blood expanders and when might they be used? 4. What are oxygen carriers? 5. Why might the remaining haemoglobin in a trauma patients blood be enough to sustain a motionless patient but not a mobile one? 6. Give the advantages of artificial blood products 1. Oxygen , glucose, amino acids, nutrients, 2. Urea, carbon dioxide, 3. Sterile saline solutions that maintain normal blood pressure so blood can flow if patients have lost a lot of blood. Used in emergency situations 4. If two thirds of your blood is lost you would need artificial blood that would carrier oxygen. Can be chemicals that release oxygen or can be encapsulated haemoglobin 5. Motionless patients will not need as much energy and will respire less needing less oxygen 6. Don’t have to be matched to patients, useful for treating war casualties, in countries where transfusions aren’t safe (not screened for disease), for trauma patients, can be stored for three years at room temp, immediately restore full oxygen carrying capacity (real blood takes 24hrs) The heart (Q) The heart (A) 1. What are the names of the four chambers of the heart 2. Which side pumps oxygenated blood to the body? 3. What is the artery called that carries oxygenated blood to the body? 4. Which artery pumps deoxygenated blood to the lungs? 5. Which blood vessels carries deoxygenated blood towards to the heart? 6. Why are artificial heart valves made of inert materials? 7. Why would the risk of rejection be a serious problem if artificial hearts had a capillary blood supply? 1. The right and left ventricle, the right and left atria 2. The left side 3. The aorta 4. The pulmonary artery 5. The vena cava 6. Prevents corrosion / reaction sin the body. Smooth to prevent blood clots 7. The white blood cells would patrol the heart and attack it if the artificial heart had a capillary blood supply Arteries and Veins (Q) 1. Why is the lining of the arteries folded? 2. Why does measuring you pulse allow you to measure your heart rate? 3. Identify the features of veins 4. Identify the features of arteries 5. What is a stent? 6. Who might need a stent? Capillaries (Q) 1. Describe the structure of the capillaries 2. What is the function of the capillaries? 3. What substances are carried to your cells by the capillaries? 4. What waste substances do the capillaries remove from the tissues? Arteries and Veins (A) 1. Allows them to stretch and recoil when blood enters and is pumped under high pressure 2. Each pulse corresponds to each beat of your heart 3. Usually carry deoxygenated blood back to the heart. Large lumen, have valves to prevent backflow, smooth lining, thin walls, little muscle or elastic as the blood is under low pressure 4. Usually carry oxygenated blood away from the heart. Elastic fibres, muscle fibres, narrow lumen, folded inner lining that expands with each high pressure blood spurt. 5. A narrow mesh tube that can be inserted into blocked / narrowed artery to widen the lumen and allow the blood to flow through. 6. People at risk of a heart attack due to narrowed arteries blocked by saturated fat deposits. Capillaries (A) 1. Their wall is one cell thick for efficient exchange, blood is under low pressure so as not to damage the blood vessels, lumen diameter is wide enough to let one red blood cell through at a time. Blood flow is very slow, form vast networks at the tissues of every organ – they have a large surface area. 2. To deliver blood to your tissues allowing exchange of substances 3. Oxygen for respiration, glucose for respiration, amino acids for growth and repair, other nutrients like fatty acids, water – hydration and hormones. 4. Carbon dioxide, lactic acid (anaerobic respiration), urea, spent hormones, heat Blood (Q) Blood (A) 1. 1. What makes blood a unique tissue? 2. 2. Where in your body is blood made? 3. 3. State three functions of the blood 4. 4. Name four substances carried in your blood 5. 5. Name four substances dissolved in plasma 6. 6. How does your blood protect you? 7. How does your body regulate heat? 7. 8. Why is it important to maintain a 8. constant pH? Blood Cells (Q) 1. What is the function of red blood cells? 2. How are red blood cells adapted to their function? 3. What are the functions of white blood cells? 4. Why can’t red blood cells divide? 