Investigate the movement of water into and out of plant cells by osmosis.

GCSE Coursework The aim of this experiment is to investigate the movement of water into and out of plant cells by osmosis. The cells chosen for study will be taken from potato tubers as they provide a ready supply of uniform material. Any substance dissolved in water is called a solute; a solvent is a liquid that is able to dissolve another substance, called a solute, to form a solution. The water content of plants varies depending on environmental conditions. In Land plants this water plays a vital role in the support of tissues and the transport of materials around the organism. Lack of water leads to wilting and eventually death. Water is mainly absorbed through the roots which are covered in specially adapted root hair cells, with large surface areas and thin cell walls to aid absorption. It is drawn up the plant through xylem vessels by a pull resulting from the evaporation of water through the stomata on the leaves. This evaporation is called transpiration and the xylem flow resulting is called the transpiration stream. Soluble food substances formed during photosynthesis are transported around the plant in the phloem tubes. This movement of water through the plant in the xylem vessels or phloem tubes is similar to the flow of blood in humans as it transports soluble mineral salts, nutrients and auxins, (plant hormones), from place to place. The evaporation of

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  • Level: GCSE
  • Subject: Science
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Practical: the effect of caffeine on heart rate.

Practical: the effect of caffeine on heart rate. In order to investigate the effect of caffeine on the heart rate, we used a tiny multicellular freshwater crustacean which is widely used for biological research. The daphnia species have a transparent body and a projecting head. They entail a pair of pronged antennae used primarily for swimming while also entailing a single compound eye. A daphnia has a divide of the head which lies between the head and the abdomen and five pairs of these form an efficient filter-feeding mechanism. Caffeine is a bitter alkaloid used in coffee that is responsible for their stimulating effects. Caffeine binds to receptors on the surface of heart muscle cells which leads to a faster heartbeat. Considering the effect caffeine has on humans, it is likely that the effect will be similar. It stimulates our heart to beat faster, so I predict that the effect on daphnia will most likely be the same if not more prominent in Daphnia die to their large surface area to mass ratio. I can predict that the heart rate will also increase, similar to a human and furthermore, the increase will probably be steeper when shown in a graph due to the miniscule size of a daphnia. Overall, I believe that a daphnia subjected to caffeine will show a rise in heart rate. The more caffeine in the solution should reflect the concentration in heart beat. To carry

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  • Level: GCSE
  • Subject: Science
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To plan a fair investigation that will show how abiotic factors such as water content of soil and soil pH effects the distribution and abundance of Ranunculus Repens and Ranunculus Bulbosus.

Apparatus and Materials x quadrat Ball of string 2 x pegs x hammer Key sheet to aid identification of species, e.g. Ranunculus Repens looks like this: It has creeping runners and grows low to the ground Ranunculus Bulbosus looks like this: It has sepals beneath the petals that are bent back and a ridged stalk with a bloated stem 0 x small pots and corresponding caps 0 x spoons Paper Pen x sieve x measuring cylinder x weighing scales 0 x petri dishes Oven gloves 0 x test tubes Water 0 x pieces of litmus paper Paper Pen Aim To plan a fair investigation that will show how abiotic factors such as water content of soil and soil pH effects the distribution and abundance of Ranunculus Repens and Ranunculus Bulbosus. Prediction I predict that more Ranunculus Repens plants will be found nearer the river because it is wetter, and it is a water-loving plant (a hydrophyte). This will mean that the leaves of Ranunculus Repens will have a reduced or completely absent waxy cuticle and stomata as there is no need to conserve water, also they will have a greatly reduced root system as roots do not need to stretch deep into the ground to find water, and there will not be as much supportive tissue as the water provides enough buoyancy. If there are problems identifying Ranunculus Repens, a microscope could be taken to recognize these special features . Wet soil

  • Word count: 1089
  • Level: GCSE
  • Subject: Science
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Enzymatic Juice Extraction - Does the addition of pectinase, to chopped up apple result in a greater yield of apple juice, than if only water is added?

Enzymatic Juice Extraction Research question: Does the addition of pectinase, to chopped up apple result in a greater yield of apple juice, than if only water is added? Hypothesis: I believe that the addition of the pectinase enzyme will lead to a greater yield of apple juice than if only water is added. This will be because enzymes speed up reactions. The pectinase will degrade the soluble pectin in the pulp which will in turn make the juices flow more freely resulting in a greater yield of apple juice in a set time period. Water does not act so fast on the pectin and so a small yield will be expected in the same time period. Variables: Time Controlled Amount of apple Controlled Addition of water/pectinase Independent Temperature Controlled Apparatus: Apple Pectinase Coffee filter papers Knife Glass stirring rods 1cm³ syringes Filter funnels 100cm³ measuring cylinders Beakers Water bath Stopwatch 50ml beaker Method: The apple was crushed into small pieces and these were divided between two 50ml beakers, 2 cm3 of diluted pectinase enzyme was added to one of the beakers, and 2 cm3 of water to the other. The beakers were stirred with a clear glass rod and then incubated in a water bath at 40ºC for 15-20 minutes. The juice from the apple pieces were then filtered using coffee filter papers in funnels placed in measuring cylinders. The volume of

  • Word count: 588
  • Level: GCSE
  • Subject: Science
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Should whale hunting be banned?

