How the concentration of salt-water affects the rate of osmosis.

How the concentration of salt-water affects the rate of osmosis. Aim: To find out how the concentration of salt-water affects the rate of osmosis in a potato. Prediction: My prediction is when the concentration of salt-water gets higher the mass of the potato will get smaller. The reason for this is because when the concentration of salt is low the concentration of water will be high. The water moves from a high concentration to a low concentration. The potato has a low concentration of water so the water passes through the semi permeable membrane and the potato gains water through osmosis, increasing the mass of the potato. If the concentration of salt is high then the concentration of water will be low. The water passes from high concentration to a lower concentration so if the concentration of water outside the potato is lower than inside the water passes out of the potato reducing the mass of the potato. Method: Variables: The variables that could affect the results are: * The time the potato is exposed to the water because the experiment may not be left long enough to show any affect. * The volume of salt-water will affect the potato because there is more water and sugar and so more water will want to move making the test unfair. * The size of the potato because if they are different sizes the potato may gain more water because it can hold more making the

  • Word count: 556
  • Level: GCSE
  • Subject: Science
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Human activities pollute air, water and land in different ways.

By Arran Roberts Contents Page Title 2 ..........................................................Contents 3..........................................................Loss Of Habitat 5...........................................................Human Activities 7............................................................Solutions Loss of Habitat The amount of land available for animals and plants is reduced by Man's land use, mainly activities such as quarrying, building, farming and dumping waste. Quarrying is a major threat to plants which grow specifically in rocky areas, such as yellow larkspur and American Hart's-Tongue Fern. Plants of this nature are becoming more difficult to find as more quarries appear. (Lakeside daisy threatened by limestone quarrying) Building is a large cause of loss of habitat, towns and cities are outwardly expanding and more land is being used for housing and other large scale building projects such as shopping malls and new roads. Draining of swamps and wetlands and deforestation are also greatly contributed to by building. Loss of habitat and habitat fragmentation are areas of major concern in species conservation, building often results in large areas of habitat being broken up into a series of smaller areas, each of which will support fewer species. (Building site) Farming and agriculture reduce amounts of

  • Word count: 888
  • Level: GCSE
  • Subject: Science
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Does the Concentration of CuSO4 Affect the Germination of Barley Seeds?

Does the Concentration of CuSO4 Affect the Germination of Barley Seeds? Investigation Analysis When looking at the data collection sheet it can be seen that as the concentration of CuSO4 increases, the percentage of seed germination decreases. This already shows a clear sign that enzyme inhibition has occurred. Looking at the "Average Length of Roots" graph, it can be seen that the concentration of CuSO4 does inhibit the growth of roots significantly because the average root length drops sharply after the 0% solution. However some of my results nay have been anomalous because the decline is far too steep to draw any reliable conclusions. When comparing this graph to the "Average Length of Shoot" graph, it can be seen that the average shoot length for each concentration depreciates at a steadier rate; perhaps then, heavy metal ions affect enzymes that are responsible for root growth more than they affect those that are responsible for shoot growth. This is could be a topic for further investigation. For both graphs however, its shows that the depreciation rate between each concentration decreases. For example, using the "Average Length of Roots" graph it can be seen that the gradient between each concentration becomes steadier and steadier as the concentration increases. This shows that inhibition of growth is affected most directly after the 0% concentration. When

  • Word count: 836
  • Level: GCSE
  • Subject: Science
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The Gower Peninsula

Biology Coursework Field Studies The Gower Peninsula Introduction Before deciding on what to do for my main investigation, I decided to carry out a preliminary investigation on two different beaches. One was sheltered and one was an exposed beach. This preliminary investigation will give me some knowledge of the variety of species on the beaches from which I will choose one to concentrate on in my main field study. I chose a site close to Mumbles, which is near Swansea in Wales as the site for the investigation because there is a sheltered and an exposed beach very close to one another in that area. One is exposed to the powerful waves of the Atlantic Ocean while the other is sheltered by a bay. I will also observe the changes in species abundances to give me an idea of where the different zones on the beaches are and so help me further with choosing my main investigation. Preliminary Investigation I will be using a transect technique to record my data, this way the investigation could be repeated easily as the method is simple and allows for a margin of error. There are three types of transect but I have decided to use a belt transect for the following reasons. A line transect involves recording data along the whole length of the beach, from upper shore to lower shore, which is impractical given our time limit of between five and ten hours to record our data. A point

