GCSE: Green Plants as Organisms

Meet the team of inpirational teachers who mark our essays

find out about the team

Join Marked by Teachers to get help from over 80 teachers and 180,000 essays

1,127 GCSE Green Plants as Organisms essays

  • Marked by Teachers essays 56
  • Peer Reviewed essays 13
  1. 1
  2. 2
  3. 3
  4. 4
  5. 46
  1. Marked by a teacher

    Biology lab - transpiration

    5 star(s)

    Pressure begins to build in the leaves, so to prevent downward movement, guttation occurs. Guttation occurs through leaf openings on the leaf margins called hydrathodes. Loss of water through transpiration can be facilitated by the opening and closing of the stomata depending on environmental conditions. There are three types of cells in plants: parenchyma, sclerenchyma, and collenchyma. Parenchyma cells are the most abundant and are not specialized. They are found in the mesophyll of leaves, the flesh of fruits, the pith of stems, and the root and stem cortex.

    • Essay length: 1729 words
  2. Marked by a teacher

    Biology CourseworkTo determine if the distribution of flora across Ellerbeck is due to chance. The valley containing Eller beck possesses a huge variety of different species of plant life, particular species are often found in specific places

    5 star(s)

    I also plan to perform an interrupted belt transect along the same bearing. Laying down a quadrat frame on the left side of my tape measure at regular intervals of 10 metres and recording in detail, the distribution of species within the frame. This will give me a general view of the distribution of different species in many areas across the valley allowing me to sample the abundance and frequency of the different species, providing quantitative data and will allow me hopefully to speculate on the distribution of those species in the whole area.

    • Essay length: 2444 words
  3. Marked by a teacher

    The effects of shade from trees on plants below

    5 star(s)

    A woodland habitat Within a woodland habitat the main dominating organisms are the trees. The reason for their domination apart from the fact that they are usually larger than most other wildlife is due to the fact that trees have large canopies of branches and leaves. The canopies are situated at the top of the trees therefore casting a shade on all that grows below it. Woods are described as Strasfied; this is because woodland areas are in layers and block out most of the light. Layer Description Canopy layer Ash, Oak, Elm, Cherry, Sycamore Shrub Layer Small trees growing under the canopy layer e.g.

    • Essay length: 2231 words
  4. 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.

    • Essay length: 3301 words
  5. 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.

    • Essay length: 3553 words
  6. Marked by a teacher

    How the molar concentration of NaHCO3 (Sodium Hydrogen Carbonate) affects the rate of photosynthesis in Elodea.

    5 star(s)

    I will vary this variable so that I can discover if there is a proportional relationship between this and the amount of oxygen produced as a result of photosynthesis. Light intensity:- if the light intensity is increased, the number of bubbles produced by the Elodea will also increase which is why I have to make sure that it remains constant, so as to produce more accurate results. I will make sure that the lamp remains at the same distance from the Elodea by marking its position with a pencil.

    • Essay length: 2028 words
  7. 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 -

    • Essay length: 3442 words
  8. 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)

    • Essay length: 4399 words
  9. 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 â 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 â 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.

    • Essay length: 4222 words
  10. Marked by a teacher

    Biology Lab Report. Does light intensity affect the rate of photosynthesis?

    4 star(s)

    Apparatus: 7 boiling tubes, 7 rubber stopper, 1 black paper, capillary tube, lamp Materials: Pond weed, fresh sodium bicarbonate indicator Method: 1. CO2 was blown into some fresh bicarbonate indicator until it turns to red, which used for experiment. 2. The test tubes are set up like in the diagram 1 and placed at varying distances from the light source. For the control experiment, put in a dark place with no light. 3. The time taken for bicarbonate indicator in each test tube to turn from deep red to purple is taken and recorded.

    • Essay length: 652 words
  11. Marked by a teacher

    AN INVESTIGATION OF THE DIFFERENT SPECIES OF MAYFLY WITHIN THE POOL & RIFFLE

    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.

    • Essay length: 6559 words
  12. Marked by a teacher

    investigate the effect of carbon dioxide concentration on the rate of photosynthesis.

    4 star(s)

    Plants need light energy in order to make food. The more light they have the faster they can make food. Again there is a limit. Making the light very bright will not make the plant photosynthesise any faster as the plant is making food as it can. * Temperature - this can be done by simply heating the water to different temperatures. When it is cold the plant makes food slowly. This is because the chemical reactions which drive photosynthesis are very slow.

    • Essay length: 1106 words
  13. Marked by a teacher

    "The Importance of Water to living Organisms"

    4 star(s)

    Between 0 and 100°C and at atmospheric pressure water is a liquid. Due to the position of earth in relation to the sun most of the water on the planets surface exists in a liquid state, on other planets such as Venus and Mars water exists as a gas and a solid making it impossible for life to exist. Water readily dissolves a wide range of inorganic and organic molecules, creating what is known as a solution. All chemical reactions within living cells take place in aqueous solution.

    • Essay length: 1564 words
  14. Marked by a teacher

    The Biological Importance of Water.

    4 star(s)

    Water does not only keep us to live and present, but it also helps very much in our life, and it is actually a very interesting substance to have a research about. Water is a liquid at room temperature; water dissolves more substances than any other common liquid. We can use it to take a closer look for biochemistry of life. Evaporation of water requires a great deal of heat. Which means that much heat is lost by evaporation of a small quantity of water.

    • Essay length: 2173 words
  15. Marked by a teacher

    Biology investigation to investigate how selected variable affects the rate of fermentation in yeast.

