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GCSE: Green Plants as Organisms

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  • Marked by Teachers essays 56
  • Peer Reviewed essays 13
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  1. Marked by a teacher

    The roles water in living organisms and water as a habitat for organisms

    5 star(s)

    The diagram above shows the differing electronegativities, and it is for the polar nature of this molecule that water is such a good solvent. More substances than any other can dissolve in it, and it has been named the universal solvent. In plants, mineral salts can only be obtained when in solution, and water makes this possible. Likewise in humans, digestion only occurs when the food is in solution. The reactions of metabolism take place in solution, and also waste products are removed in solution.

    • Word count: 3301
  2. Marked by a teacher

    Investigating Factors Affecting the Rate of Photosynthesis.

    5 star(s)

    Hypothesis When chlorophyll absorbs light energy, the light energy cannot be immediately used for energy conversion. Instead the light energy is transferred to a special protein environment where energy conversion occurs. This happens by using the energy of a photon to transfer electrons from a chlorophyll pigment to the next. When enough light energy has been harnessed at a reaction centre, ATP can be synthesized from ADP. During this reaction, oxygen is produced as a by-product and it is the oxygen bubbles that are being measured in this experiment.

    • Word count: 3553
  3. Marked by a teacher

    Investigate the effect of huddling on heat loss.

    5 star(s)

    Thousands of penguins have been seen in the Antarctic nestling together. It is can be said that huddling together is the most vital adaptation of penguins to survive the breeding season, when the males are incubating the eggs and do not go out to find food, a source of energy. PLANNING B Independent variable: the size of the huddle Dependent variable: the amount of heat lost as a huddle Controlled variables: - the type of test tubes - thickness of the test tube glass - size of test tubes - the same test tubes were used - source of hot water - use of hot water, not any other substance -

    • Word count: 3442
  4. Marked by a teacher

    An investigation into the effect of light intensity on the rate of photosynthesis of Canadian pondweed (Elodea canadensis)

    5 star(s)

    Light intensity has a more immediate effect on the rate of photosynthesis than any other factor. In the dark, photosynthesis stops completely. Light, temperature and carbon dioxide not only affect the rate of photosynthesis but also limit how fast it goes. They are called limiting factors. For example, as the light intensity increases, so does the rate of photosynthesis. But then it reaches a maximum rate which when the light intensity increases; there is no more affect of the rate of photosynthesis. Now carbon dioxide concentration or temperature may become the limiting factor. (This picture is from: www.marietta.edu/~spilatrs/biol103/photolab/photosyn.html)

    • Word count: 4399
  5. Marked by a teacher

    Year 11 Module B4 Revision notes. Plants, photosythesis, biomass and the carbon cycle.

    4 star(s)

    The water molecules can pass through both ways ? they move randomly all the time. Because there are more water molecules on one side than the other, there is a steady net flow of water into the region with fewer water molecules, i.e. water moves into the stronger sucrose solution. This means the concentrated sucrose solution gets more dilute. Turgor pressure ? supports plant tissues When a plant is well watered, all its cells will draw water in by osmosis, they become plump and swollen. When cells are like this they are said to be turgid.

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  6. Marked by a teacher


    4 star(s)

    Brook trout have strong, streamlined bodies and powerful tail fins that can push against the current. These fish need the cold, oxygen-rich water of a flowing stream in order to thrive. Shade is very important in keeping the stream cold. Atlantic salmon are famous for their ability to buck the current. They swim upstream in spring in order to lay their eggs on the gravel bottom where they were born. Where man-made dams block their route, they will dash themselves to death against the concrete walls trying to leap over them. Other animals adapt to the swift current.

    • Word count: 6559
  7. Marked by a teacher

    An investigation into the abundance of fresh water black fly larvae, Simuliidae, between pools and riffles in Woodford meanders on the 19th September 2003.

    4 star(s)

    Without the action of detritivores to increase the surface area of this particulate matter, the rate of decomposition is reduced, or stops altogether. The gradual reduction in particle size is often called comminution. Excerpted from The Oxford Interactive Encyclopedia. The black fly larvae, Simuliidae, spins a small silken mat over a surface of the stone and then using it's posterior hook circlet, it positions itself on the silken mat so that the body is projected down stream parallel to the current.

    • Word count: 6634
  8. Marked by a teacher

    Light Intensity and Photosynthesis.

    4 star(s)

    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 the other conditions needed for photosynthesis are improved. It will therefore be necessary to control these factors throughout the experiment so as not to let them affect the integrity of my investigation into the effect of light intensity. Predictions I predicted that as the intensity of light increased, so would the rate of photosynthesis. Furthermore, I hypothesised that if the light intensity increases, the rate of photosynthesis will increase at a proportional rate until a certain level is reached, and the rate of increase will then go down.