  • Word count: 2184
  • Level: GCSE
  • Subject: Science
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How Exercise affects heart rate

How Exercise affects heart rate Aim My aim is to find out how exercise affects heart rate, I am going to find this out by doing Sit ups and taking my pulse and seeing how much it increases / decreases as I do sit ups for a longer amount of time. To get a good pulse I am going to take my pulse over 15 secs and times it by 4 this will give me a closer pulse than waiting for a minute because it would then increase / decrease as I measured it. Safety I am going to make this experiment safe by: . Warming up and down 2. Not over doing my self 3. Taking a rest after each time of sit ups 4. Not doing sit ups near a wall or table. Factors The factors that will affect my experiment are: > The speed I do sit ups > Fitness > Temperature Fair Test I am going to make this a fair test by; > keeping to the same pace of sit ups during the timing, > resting till my pulse has returned to normal > do repeats > use the same person > use the same exercise Apparatus The equipment I will need is: . A stopwatch 2. Gym clothes 3. Test subject Method . Take your resting pulse 2. Start doing sit ups for 1 min and take your pulse 3. Do two more repeats 4. After your pulse has slowed do the same procedure but for 2 min. 5. Do the same for 3 + 4 min 6. Plot a graph Prediction As the time I do exercise for increases my pulse will also increase, this because as the

  • Word count: 747
  • Level: GCSE
  • Subject: Science
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Attack of the Clones - Is it right or wrong?

Attack of the Clones Is it right or wrong? Cloning is the creation of a human being, or a number of human beings, who are genetically identical to another. There are two types of cloning: therapeutic cloning and reproductive cloning. Therapeutic cloning is when cloning techniques are used to start the growth of embryos in order to create new organs or cells for medical purposes. The Government already allows scientists to carry out a certain amount of therapeutic cloning as it can help different patients in many ways. Through therapeutic cloning, livers would be able to be cloned for liver transplants, kidneys could be cloned for kidney transplants, bone marrow would be able to be cloned for adults and children who suffer from leukaemia and scientists are confident that they will be able to grow nerves or the spinal cord back again when people are injured. This would mean that quadriplegics such as the actor, Christopher Reeves would be able to get up and walk again. Reproductive cloning is the creation of a new person with the same genetic make-up as someone who is alive or has lived. Reproductive cloning would help people with some genetic diseases such as some heart conditions to have children of their own genetic offspring without taking the risk of passing on the disease to their children. This means that eventually, some diseases would be eradicated. Reproductive

  • Word count: 1005
  • Level: GCSE
  • Subject: Science
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Transpiration Coursework

Transpiration Coursework -Planning I plan on conducting an experiment to find out whether the surface area and number of leaves on an individual stem has any effect on the change of weight of the leaves. Hypothesis- I predict that the leaves will all become lighter, and the more leaves on the stem, the more weight will be lost. I predict this because the water is taken back into the leaves, and is lost through the tiny holes in the leaves called stomata. The stems with more leaves on them will lose more weight, as there are more holes for the water to be lost through, also, the leave with the largest surface area will lose the most weight for the same reason. Apparatus- Test- tubes Privet bush cuttings Beaker Balance Scales Water- 15 ml Oil Measurements- I will use a balance to measure the new weight of each test- tube. I will measure the specific amount of water being poured into each test-tube, and I will measure the surface area of an average sized leaf on each stem. I will do this by drawing round the leaf on squared paper, and then counting the squares. The weight will me weighed in grams (g), the surface area will be measured in cm squares, and the weight lost will be in grams (g). Fair Test- I will make this a fair test by; keeping the amount of water at a constant amount of 15ml, with 3 drops of oil on top so that the water does not directly

  • Word count: 1171
  • Level: GCSE
  • Subject: Science
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An experiment to show the progress of osmosis in potato tissues.