    4 star(s)

    After about 70°C all of the enzymes will have become denatured and none will work. There is just one variable in this experiment. I will change the temperature. The range of values that I have chosen is as follows: 25°C 35°C 40°C 55°C 70°C It is important that I keep constant all other factors so that the experiment is a fair test. I will keep the same: * The volume of the yeast suspension (50cm³) * 2g of yeast in 50cm³ of water (4%)

    • Essay length: 1356 words
  16. Marked by a teacher

    The Effect of Carbon Dioxide Concentration On The Rate of Photosynthesis.

    4 star(s)

    * Different conditions (temperature) * Amount of pond weed We are going to change the sodium hydrogen carbonate solution concentration/molar to look at the effect the amount of carbon dioxide has on the rate of photosynthesis. Everything else will be kept the same. Safety Be careful when handling glass and allow the lamp to cool before packing it away or touching. Keep the area your working in clean and tidy; clean up any spillages. Apparatus * Lamp * Beaker * Test tube * Measuring cylinder * Pond weed * Sodium hydrogen carbonate (variety of molars)

    • Essay length: 1073 words
  17. 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.

    • Essay length: 6634 words
  18. Marked by a teacher

    Use of a redox indicator to show dehydrogenase activity.

    4 star(s)

    Leave for several minutes to reach the temperature of the water bath. 3. Mix the yeast suspension and TTC solution together and return the test tube to the water bath. Start the stopwatch immediately. 4. Observe carefully and note the time taken for any colour changes to develop. 5. Repeat this procedure at a range of suitable temperatures, for example 20?C, 40?C and 50?C. Results and discussion: The yeast suspension and TTC solution were placed in the water bath before mixing together because the contents of both test tubes need to be at the same temperature as the water bath.

    • Essay length: 968 words
  19. Marked by a teacher

    Core practical - Why does the colour leak out of cooked beetroot? Investigating the effect of temperature on a beetroot cell membrane.

    4 star(s)

    As we are experimenting with the effects of temperature on the membrane, we will place the samples of beetroot into a water baths of varying temperatures and measure the colour change in the water. Temperature is just one of the possible variables. The dependant variable in this experiment is colour change in water caused by anthocyanin leakage. This will be recorded using a colorimeter and the results can be expressed in units of parts per million (ppm), milligrams per liter (mg/l), grains per gallon (gpg)

    • Essay length: 1453 words
  20. Marked by a teacher

    How does temperature affect the permeability of a cell membrane in a beetroot.

    4 star(s)

    Temperature also causes the lipids of the membrane to be more fluid. It also causes the proteins to denature. However as the proteins denature and the lipids become liquid like, bigger gaps emerge so larger molecules can diffuse more freely. As the proteins denature the protein channels will increase in size so that more hydrophilic molecules can diffuse through in a shorter space of time. Surface area of beetroot: The surface area of the beetroot is to be the same for each of the segments. The diagram below shows the shape of the segments: 1 2 Cylinder Surface area is worked out using the following formula: Area of end 1 + Area of end 2 + area of sides (cylinder shape)

    • Essay length: 2745 words
  21. Marked by a teacher

    Human Influences On the Environment.

    4 star(s)

    As forests are destroyed in this way, habitiats are removed from the animals living in them, therefore the biodiversity decreases. Forests also hold a big role in the water cycle as they release back the water that falls on them through transpiration. If trees are removed this may reduce the amount of water vapour that returns to the air, and may reduce rainfall either locally or in nearby regions which could inevitibly lead to drought. Trees also intercept the rain , lack of interception means that the water will not be slowed down on its journey to the ground.

    • Essay length: 656 words
  22. 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.

    • Essay length: 3032 words
  23. Marked by a teacher

    Effect of different substrates on fermentation by Yeast.

    4 star(s)

    We do not know what yeast can do, we know that it can break down glucose, but we do not know if it can break down starch into glucose to release carbon dioxide. So this experiment should help me to see what yeast can do. Plan: Collect and set the apparatus up as shown in the diagram. Heat the water to 40°C. Weigh out 1g of yeast, 2g of substrate and 3ml of water, and put in the test tube.

    • Essay length: 775 words
  24. Marked by a teacher

    An experiment to show how water loss in leaves can vary.

    4 star(s)

    some leaves are fleshier than others. * The petiole sizes can be different and the bigger the petiole, the bigger the water capacity the leaf can hold. * Varying amounts of Vaseline means that some leaves have differing strengths of barriers preventing them from transpiring, also un even distribution of the Vaseline could result in some of the stomata being uncovered compared to others that do not. * Drying the leaf is quite important because if you did it unequally, the leaf could absorb this so it has a greater water supply before the investigation has even started.

    • Essay length: 1274 words
  25. Marked by a teacher

    To investigate the factors which affect the rate of cooling of a hot object.

    4 star(s)

    I will repeat the experiment three times for each volume of water starting from 50ml. Fair test I will do all the experiments on the same day so that the weather conditions and surrounding temperature are the same for all of my results. This is because on another day the weather conditions would be different and would effect the surrounding temperature and therefore effect the rate the water in my experiment cooled. I will use the same measuring cylinder for all my experiments because another cylinder would measure the required amount slightly different, as they are all slightly different.

    • Essay length: 957 words

Marked by a teacher

This essay has been marked by one of our great teachers. You can read the full teachers notes when you download the essay.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the essay page.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review under the essay preview on this page.