Investigating the rate of photosynthesis in pondweed.

Investigating the rate of photosynthesis in pondweed Possible variables and preliminary work Variable High Explained Low Light intensity 9 mm3/min of O2 I found that changing the light intensity was good as it gave good results. 7.5 mm3/min of O2 CO2 concentration 0 mm3/min of O2 I found that concentration gave a good range of results and it would also be interesting to investigate this one. 5.8 mm3/min of O2 Temperature 8.3 mm3/min of O2 Temperature gave a small range of results and is unreliable as the temperature would always be changing. 8.4 mm3/min of O2 Volume of water 8.6 mm3/min of O2 The volume of water did not give a good range of results. 7.9 mm3/min of O2 Chosen Variable My chosen variable is concentration of CO2 because it gave me a good range of results and it is a main factor of photosynthesis. Fair Testing To keep this a fair test I will change only my chosen variable and keep all other variables the same. Safety To ensure safety I will bare these things in mind and check that everything is safe before and during the experiment. I will be careful of water and electricity, lamp becoming hot, handling glass and sodium hydrogen carbonate. Apparatus * Photosynthometer * Clamp * Sodium hydrogen carbonate * Lamp * Pond weed * Beaker * Water Diagram Procedure We will set up the apparatus as shown in the diagram above. We

  • Word count: 1064
  • Level: GCSE
  • Subject: Science
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To find the most efficient but simple method of keeping a Hot Water Tank Warm for 20 minutes.

Science coursework Hot Water Tank: It's Gettin' Hot In Here!! By Nazreen Kosar Hussain Planning Task Title To find the most efficient but simple method of keeping a Hot Water Tank Warm for 20 minutes. Aim My aim is to find the easiest yet most successful way to keep a Hot Water Tank warm for 20 minutes. Scientific Background Heat flows when there is a difference in temperature. It flows from the hotter region to the cooler region therefore making both regions equal in temperature. There are three ways in which this can happen. -Conduction Conduction is when vibrating particles pass on their extra vibration to their neighbouring particles. This only happens in solids e.g. a wooden spoon. 2-Convection Convection is when a liquid or a gas moves from a hotter region to a cooler region e.g. water. 3-Radiation This happens through waves. Radiation waves only travel in vacuums e.g. from the sun to earth. Insulators These are different materials that allow different amounts of energy to travel through them. A good conductor is that which allows heat to flow through it easily. A bad conductor is that which doesn't allow heat to flow through it easily. Evaporation This is when a liquid changes state into a gas. Boiling a liquid normally does this. Variables Independent variables are the ones that I cannot keep at a certain amount. Dependent variables are the ones

  • Word count: 870
  • Level: GCSE
  • Subject: Science
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To find out whether maggots respond in proportion to light intensity.

Stacey Beard 23 January 2001 0BL Response to Stimuli Aim: to find out whether maggots respond in proportion to light intensity. Prediction I predict that a maggots photoreceptors respond to different intensities of light, and that when the light is more intense the receptors send an electrical message down the maggots nervous system, which makes the maggot move faster than it would if the light was less intense. In a previous experiment the further away the light source was the slower the maggot took to move away five centimetre. This is an example of photokinesis. If the maggots speed remained the same whatever the light intensity then this would be an example of phototaxis. Equipment Stopwatch Boss and Clamp Light with 100 watt bulb Three Maggots Graph Paper Compass Plan To test this theory I am going to time how long it takes a maggot to travel 5 centimetres varying the intensity of the light. To make sure that my test is fair I will only have one variable and that is the height of the light source from the maggots. This will produce different light intensities. My constant will be the distance the maggot has to travel and the distance the clamp stand which holds the light is away from the maggot. To make sure my

  • Word count: 490
  • Level: GCSE
  • Subject: Science
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Photosynthesis is arguably the most important biological process on earth

