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Credit biosphere objectives Errors made using the sampling technique of a quadrat Identifying the organisms wrongly – minimise this error by using a biological key Only using it once will not give a reliable result – minimise error by repeating it several times Errors made using the sampling technique of a pitfall trap Identifying the organisms wrongly – minimise this error by using a biological key Not checking it often enough as some organisms could get eaten – minimise this by checking frequently Errors that could be made using the measuring technique call a light meter People blocking the light – minimise this by moving them Only taking one reading – minimise this error by repeating the technique to give you a more reliable result Errors that could be made using the measuring technique call a moisture meter Probe not clean before use – minimise this error by cleaning probe before you use it to prevent contamination Only taking one reading – minimise this error by repeating the technique to give you a more reliable result The abiotic factors that could influence where an organism lives could be Intensity of light – some plants like a lot of light and others prefer to be in the shade Level of moisture – Could be more moisture at the bottom of a hill compared to the top and some plants prefer more moisture so live at the bottom and others prefer less moisture so live at the top How it works Explain the effect of removing one species from the food chain The organism could decrease if its predator numbers increase or it has less food to eat The organism could increase if its predators decrease or it gets more food to eat as less competition for food. Pyramid of numbers represents the number of organisms at each successive levels in a food chain Pyramid of biomass represents the mass of organisms at each successive levels in a food chain Growth curve under ideal conditions will keep increasing Nitrogen cycle Plants take in nitrates from the soil to give them a supply of nitrogen to make their proteins This protein can be passed up to the consumers (animals) in a food chain When the plant or animal dies or pass out waste microorganisms help recycle the nitrogen Dead organisms or waste decomposed by bacteria and fungi and this passes out ammonia Ammonia eaten by bacteria and pass out nitrite --- nitrification Nitrite eaten by different bacteria and they pass out nitrate which can now be taken in by the plants – back to the start decomposition Waste/ dead organisms nitrification ammonia nitrification nitrite nitrate Nitrogen cycle using nitrogen gas Nitrogen gas can be taken in by nitrogen fixing bacteria in the soil and they will pass out nitrates Nitrogen gas nitrogen fixation nitrates Lightning flash can also change nitrogen gas in atmosphere into nitrates which will end up in the soil Nitrates can be changed back into nitrogen gas by denitrifying bacteria in the soil --- plants do not like this as they want the nitrogen dentrification by bacteria nitrates nitrogen gas Leguminous plants – the lucky ones They have nodules on their roots which house their own nitrogen fixing bacteria and this gives them their own personal supply of nitrates Control and management Adverse effects of using fossil fuels in power plants Gives off CO2 gas which increases the greenhouse affect and acid rain Gives off SO2 gas which increases acid rain Adverse effects of using nuclear fuel in power plants Produces radioactive waste which could cause cancers Relationship between level of organic waste in the water and the number of micro-organisms As the organic waste increases the number of micro-organisms increases Relationship between the number of micro-organisms and the oxygen concentration As the number of micro-organisms increases the oxygen concentration decreases Relationship between the oxygen concentration and the number of species As the oxygen concentration decreases the number of species in the water decrease Indicator species An organism that indicates the level of pollution by their presence or absence Lots of lichens growing indicates a low level of SO2 pollution in the air Very few lichens growing indicates a high level of pollution Controlling components of an ecosystem to grow plants eg trees Habitat- the soil can be controlled by adding fertiliser Animals – eat our crop so control them using pesticides Plants – compete with our crop so control them with herbicides Investigating Living Cells Booklet 1 has no credit objectives Booklet 2 Investigating Diffusion Explain the importance of diffusion to organisms. This allows the organism to gas exchange Explain osmosis in terms of a selectively permeable membrane and of a concentration gradient. Water moving from