    • Word count: 3032
  9. Marked by a teacher

    Investigation to find out how light intensity effects the rate of photosynthesis

    4 star(s)

    But carbon dioxide is continually added to air by respiration of all living organisms and by burning of fuel such as wood, coal, gas, oil and petrol all give off carbon dioxide when they burn. There is no danger that carbon dioxide will run out in fact it is slowly increasing in the air because so much burning takes place. Carbon dioxide dissolves in water, which can release carbon dioxide: flowering living plants living in water therefore also have a supply of carbon dioxide.

    • Word count: 3299
  10. Marked by a teacher

    An investigation into the effect of a germination inhibitor on the germination of seeds.

    3 star(s)

    This is similar to the water-soluble protein germination inhibitor found in tomatoes because this will also alter the rate of reaction; it will alter the rate of germination in the seeds. Enzymes can be denatured when the temperature rises above their specific optimum temperature because the molecules vibrate so much that the bonds break and so the structure and shape is changed. So this germination inhibitor will have an optimum temperature and, like enzymes, will stop working to its particular function when this temperature is exceeded.

    • Word count: 6990
  11. Marked by a teacher

    Factors That Affect the Rate of Photosynthesis

    3 star(s)

    Changing it to more or less can affect our experiment because the amount of chlorophyll changes the rate either faster or slower depending on how much you are using. Using more can help speed up the rate as there are more chlorophyll, using less can slow the rate as there are less chlorophyll to help photosynthesize. Therefore, when we change the plant, the amount of chlorophyll will also change. -Type of Plant: We need to control that we use the same type of plant throughout the whole experiment.

    • Word count: 4538
  12. Peer reviewed

    An Investigation into the Effects that Different Light Intensities have on the Speed of Woodlice:

    5 star(s)

    Thus there will be a positive correlation between light intensity and the speed of movement. My Ho hypothesis is that there will be no significant correlation found between light intensity and the speed of movement. Consequently, I will use the Spearman's rank correlation coefficient statistical test or the Product Moment correlation coefficient, depending on the distribution of my data, in order to test this hypothesis. The distance values that I will use for my experiment, which will alter the light intensity, will be 10cm, 20cm, 30cm, 40cm, 50cm, 60cm, 70cm, 80cm, 90cm and 100cm as this will enable me to

    • Word count: 6388
  13. Free essay

    Investigation osmosis in potato cells

    In my experiment, there may be a concentration of the solution which has an equal water potential to the potato, which will result in neither a gain nor a loss of mass for the potato chip as the water would have no preference of location. Plant vacuoles accumulate enough dissolved compounds to give the plant cell a low enough osmotic potential to absorb water via osmosis. Preliminary test: List of apparatus: List of Apparatus Why chosen and how used Beaker Holds the sucrose solution in.

    • Word count: 3173
  14. What effect does the sucrose concentration have on osmosis?

    This liquid or hydrostatic pressure works against osmosis. Turgidity is very important to plants because this is what makes the green parts of the plant keep upright and it gives non-woody plant cells support in the sunlight. Since potatoes are plants the same thing will happen to its cells - they will expand and become more turgid. If a plant cell is placed in a concentrated sugar solution it will lose water through osmosis and become "flaccid"; this is the exact opposite of "turgid". If, then you put the plant cell into a concentrated sugar solution and look at it under a microscope you would see that the contents of the cells have shrunk and pulled away from the cell wall: they are said to be plasmolysed.

    • Word count: 3946
  15. Experiment to investigate the effect of Carbon Dioxide on the Rate of Photosynthesis

    Figure 1 shows the structure of the stomata. Adjacent to the pore (stoma), are two guard cells. Changes in turgidity of these guard cells causes them to change shape so they are either open or closed. Thus the number of stomata present will affect the amount of carbon dioxide available to the leaf. Another important consideration is the utilisation of carbon dioxide. Carbon dioxide enters into the stroma of the chloroplast and becomes part of a cycle of events known as the Calvin cycle, the outcome of which is glucose a 6-Carbon sugar.

    • Word count: 3045
  16. Investigating the effect of temperature on the rate of photosynthesis

    Aim: The aim of this experiment is to evaluate the effect of varying the temperature on the rate of photosynthesis. This will be done by measuring the rate of oxygen released from the olodea. Introduction: In my experiment I will be measuring the volume of oxygen released from the elodea by shining a lamp to give the elodea light energy needed for photosynthesis to occur. I will repeat the experiment with the elodea in different temperatures to see the affect of this on photosynthesis. From the volume of oxygen released we will use this to predict the rate of photosynthesis.

    • Word count: 9028
  17. How temperature affects the rate of photosynthesis.

    Temperature was the only factor to be varied, which meant that the other two limiting actors had to be available constantly and in plenty. Excess carbon dioxide was provided by adding equal amounts of sodium hydrogen bicarbonate to each test tube which dissolved in water to provide carbon dioxide and the light intensity was controlled by providing only one artificial source of light i.e. a lamp which was kept at the same distance of 50mm from each test tube (with the elodea in it).