Photosynthesis is arguably the most important biological process on earth. All of our biological energy needs are met by the plant kingdom, either directly or through herbivorous animals. Plants in turn obtain the energy to synthesize foodstuff via photosynthesis. During photosynthesis, carbohydrates are formed. From carbohydrates, fats, proteins and other organic compounds are formed. Thus, all these food substances will eventually become the food of animals either directly or indirectly. Sunlight is the ultimate source of energy for living things. It is during photosynthesis that the radiant energy is converted to chemical energy, which is stored within the carbohydrate molecules. Hence, when animals feed on plants, they obtain this energy directly from them. Currently, there is a lot of discussion concerning the possible effects of carbon dioxide and other "greenhouse gases" on the environment. Photosynthesis helps to purify the air in the sense that it removes carbon dioxide from the air. In addition, it also helps counteract the effect of combustion of fossil fuels. The burning of fossil fuels releases not only carbon dioxide but also hydrocarbons, nitrogen dioxide and other trace materials that pollute the atmosphere and contribute to long-term health and environmental problems. As photosynthesis consumes carbon dioxide, it also produces oxygen. This oxygen is used

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  • Level: GCSE
  • Subject: Science
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Investigation into the factor of light and dark affecting woodlice.

Investigation into the factor of light and dark affecting woodlice Predictions It was expected that a woodlice would prefer a damp, dark, but moderately warm surrounding. Normally one would expect to find slaters under logs or concrete slabs in one's garden. Under these large objects, the sun cannot reach directly; therefore it is darker, damper and colder than the surroundings. Nevertheless, in winter we do not see woodlice crawling around very often, and, also at night, it may actually be warmer under such objects, because it looses heat more slowly, so I predict that the woodlice would prefer a dark, damp and a temperature of around 15oC. (The ground temperature of a typical Scottish day). This preference to dark and damp surroundings is mainly due to woodlouse's inefficient water-storage system. A woodlouse, if exposed to heat or light for too long, can die due to the dramatic loss of water. They prefer a moderate temperature, because they are so small, and can be damaged by frost if they are exposed to the extreme of cold, but they don't want such a high temperature, either, because they would start loosing too much water. I would also expect the woodlouse to prefer a surrounding of slightly higher pressure (1.05 ~ 1.1 atmosphere), because water evaporates more slowly under a high pressure. However, this is not investigated in this experiment due to the nature of the

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  • Level: GCSE
  • Subject: Science
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The effects of organic effluent from the seweage on the biodiversty in a freshwater stream.

AIM: The aim of this investigation is to find out the effects of organic effluent from the seweage on the biodiversty in a freshwater stream. This will be done by looking at biotic(such as food supply, competition and predation) and abiotic factors (such as oxygen concentration in water, light and nitrate levels in the water) neccessary for the servival of most sea organisms. Biotic index will be used to determine levels of organic effluent from the seweage in the fresh water stream and Diversty index will be obtained to see how diverse species are in a given area of the stream according to the levels of organic effluent present.The areas selected will be at random and they will be selected by considering all the health and safety measures when I reach the fresh water stream.This method will ensure that the results obtained are reliable. I will back up my results for the biotic index and the diversty index by carrying out BOD, light and nitrate levels test for the abiotic factors so that the biodiversty of selected areas can be explained by taking into consideration the various levels of organic effluent. BACKGROUND RESEARCH: Water is vital for the existance of life. The man uses water for various reasons. e.g. 1. Used for drinking and for domestical livestock. 2. Seweage is removed by water. 3. It is used to irrigate crops. 4. It has industrial uses e.g a coolant

  • Word count: 12801
  • Level: GCSE
  • Subject: Science
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Aral Sea Disaster The Aral Sea borders Uzbekistan and Kazakhstan and has two rivers running into it, the Amu Daria from

Aral Sea Disaster The Aral Sea borders Uzbekistan and Kazakhstan and has two rivers running into it, the Amu Daria from Uzbekistan and the Syr Daria from Kazakhstan. It used to be the fourth largest sea in the world but it has been shrinking and now, in some places, the shoreline lies 80km from where it used to be. The main cause for this is the government; they did not care about the environment, they just saw it as an obstacle to be beaten. Their only aim was to make as much profit as possible, the area around the Aral Sea was mainly desert and had no economy so was making no profit. The government came up with a plan to grow cotton and rice. They built a dam across the river to collect water into reservoirs to be used for irrigating the crops. Cotton and rice are very thirsty plants so they need a lot of water to grow, the farmers had no restrictions on how much water they could use and used a method called flood irrigation to water the crops which is not a very effective method as a lot of the water is lost, this meant that a lot of water was being used up and wasted. Also almost half of the water was lost or evaporated before it reaches the plant. Because of this the sea was not being supplied with enough water. Locals could sea that the Aral Sea was shrinking but they could not speak out as Uzbekistan and Kazakhstan used to be part of the Soviet Union which was

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  • Level: GCSE
  • Subject: Science
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To investigate the factors that affect the rate of photosynthesis.