An experiment to show the progress of osmosis in potato tissues. Aim The aim of this coursework is to investigate the rate of osmosis in different concentrations of sugar solution using potato tissues. Prediction I think that in sugar solutions of high concentration, the mass of the potato will go down. This is due to the rules of Osmosis. Osmosis is the movement of water molecules across a partially permeable membrane, from a region of high water concentration to a region of low water concentration. There are two types of diffusion. These are: * Partially permeable membrane. This allows SOME particles to diffuse through things and not others. Most cell membranes are permeable to water. Diffusion of water through a partially permeable is 'The direction and rate of osmosis which depends on the differences in water concentration between the two sides of the membrane until equilibrium'. Only water molecules are small enough 2 diffuse through a partially permeable membrane. The tendency for water to move through a partially permeable membrane is described as its water potential and is at a maximum in pure water, if sugar is added to the solution, it lowers the water potential. The water potential depends on how much sugar solution is added. In high concentrations of water, the amount of sugar is low and in low concentrations of water, the amount of sugar is high. As the

  • Word count: 3591
  • Level: GCSE
  • Subject: Science
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How does Smoking Affect how Quickly Someone Recovers from Exercise?

How does Smoking Affect how Quickly Someone Recovers from Exercise? Preliminary Work . Count how many beats your heart makes in one minute [this is your resting pulse]. (A) 2.Exercise for one minute and record the pulse immediately. Again for 1 minute. (B) 3. Rest for 5 minutes and record the pulse again. (C) Beats per minute (A) Resting pulse 58 (B) After exercise 12 (C) After rest 58 Plan Many factors affect how quickly someone recovers after exercise. * Asthma. This is a disease, which makes the bronchioles narrower and so makes exchanging gases more difficult. * Bodybuilding. This adds on body mass, therefore making it harder to do exercise. * Smoking. This weakens the lungs by clogging it up with tar, which also makes it harder to breathe. * Drugs. There are many sorts of drugs, and they affect your body in many different ways. * Alcohol. This all depends on the amount of alcohol you take in. * Food. If you are overweight, you should go on a diet, but if you have yourself a poor diet you will start to gain weight. This is because of the lack of nutrients. The variable in which I have chosen is ... Smoking. Apparatus Here is the list of apparatus that I will be using to perform my investigation... * Steps * Stop clock * Skipping rope * A person who smokes * A person who doesn't smoke How to measure the pulse First of all you should find out

  • Word count: 1397
  • Level: GCSE
  • Subject: Science
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Deserts, the water issue.

Desert, term applied to regions on the earth that are characterised by less than about 250mm of annual rainfall, and, in many cases an evaporation rate that exceeds precipitation, and a high average temperature. Because of the lack of moisture in the soil and the low humidity in the atmosphere, most of the sunlight penetrates to the ground. Daytime temperatures have reached 57.8 Degrees Celsius on the 13th of September 1922, this was the highest ever recorded in Libya. On the other hand at night the temperature can drop to near freezing. Deserts are found in ever continent throughout the globe from Africa to the cold plains of Northern China. Hot deserts extend all around the world in two belts, to the north and south of the tropical zone around the world's equator. Further from the equator, north and south are the cold deserts, and even further are the ice-covered polar deserts. Some deserts receive almost no rainfall, for example in southern Egypt, there are many years when rainfall is at an absolute zero. However when it does rain the downpour can be torrential. Thunderstorms quickly dampen the soil surface, then further water runs off the wet surface, creating flash-floods. 250 people passed-away from floods in Morocco in 1997, in the Atlas Mountains. Desert areas in some continents have formed because the "Prevailing winds", are far removed from areas of water and

  • Word count: 1552
  • Level: GCSE
  • Subject: Science
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