5. Where are old red blood cells broken down? 6. What do platelets do? It is the only tissue on your body that is a fluid The bone marrow transport, protection, regulation of body temperature and pH oxygen, carbon dioxide, glucose, amino acids, hormones, cholesterol, mineral ions, antibodies, fatty acids carbon dioxide, glucose, amino acids, hormones, cholesterol, mineral ions, antibodies, fatty acids Blood clots forming scabs at wounds to prevent microbes entering and stops blood loss. White blood cells fight invading pathogens Distributes heat from respiring muscles to other organs and your skin Enzymes require a specific pH to function or they will change shape (denature) Blood Cells (A) 1. To carry oxygen to your tissues for respiration 2. They are biconcave – large surface area, no nucleus – more space for oxygen, contain haemoglobin which forms oxyhaeomoglobin when combined with oxygen. 3. Defence against pathogens. Produce antitoxins and antibodies. Some ingest foreign particles. 4. They have no nucleus 5. The liver 6. Small cell fragments no nucleus. Help the blood to clot. Made in the bone marrow. Transport in plants (Q) 1. What are the two vascular bundles of plants? 2. What do the vascular bundles do? 3. What do the xylem do? 4. What do the phloem do? 5. What is transpiration stream? 6. What is translocation? Topics – B3 Unit 2 Keeping internal conditions constant The kidney Renal dialysis Kidney transplants Decreasing body temperature Increasing body temperature Regulating glucose levels Type 1 diabetes Human populations Pollution Deforestation Global warming Biofuels Microbes and food production Food chains and food production Fishing Transport in plants (A) 1. Xylem and phloem 2. Transport substances from the roots through the stem to the leaves and they provide support. 3. Dead cells stacked on top of each other forming long hollow tubes. They transport water and dissolved substances from the roots to the leaves 4. Living cells that form tubes and transport food substances in both directions 5. The continual transport of water from the roots to the leaves by xylem 6. The transport of sugars made by photosynthesis in the leaf to areas where the plant needs it – for storage / growing areas by the phloem Keeping internal conditions constant (Q) 1. If your muscles respire anaerobically which waste product do they produce? 2. How is the waste product of anaerobic respiration harmful if it isn’t removed? 3. What is the process called where waste products are removed from the body 4. Name five internal conditions that must be kept constant 5. What does ammonia react with to make urea? 6. How is urea harmful to the body? 7. Why must temperature be regulated? 8. Why must blood sugar be regulated? The kidney (Q) 1. 2. 3. 4. 5. 6. 7. 8. Keeping internal conditions constant (A) 1. Lactic acid 2. Increases blood pH which can prevent enzymatic reactions 3. Excretion 4. pH, Water, ion content, temperature, blood sugar levels 5. carbon dioxide 6. makes the blood alkaline which affects the enzymes 7. Proteins and cell membranes would become damaged above or below 36 – 37.50C 8. Needed for respiration. Too little – tired and faint. Too much and water would leave the cells by osmosis The kidney (A) How is urea made in the body? 1. Proteins digested into amino Which organ removes urea? acids. Excess amino acids are carried by the How is urea transported from the liver blood to your liver and are converted to to the kidneys? ammonia. This reacts with carbon dioxide Why is the glucose that is filtered from and it becomes urea. the kidneys reabsorbed? 2. The kidneys Apart from urea what else does the kidney regulate? 3. Via blood How would a high protein diet affect 4. Glucose is useful for respiration the levels of urea? 5. Excess salt ions and water How would the water content of your Increase the amount of urea urine change if the weather was hot but you didn’t 6. 7. Urine would be very drink any water concentrated, little water How would your urine change if you ate a very salty meal? 8. The urine would become very salty. Renal Dialysis (Q) Renal Dialysis (A) 1. What is renal failure? 2. Explain the difference between acute and chronic renal failure 3. Why does the renal dialysis fluid have to be sterile? 4. Why is the dialysis fluid at body temperature? 5. Why is heparin added to the patients blood before the blood enters the dialysis machine? 6. Why does the dialysis fluid contain glucose at the same concentration as a healthy human? 7. Why does the renal dialysis fluid have to be changed after a dialysis session? 