Key Stage 4 Biology Coursework Aim: to investigate the factors that affect the rate of photosynthesis. Planning Photosynthesis equation: carbon dioxide + water sunlight glucose + oxygen 6CO2 6H2O chlorophyll C6H12O6 6O2 Photosynthesis is the process that produces 'food' in plants. The food it produces is glucose. Photosynthesis takes place in the leaves of green plants. Plants need light, carbon dioxide, water and chlorophyll in order to photosynthesise. The leaf is where the food is made. It gets light usually from the sun. The carbon dioxide enters the leaf form the air around. Water comes form the soil, up to the stem and into the leaf. The most important thing is the chlorophyll, which is found in the chloroplasts. The chlorophyll absorbs the energy from the sunlight and uses it to combine carbon dioxide and water to produce glucose. Oxygen is a waste product. Therefore these are all limiting factors. The rate of photosynthesis is affected by a number of factors including light levels, temperature, availability of water, and availability of nutrients. If the conditions that the plant needs are improved the rate of photosynthesis should increase. The maximum rate of photosynthesis will be constrained by a limiting factor. This factor will prevent the rate of photosynthesis from rising above a certain level even if other

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  • Level: GCSE
  • Subject: Science
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Investigation: Photosynthesis & Light Intensity

GCSE SCIENCE INVESTIGATION: PHOTOSYNTHESIS & LIGHT INTENSITY Aim: The aim of this experiment is to investigate how the intensity of light will affect the rate of photosynthesis in Kabambe (pondweed). To do this, Kabambe was placed in varying light intensities to test the amount of bubbles given off from a cut end to show the rate of photosynthesis occurring. Intro: Photosynthesis occurs only in the presence of light, and takes place in the chloroplasts of green plant cells. Photosynthesis can be defined as the production of simple sugars from carbon dioxide and water causing the release of sugar and oxygen. The chemical equation for photosynthesis can be expressed as: (light) 6CO2 + 6H2O = C6H12O6 + 6O2 (in the presence of chlorophyll). Now from most experiments involving photosynthesis it has been seen that without light, the plant or organism will most certainly die. This is to rule out one null hypothesis that without light, no photosynthesis will take place. Light intensity affects the rate of photosynthesis because firstly a change in value would directly change the balancing factor of the equation, as stated above, therefore raising a output of the equation, e.g. most light would need more carbon dioxide and water to increase the amounts of glucose and oxygen, without there will be a limiting factor to the amount of light that can be put into the input part of the

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  • Level: GCSE
  • Subject: Science
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An investigation to find out how temperature affects membrane permeability.

Philip Pearson AS Biology Practical Assessment An investigation to find out how temperature affects membrane permeability. Problem What we will hopefully try and find out in this investigation is if temperature affects the permeability of a beetroot membrane Hypothesis As the temperature in which the beetroot is put in increases there will be more red dye diffusing out of the beetroot due to the denaturing of the proteins in the cell membrane as a result of the high temperatures. Background Knowledge The cell membrane can be represented as the fluid mosaic model as shown below. It is selectively permeable and controls what enters and exits the cell. It does this by proteins, however small lipid molecules, non-polar molecules and small water molecules can enter and exit the cell straight across the membrane through the phospholipids, due to the properties of the molecules enabling them to do so. Extrinsic and intrinsic proteins in the cell membrane help other the molecules enter or leave the cell by either facilitated diffusion or active diffusion. Different proteins are specific to certain molecules hence the cell membrane being selectively permeable. Here is a diagram of the cell membrane: As you can see the cell membrane is made up of a phospholipid bilayer which the extrinsic and intrinsic proteins span through. Some of the extrinsic proteins act as antigens for

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  • Level: GCSE
  • Subject: Science
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