    • Word count: 20228
  18. Free essay

    Solar Desalination Plant

    Having proven itself as a cost effective and environmentally friendly design, the Desalinator's solar desalination plant solution is the best and only solution to recover from Victoria's drought and increasing water supply demand. NX-Drawing of a Solar Desalination Water tank 1. INTRODUCTION This Project Brief calls for submissions to design, develop, and finally build the first-ever Desalination Plant in Victoria in accordance with the assertion of ideas that appends this brief. The installation of the new desalination plant will be primarily a focal point of significance, with various new technologies adopted to ensure it is a sustainable development.

    • Word count: 3794
  19. An investigation into the effects of different concentrations of lead chloride on the growth of plants, (cress).

    For lead to be transported from the soil to the root cells, it must cross the cell membranes of the root cells. Lead is able to cross the cell membranes via voltage-gated calcium channels. These channels are for the transport of calcium. Lead blocks these channels and causes the inhibition of their activity, preventing calcium being transported. For photosynthesis to occur plants require water. When lead is present in high concentrations in soil, it decreases the water potential of the soil.

    • Word count: 5975
  20. This experiment involves using a photosynthometer to investigate how temperature affects the rate of photosynthesis in the elodea.

    Having said this, research had also stressed that temperature can have a significant impact on the rate of photosynthesis. Thus a firm conclusion can be made that photosynthesis compromises two processes known as the 'light dependant photochemical stage' & the 'light-independent temperature dependant stage'. From this we can see that light independent stages are primarily influenced by temperature. In the chloroplast lamellae, light is trapped by pigments which can either be Chlorophyll's (a and b) or Carotenoids (B carotene and xanthophyll). Different pigments absorb different wavelength of light. An absorption spectrum for a particular pigment describes the wavelengths at which it can absorb light.

    • Word count: 5237
  21. Mangrove Soil Analysis

    Prediction: I predict that the soil with the highest percentage of sand will be the Trinity Beach sample. The soil with the highest percentage of clay will be the Clay sample. The soil with the highest percentage of silt will be the Outer Zone Mangrove Sample. Materials: * 6 x 200mL measuring cylinders * 3 x Mud samples from different areas of the mangroves (Inner, Middle and Outer Zones) * Ruler with mm measurements * Disposable Gloves * 3 x Samples of various areas (Beach, Rainforest and Clay Soil) * Spoons * Sieve Diagram: (For Step 4 and 5)

    • Word count: 5495

    as using any higher or lower may take up to much time in getting to the required temperature. expect the graph for the results to look as follows:: increasing the temperature will cause the partially permeable membrane of the Beetroot to become damaged and so it will be less rigid. Also I predict that after 40C the proteins in the cell membrane will start to denature as they will reach the optimum temperature. This will increase the permeability allowing more colour to be released.

    • Word count: 6278
  23. The relationship between flow rate and temperature difference

    Thus, water is "thin", having a lower viscosity, while vegetable oil is "thick" having a higher viscosity. All real fluids (except superfluids) have some resistance to shear stress, but a fluid which has no resistance to shear stress is known as an ideal fluid. Viscosities of all liquids are strongly temperature dependent, increasing for gases and decreasing for liquids as the temperature increases. The SI physical unit of dynamic viscosity (Greek symbol: �) is the pascal-second (Pa�s), which is identical to 1 kg�m-1�s-1.It has been found that the relationship between viscosity and the flow rate of a liquid is directly proportional.

    • Word count: 3193
  24. catalase and hydrgen peroxide

    I connected the other end of to the rubber tubing to the side arm tube. I then added about 15cm� of hydrogen peroxide into the side arm tube with the potatoes and closed it by placing a rubber bung on top. This allowed the reaction to occur which produced oxygen and sent it up through the tube in bubbles. I left this for 5 minutes, and counted the amount of bubbles produced every minute by using the stop clock. I took down these results and recorded them in a table, so that they are easier to read and understand.

    • Word count: 7272
  25. The aim of my investigation was to determine how limiting factors would affect the rate of photosynthesis in a plant.

    The hydrophobic tail is made up of carbon, hydrogen and oxygen based molecules. The 'head' of a chlorophyll molecule is ring called porphyrin. The porphyrin ring of chlorophyll, which has a magnesium atom at its center, is the part of a chlorophyll membrane that absorbs light energy. This energy is used to make carbon dioxide react with water to make glucose. Chlorophyll is found in chloroplasts which are double membrane bound organelles which enclose additional membranes called thylakoids. The disc shaped thylakoids posses an interior space. The thylakoids are stacked to form grana, which are suspended in the stroma of the chloroplasts.

    • Word count: 6116

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