a higher water concentration to a lower water concentration passing through a selectively permeable membrane Explain the osmotic effects in plants and in animal cells in terms of the concentration of the water in the solutions involved. Plants cells surrounded by a solution with a higher water concentration will take in water by osmosis and become TURGID Animal cells surrounded by a solution with a higher water concentration will take in water by osmosis and BURST (no cell wall to protect it) Plants cells surrounded by a solution with a lower water concentration will lose water by osmosis and become PLASMOLYSED Animal cells surrounded by a solution with a lower water concentration will lose water by osmosis and become SHRIVELLED UP Booklet 3 Investigating Cell Division Describe the stages of mitosis Each chromosome becomes two chromatids Chromosomes line up at the equator Spindles pull the chromatids apart Cytoplasm divides and becomes two daughter cells Explain why it is important that the chromosome complement of daughter cells in multicellular organisms is maintained. So that each cell has all the information to develop and function correctly Booklet 4 Investigating enzymes Explain the term specific as applied to enzymes and their substrate. Each enzyme has an active site (mouth) which only one substrate can fit into and no other. Degradation enzymes (speed up the breakdown of the substrate) Amylase enzyme – only starch fits into the active site Lipase enzyme- only Fats (lipids) fit into the active site Catalase enzyme – only hydrogen peroxide fits into the active site Pepsin enzyme – only protein fits into the active site Synthesis enzyme – (speed up the build up of new bigger substances) Phosphorylase enzyme – only Glucose –1-phosphate fits into the active site Explain the term optimum as applied to the range of conditions in which enzymes operate Optimum means the condition which the enzyme is most active. Enzymes in a range of temperature 0 - 40oC enzymes activity increases 40oC and above enzyme activity decreases Above 50oC the enzyme becomes denatured Enzymes in a range of pH – depends on enzyme Pepsin – active over a range of pH 1-7 optimum at pH of 2 Amylase – active over a range of pH 4 – 9 optimum of pH 7 Catalase – active over a range of pH 7-14 optimum at pH 12 Booklet 5 Investigating aerobic respiration State that oils contains more chemical energy per gram than carbohydrates or protein. Burning food experiment can prove this. Valid experiment (validity) Variable changed – type of food Variables kept constant – volume of water , mass of food and distance between burning food and water To make Results more Reliable – Repeat experiment Explain the importance of energy released from food during respiration to the metabolism of cells. Energy needed to allow all the chemical reaction to occur. Animal Survival The elements in carbohydrates Carbon Hydrogen and oxygen The elements in Fats (lipids) Carbon Hydrogen and oxygen The elements in Protein Carbon Hydrogen and oxygen and Nitrogen Carbohydrates are made of Glucose molecules Fats are made of Fatty acids and glycerol Proteins are made of Amino acids Digestion means The breakdown of insoluble foods into soluble foods Digestive juices are produced in the Salivary glands Stomach wall Pancreas Small intestine Liver Peristalsis The muscles behind the food contract and the muscles in front of the food relax Explain how the contraction of the stomach help the chemical breakdown of food. It mixes the food with the gastric juice ( pepsin and HCL acid) An amylase enzyme Salivary amylase starch A protease enzyme Pepsin Protein A lipase enzyme Pancreatic lipase fats maltose SAM amino acids fatty acids and glycerol FLAG A Villus - Many folds in the small intestine Thin epithelium Quick diffusion of digested food Blood capillary Transports absorbed glucose and amino acids Lacteal Transports absorbed fatty acids and glycerol Reproduction Explain the importance of internal fertilisation to land living animals The female body will always have liquid for the sperm to swim in Explain the relationship between the number of eggs / young produced and parental protection during fertilisation and development in fish and mammals The lower the number of eggs produced means that there is a higher degree of parental protection eg human females only produce one egg at a time which shows there is a very high degree of parental protection Describe the structure and function of the placenta Function – to exchange substances between the embryo and mother Structure Many folds – increase the surface area to allow more substances to exchanged Large blood supply – to transport the substances Thin – quick diffusion of substances Water and waste Explain the role of ADH in