1. Condition where the kidneys don’t function properly 2. Acute – sudden, but treatable. Usually caused by an infection or drugs. Chronic – long lasting and patients will not recover. Could be genetic or due to diabetes. Symptoms include sickness, paralysis, back pain, anaemia, swollen limbs 3. To prevent infections 4. To prevent the patient loosing or gaining heat 5. It is an anticoagulant which prevents the blood from clotting 6. So that the concentration of glucose will not change – it won't diffuse through the membrane 7. The dialysis fluid will contain the patients excess salt and water 8. Renal failure disrupts the ion concentration in the cells and so cells may take up extra water to balance the concentration inside the cells which contain excess ions Kidney transplants (Q) 1. What are the advantages of having a kidney transplant compared with renal dialysis? 2. What precautions do medical teams take to reduce the risk of rejection when transplanting a kidney? 3. Why are transplant patients more at risk of infection? 4. Explain why a recipient may reject a transplanted kidney? Kidney transplants (A) 8. Why do you think people with renal dialysis get swollen ankles, feet, face and legs? 1. improved quality of life (no more dialysis 4 times per week, can go on holiday) / Cheaper for NHS to transplant 2. Tissue type the patient and the donor, match blood types closely 3. They have to take immunosuppressant drugs to prevent the immune system attacking the transplanted organ 4. The recipients immune system can recognize that the antigens on the transplanted kidney are not their own. The white blood cells would then attack and destroy the organ Decreasing your body temperature (Q) 1. Why can exercise cause us to overheat? 2. Why can dehydration increase the chance of overheating? 3. How does sweating cool you? 4. Why does your skin look and feel red and hot when you are overheating? 5. Why should we drink more during hot weather? 6. Describe vasodilation 7. Where is the thermoregulatory centre? 8. How do dogs cool themselves? 9. Elephants and rabbit have large ears, how does this help them to cool? Decreasing your body temperature (A) 1. Increases respiration which produces heat as a byproduct 2. Water needed to distribute the heat in our blood between our organs and to the skin where the heat can radiate out. Water is needed for sweat 3. Sweating cools the body because the water evaporates and takes the heat away with it. 4. The blood vessels open wide to let the heat radiate from the surface 5. We sweat more so we need to replace the water 6. Nerves stimulate the blood vessels that supply the capillaries in the skin. They dilate and this allows more blood to flow to the surface. The excess heat radiates away from the body 7. The brain 8. They pant instead of sweating 9. Large surface area allows the heat to radiate away from their bodies. Increasing your body temperature Increasing your body temperature (Q) (A) 1. Enzymes will not work properly and chemical 1. Why is it dangerous if your core reactions will slow down. You will become body temperature drops below hypothermic 0 35 C 2. Reduced heat loss by evaporation 3. Outside in cold weather too long, immersed in cold 2. Why does reduced sweating water, elderly, a baby (large surface area to prevent you from overcooling volume ratio 3. State two reasons why you may 4. Stimulates the skeletal muscles to contract and relax quickly which requires energy from overcool? respiration. Respiration produces heat. 4. How does shivering warm you up? 5. The arterioles that supply the capillaries near the 5. What is vasoconstriction? skin contrast preventing blood flowing at the skins surface. Your skin will look pale and feel cold. This conserves heat and protects internal organs from heat loss and damage. Prolonged exposure would result in frost bite Regulating blood glucose levels (Q) 1. Explain why blood glucose level rises after you have eaten a meal? 2. Why does your blood glucose level drop when you have not eaten for several hours? 3. Explain why your blood glucose level drops after you have been swimming? 4. Which organ monitors your blood glucose levels? 5. Which hormone is released into your blood when your blood glucose level rises above normal levels? 6. Which hormone is released into your blood when your blood glucose levels are lower than normal? 