the regulation of water balance If the blood has a decrease in the water concentration then the pituitary gland will increase the production of ADH This will increase the permeability of the nephron tubule to water More water will be reabsorbed Urine volume decreases but the Urine concentration increases State the source of urea Urea is made in the liver How is urea transported to the kidney In the renal artery Artificial kidney (dialysis) Benefits – person stays alive Limitations – they have to be on the machine for several hours 3 times a week - must control what they eat when they are not on the machine Replacement kidney (transplant) Benefits – lead a fairly normal lifestyle Limitations – kidney can be rejected Responding to the environment Why do woodlice move more in dry conditions (stimulus) As they are trying to find a moist area so they do not dry up Why do woodlice move more in light areas As they are trying to find a dark area to hide from predators Rhythmical behaviour - follows a repeated pattern Hibernation or migration – stimulus is the decreasing length of daylight Significance – survives the winter when there is less food Nocturnal owl – stimulus is the onset of darkness Significance – will be active when their food is around Nocturnal mice – stimulus the onset of darkness Significance – will be active when they are better hidden from predators World Of Plants Credit objectives Introducing plants - Part 1 Explain the consequences to man and other animals of a reduction in the variety of species. Man - Less food / Less medicines / less raw materials Other animals - Fewer habitats to live in / less food to eat Describe a production or refining process Production of timber - grow trees in a nursery and then plants out on the hillside. If fertilisers need to be added to soil use a helicopter or plane. Cut some of the trees down (fell them) to reduce competition every 5 years. Finally cut all the trees down after 50 years. Use timber for building / paper etc Describe two potential uses of plants. New medicines or new food sources Growing plants - part 2 Describe the percentage germination that occur over a range of temperatures. 0 to 40 oC - percentage germination increases 40oC and above - percentage germination decreases Explain the structure of wind pollinated flowers in relation to sexual reproduction. Anthers outside flower to put the pollen in the wind Feathery stamens hang outside to catch the pollen in the wind Explain the structure of insect pollinated flowers in relation to sexual reproduction. Anthers inside the flower to put the pollen onto the insect when it comes into the flower. Stigma inside the flower to collect the pollen from the insect when it comes into the flower. Nectary gland produces nectar to attract the insect into the flower Describe the growth of the pollen tube and fusion of gametes The pollen lands on the stigma and grows a pollen tube. The male sex cell nucleus travels down the pollen tube and enters the ovule and fertilises the female nucleus. Describe fruits that use wind as a method of seed dispersal. The fruits have wings or fluffy parachutes to fly in the wind Describe fruits that use animal internal as a method of seed dispersal. The fruits are edible ( can be eaten and seed passes through the animal) Describe fruits that use animal external as a method of seed dispersal. The fruits have hooks to catch onto the outside of the animal Explain the advantage to humans of artificial propagation in flowering plants The plants with desired characteristic are produced (clones) A lot of the desired plant is quickly produced. Describe the term clone. A clone is genetically identical offspring to the parent. Describe the advantages of sexual reproduction to plants. Increases variation which increases the chances of survival if the environment should change Fruits can disperse the seeds which will allow the plant to colonise new areas Describe the advantages of asexual reproduction to plants. Quickly produces lots of plants, which cover the area and reduce competition with other plants. Does not involve all the stages of sexual reproduction so more chance to survive. Making food - part 3 Describe the structure of phloem. Have sieve cells with sieve plates and companion cells. State the function of phloem Transports food Describe the structure of xylem Long, hollow tubes with lignin State the 2 functions of the xylem vessels Transport water and minerals + support for the plant Describe features of the leaf that allow it to be efficient at gas exhange Thin - quick diffusion of gases Lower epidermis has stomata, which allow gas exchange between leaf and atmosphere. These are controlled by guard cells. Spongy mesophyll - these cells have circular shape to allow quicker diffusion of CO2 to the palisade mesophyll cells above Veins on the leaf - these are the vascular bundles that contain the xylem and phloem Describe the fate of CO2 as structural and storage carbohydrates in plants and as an energy source. CO2 will end up in the glucose made during photosynthesis and this can be glucose can be used for respiration ( providing energy) This glucose can then be changed into a storage carbohydrate called starch The glucose can also be changed into a structural carbohydrate called cellulose. Explain what is meant by a limiting factor. This is something that is in short supply to the plant and if increased will increase the rate of photosynthesis. State the 3 main limiting factors in photosynthesis. Light intensity CO2 concentration Temperature Remember the rule if using a graph to find a limiting factor If the graph is rising the limiting factor is on the X axis (look down) If the graph is level then it is not the factor on the X axis so you have to look up to the graph above Inheritance Credit objectives Part 1 Explain what is meant by discontinuous variation It is a variation that falls into 2 or more distinct groups Explain what is meant by continuous variation It is a variation that falls within a range of values Part 2 State that the parents in experimental monohybrid crosses are usually true breeding and show different phenotypes of the same characteristics. Example of this would be - Tall plants (TT) crossed with dwarf plants(tt) TT X tt Predict the proportions of the phenotypes of the F2 offspring of a monohybrid cross The parents would be Tt (Tall) X Tt (Tall) The F2 ratio would be predicted as 3 Tall : 1 dwarf Know the definition of alleles. Alleles are different forms of a gene Explain the differences between observed and predicted figures in a monohybrid cross. This is due to the fact that fertilisation is a random process. Part 3 Describe one animal example of the enhancement of a characteristic through selective breeding. Cattle -- enhanced milk yield OR enhanced meat production Describe one plant example of the enhancement of a characteristic through selective breeding. Sunflower plant -- enhanced oil production Give an example of a chromosome mutation, advantageous to humans. Polyploid plants are caused by a chromosome mutation and have increased yield of crop and are bigger and stronger than the normal plants Give an example of a factor which can influence the mutation rate in an organism. X rays / UV light / certain chemicals eg mustard gas Biotechnology Credit objectives Describe the process of anaerobic respiration in yeast cells. Sugar energy + CO2 + alcohol Compare anaerobic respiration with aerobic respiration in yeast cells. Anaerobic respiration provides less energy and the by products are CO2 and alcohol instead of CO2 and water Describe how the commercial brewers provide the best growing conditions for yeast. They provide the optimum temperature and pH for optimum enzyme activity Explain what is meant by batch processing All ingredients are added at the start and the product is removed at the end. Explain the need for malting of barley before use by the brewing industry. The starch in the barley grain is changed into maltose sugar and the yeast cells use this sugar. Explain the souring of milk in terms of bacterial fermentation of lactose. The bacteria use the lactose sugar to provide them with energy and pass out lactic acid, which makes the milk sour. Explain the precautions, which are taken during the manufacturing process with reference to resistant fungal and bacterial spores. They have to use very high temperatures (121oC) or strong chemicals Describe the part played by bacteria in the nitrogen cycle Bacteria are involved in decomposition (waste to ammonia), nitrification (ammonia to nitrite and then to nitrate). Also denitrification (nitrate to nitrogen gas) and nitrogen fixation (nitrogen gas to nitrates) Describe the part played by bacteria in the recycling of carbon. Bacteria release the carbon as CO2 during decomposition of waste, which can be taken in by the plants for photosynthesis. Explain the process of decay in terms of the energy requirements of micro-organisms The micro-organisms use the waste as an source of energy Explain why complete breakdown of sewage is only possible in aerobic conditions. Because oxygen is needed for the complete breakdown of sewage Explain why a range of micro-organisms is needed to breakdown the range of materials in sewage. A range of micro-organisms are used to make sure all the material in the sewage is completely broken down. Explain the advantage of upgrading waste Waste can be changed into either, a high protein food (whey into cattle feed) or into a high energy fuel (manure into methane