7. What does insulin do? 8. Which of the are carbohydrates and which are proteins? Glucagon, glucose, glycogen, insulin Type 1 diabetes (Q) 1. What is type 1 diabetes? 2. How is type 1 diabetes treated? 3. What would happen if people with type 1 diabetes did not get treatment? 4. What causes type 1 diabetes? 5. Why do people with diabetes urinate very frequently? Regulating blood glucose levels (A) 1. the digested carbohdrates (glucose) enters your blood via the walls of the small intestine 2. The glucose is used up during respiration 3. Exercise usues energy which is made during respiration. Glucose is needed for respiration 4. The pancreas 5. Insulin 6. Glucagon 7. Insulin promotes the uptake of glucose into cells. Takes excess glucose to the liver to be stored as insoluble glycogen 8. Carbs: Glucose, glycogen. Proteins: Glucagon, Insulin Type 1 diabetes (A) 1. Where patients do not make enough insulin and so blood glucose level is not controlled. 2. Injections of insulin into blood after meals, eat regular high fiber meals, monitor blood glucose levels, avoid alcohol, take regular exercise 3. Blindness due to retina damage, poor wound healing, ulcers, increased risk of stroke, increased risk of heart attack 4. Cells of the patients immune system destroy the special cells in the pancreas which produces insulin. Could be caused by viral infection, cows milk in early life, certain antibiotics and trauma injury or pancreatic tumours. 5. When the kidneys filter the blood too much glucose is filtered out and the kidneys do not reabsorb the glucose. Glucose passes out of the urine and a lot of water goes with it. This is also why diabetics feel very thirsty Human Populations (Q) Human Populations (A) 1. Many children died young, lack of contraception 1. Families had large numbers of 2. Diet improved, hygiene improved, healthcare children before 1900. Suggest improve, infant mortality fell 3. Shortage of food in some countries, more land why? being used for farming and building, more pollution 2. After 1900 there was a dramatic being produced, the world’s resources are being used faster than they can be replaced rise in the population. Suggest 4. Sustainable means using resources for human reasons why needs without harming the environment 5. Recycle, replace resources where possible (plant 3. Population increase has negative new trees), avoid over use of resources if they effects on the environment. cannot be replaced quickly eg fishing quotas. Use Suggest these negative effects. alternative fuels 4. Describe the meaning of the term sustainable? 5. How can humans manage their use of resources? Pollution (Q) Pollution (A) 1. Cows produce methane – greenhouse gas which 1. List three ways in which farming contributes to global warming, the use of can damage the environment fertilisers can run off the soil polluting the rivers 2. How does sulphur dioxide produce which can cause eutrophication and the use of pesticides / herbicides which can wash into acid rain? waterways and build up in the food chain to toxic 3. What is the affect of carbon levels dioxide released from cars 2. The sulphur dissolves in rain to form acid rain 3. This greenhouse gas contributes to global factories, burning wood? warming 4. Why are people in towns only 4. Smoke causes smog and the smoke particles can allowed to burn smokeless fuel? cause bronchitis or prevent photosynthesis 5. What are the problems with CFCs? 5. CFCs damage the ozone layer allowing more UV rays in Deforestation (Q) 1. 2. 3. 4. 5. 6. 7. 8. State two major reasons for deforestation What are the effects of deforestation? What is peat? What are the negative consequences of destroying and removing peat from peat bogs? How do trees prevent erosion? Why is the drugs industry concerned with deforestation? How could humans use wood more sustainably? Explain three ways in which deforestation results in carbon dioxide release Global warming (Q) 1. Which two gases are the main greenhouses gases? 2. What are the major sources of these gases? 3. Why has there been an increase in the two major greenhouse gases? 4. Why is global warming affecting the polar bear distribution? 5. How can carbon dioxide be removed from the atmosphere Deforestation (A) 1. 2. 3. 4. 5. 6. 7. 8. To provide timber for furniture, building and fuel and for creating land for farming / building Increases CO2 (global warming), loss of biodiversity, soil erosion, loss of future resources Produced over thousands of years from moss in wet acidic boggy areas. It is very rich in nutrients and has been dug up and sold for compost loss of a diverse habitat, when the moss is aerated it begins to decay which releases carbon dioxide into the atmosphere and contributes to global warming No tree roots to hold the soil in place. No trees to take up the water. Some undiscovered species will become extinct before their properties have been researched for medicinal properties, to treat diseases. Recycle wood / paper products. Plant new trees for every tree cut down. Slash and burn – removing the trees which take in carbon dioxide when they photosynthesize. Burning the trees which release carbon dioxide when they burn. The release of carbon dioxide from the microbes that decompose the decaying material Global warming (A) 1. Methane and carbon dioxide 2. Methane from cattle farming and rice paddy fields. Carbon dioxide from increased combustion (burning) of fossil fuels to supply us with energy. 3. Increased combustion demand for energy. Increased demand for meat – more farming 4. Global warming is increasing sea temperatures which melts the ice caps. Polar bears have less ice to live on 5. Trees and plants take up carbon dioxide by photosynthesis Biofuels (Q) 1. What is the energy source for making biofuels? 2. Name the three types of biofuels 3. State the advantages and disadvantages of biofuels 4. Why is biogas from landfill sites particularly dangerous? 5. Why is gasohol used in Brazil? 6. Why do we describe biogas as carbon neutral? Biofuels (A) 1. The sunlight used in photosynthesis 2. Wood, Biogas, Bioethanol, 3. Advantages: Reduces fossil fuel usage by providing an alternative fuel, no overall increase in the level of carbon dioxide, doesn’t produce particulates. Disadvantages: habitat loss, extinction of species. 4. It could explode 5. Lots of sugar cane – can be made into bioethanol 6. The carbon dioxide taken in during the growing of the biofuels in photosynthesis is released again when the fuel is burnt Microbes and food production (Q) Microbes and food production (Q) 1. Name a fungi that can be eaten 1. Mushrooms directly 2. Alcohol and bread 2. Name two food products produced 3. A high protein low fat meat by yeasts substitute that can be flavoured 3. What is mycoprotein? made from a fungus 4. What conditions must be kept 4. The pH and the temperature constant in the production of 5. High protein, high fibre, low fat. mycoprotein? 5. How nutritional is mycoprotein? Food chains and food production (Q) Food chains and food production (A) 1. How is energy lost from a food chain? 2. Why is it more efficient for humans to eat herbivores and producers rather than carnivores 3. How do farmers maximize energy transfers? 4. How would controlling the temperature of animals reduce energy loss? 5. How would reducing movement reduce energy loss? 6. List the advantages of energy efficiency farming 7. List the disadvantages of energy efficient farming 1. movement, keeping warm, excretion, reproduction 2. Shorter food chain means less energy is lost. Carnivores will not contain as much energy 3. Reduce animal movement / control the temperature of their animals 4. Warm: Reduce heat loss, less energy wasted in keeping warm. 5. Reduced respiration 6. Less energy transferred out of the food chain, more available for human consumption, less labour intensive, less risk of attack from predators like foxes, cheaper to produce 7. Greater risk of disease spreading between animals, inhumane / cruel, poor quality product Fishing (Q) 1. What technological advances led to overfishing? 2. Which fish species are caught in UK waters? 3. Which fish species is most likely to disappear from the North Atlantic? 4. What actions have governments taken to prevent overfishing? 5. How effective have these strategies been? 6. What is the disadvantage of these strategies? Fishing (A) 1. Sonar to locate the fish, sophisticated nets designed to prevent fish escaping, well designed boats that can travel long distances and can store fish in big freezers 2. Herring, haddock, cod and mackerel 3. Cod 4. Net size – larger holes to allow younger fish to escape and breed – replenish the population and fishing quotas – prevent endangered species from being overfished 5. Fishing in the North sea is now sustainable. Fishing has been reduced to a level where the fish populations are able to recover. 6. Fishermen are suffering unemployment