gas) Explain genetic engineering in terms of manipulation of chromosomal material. Locate insulin gene and cut it out of the DNA. Remove plasmid from bacterial cell and cut open Add insulin gene to plasmid and replace into bacterial cell Genetically engineered bacteria now multiply and produce insulin, which can be purified State that as a result of genetic engineering, bacteria can produce large quantities of insulin very quickly Learn the above statement Why do we now need more insulin produced by biotechnology. As there are more people with diabetes now What are the two advantageous of producing new genotypes by genetic engineering compared to selective breeding. It is quicker and almost guaranteed to produce the new genotype What are the two main advantages of using biological detergents compared to non-biological? Washing is at lower temperatures, which saves energy/money and protects delicate material Explain the action of biological detergents in terms of digestive enzymes. Biological detergent contains digestive enzymes, which were made by genetically engineered bacteria. These enzymes breakdown the stains on the clothes. Describe the advantages of using immobilisation techniques. The enzyme or yeast can be put into a jelly bead, which will be able to be used over again and also be removed from the product. Explain how continuous flow processing uses immobilisation and the advantages this has over the batch processing. Only continuous flow processing uses immobilization as it allows the enzyme or yeast to be used many times and it will remain in the process as the product is removed. The body in Action Credit objectives Movement Describe the structure of a synovial joint and state the function of its parts. Cartilage ( at the end of the bones) Acts as a shock absorber and reduces friction at the joint Synovial fluid Reduces friction at a joint Synovial membrane Produces synovial fluid Ligament Holds the bones in place at a joint State that bone is formed by living cells. Learn the above statement Explain why tendons are inelastic. So the pull of the muscle is transferred to the bone Explain the need for opposing muscles at a joint One muscle contracts to bend the limb and the other muscle contracts to straighten the limb The Need for Energy Describe the mechanism of breathing in humans To inhale - intercostal and diaphragm muscles contract this increases the volume and decreases the pressure air moves into the lungs To exhale - intercostal and diaphragm muscles relax this decreases the volume and increases the pressure air is pushed out of the lungs Explain the function of the mucus in trachea and bronchi tubes This traps the dirt and germs in the inhaled air Explain the function of the cilia in the trachea and bronchi tubes. This pushes the mucus out of the lungs Describe the gas exchange between the air sacs and the surrounding blood vessels. Oxygen diffuses from the air sacs to the blood and carbon dioxide diffuses from the blood to the air sacs Describe the features, which make the lungs efficient gas exchange structures. Large surface area; thin walled air sacs; good blood supply; always moist Explain the function of haemoglobin in the red blood cells This helps the red blood cells transport oxygen. Describe the features of a capillary network, which allow efficient gas exchange. One cell thick; large surface area; come close to all the body cells Co-ordination Explain the relationship between judgement of distance and binocular vision Each eye sends a different image to the brain, which can then create a 3 dimensional picture to judge distances better. Explain how the arrangement of semicircular canals is related to their function Each fluid filled canal is set at right angles to each other This detects movement in all directions Describe how a reflex action works, using a simple model of a reflex arc. State the central nervous system sorts out information from the senses, and sends messages to those muscles to take the correct response. Learn the above statement Know the function of the cerebrum in the brain. For memory, reasoning, sight, sound Know the function of the cerebellum in the brain. For balance and co-ordination Know the function of the medulla Controls automatic actions eg breathing, heart beat. Changing levels of performance Explain muscle fatigue in terms of anaerobic respiration Muscle cells have no oxygen so produce lactic acid instead of CO2 and H2O State that training improves the efficiency of the lungs circulation Learn the above statement Explain the relationship between the effects of training and recovery time. Training makes the lungs larger so more oxygen diffuses into the blood and also the heart muscle is stronger and can push a greater volume of blood each time