Should whale hunting be banned The debate over whale hunting has raged for a number of decades. I will investigate both sides of the argument and decide for myself through my research which side to take. Whale hunting, formally known as whaling, has many benefits but also has major effects on the endangered species. For me to take sides I will first need to explore all different points of views and understand the reason why different people have different opinions on the topic of the banning of whaling in the world. Commercial whaling was banned globally in 1982, but Iceland, Japan and Norway continue to hunt under under the guise of scientific research, collectively targeting more than 2,000 whales each year.The IWC does not have the capacity to enforce the moratorium. Sea Shepherd, guided by the United Nations World Charter for Nature, is the only organization whose mission is to enforce these international conservation regulations on the high seas. For One of the biggest reasons in favour for a ban is the conservation of whales. Many see killing whales to the extent or near extinction is morally wrong. That's why blue whales are not being hunted whereas minke whales. Many question the if Japan continue whale hunting for cultural reasons rather than scientific. Whales are hunted by explosive harpoons. Anti-whaling campaigners say the method of killing is cruel.

  • Word count: 532
  • Level: GCSE
  • Subject: Science
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Water is Essential for Life

Water is Essential for Life Water is one of the most commonly found molecules on planet earth and it exists as rivers, lakes and oceans. It is present as vapour within the air and surrounds plants and animals at all times, it are the habitat for many organisms. Obviously, water has an important role in biological life. It now makes up 60-90 per cent of the fresh mass of living organisms and consists whilst playing a large role within all or many cells. This essay refers to the many biological, chemical and physical features of water. It discusses the properties of temperature control, electrolyte balance, transport mediums, chemical reagents and health. A water molecule consists of an oxygen atom covalently bonded to two atoms of hydrogen. The two bonds form an angle of 105º but, because the oxygen bond is more electro-negative than hydrogen, the shared electron charge of the covalent bond is distributed more towards the oxygen, whilst the hydrogen atom has slightly positive charges making uneven charge distribution. This results in the molecule being polar and, because it is positive at one end and negative at the other, it is referred to as dipolar. Refer to diagram 1 for reference. [image002.jpg] Diagram 1 Since water molecules are polar, they have an attraction for each other and they form hydrogen bonds with other polar molecules. This ability to

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  • Level: GCSE
  • Subject: Science
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I predict that the stronger the solution (external) the more the potato chip will lose mass due to osmosis.

Osmosis - Plan Input Variable: Strength of water/sugar solution. Controlled: * Type of substance (in this case a potato chip). * Size of potato. * Conditions i.e. they are all in the same light and heat. * Volume of solution. Outcome: The change in length/mass of the chip. Prediction - I predict that the stronger the solution (external) the more the potato chip will lose mass due to osmosis. I have based my prediction on the theory of osmosis. When plant cells are placed in water, the water enters the cells. Each cell is surrounded by a cell membrane. It separates of the cell from the outside. The cell membrane has tiny holes in it. This allows small molecules to pass through but not large ones. The cell membrane is partially permeable. Osmosis is a special kind of diffusion to do with water molecules. It occurs when two solutions are separated by a partially permeable membrane. The stronger solution will absorb the molecules from the weaker solution. Therefore as the external solution Diagram Tin Foil H2O 5% 10% 20% 25% Salt Salt Salt Salt Apparatus > 5 Test Tubes; > 5 pairs of equal length potato chips; > Distilled Water; > 5%, 10%, 20%, 25% salt solutions (with water/ H2O); > Tin Foil; > Knife; > Ruler and Calculator. A fair Test Fair testing is an important part of this experiment and so to make sure the

  • Word count: 961
  • Level: GCSE
  • Subject: Science
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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

Biology Coursework To 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 across the valley, to find out why these particular plants grow in the particular places I mean to investigate where different species of plants are located and what the conditions in those particular places are, investigating the effects of several factors on the distribution of these different species across a specific area of the valley. I believe that the varied distribution of the different species investigated is directly related to, and can be explained by the differences in the factors I will be measuring, that certain plants will grow in certain places in the area because they are more suitably adapted, in whatever way to the conditions in that specific place. This is a rough diagram of Ellerbeck. I plan to perform my investigation using two information gathering techniques, after first establishing a straight line across the valley by taking a bearing using a compass from one point at the top of the South side of the valley and following that bearing down the valley, across the beck and up the other side whilst performing both a line transect and an interrupted belt transect. I also plan to perform an interrupted belt

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  • Level: GCSE
  • Subject: Science
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The affect of Light on Photosynthesis.

Photosynthesis Investigation The affect of Light on Photosynthesis Diagram Equation for photosynthesis :- Sunlight + Chlorophyll Carbon Dioxide + Water Glucose + Oxygen 6CO2 + 6H2O C6H12O6 + 6O2 Plan I am going to investigate the affect of light on photosynthesis. To do this I will carry out the same experiment as I did in my preliminary. I shall set up my apparatus, as shown in the diagram, and measure between the 250 watt lamp and the beaker. I will put marks at 20cm, 40cm, 60cm, 80cm and 100cm from the lamp. When the beaker and contained apparatus are at each point, I will time for 2 minutes and record the number of oxygen bubbles released from the Elodea stem. To see exactly how much oxygen is produced at each point, I will collect the oxygen in a cylindrical measuring tube or similar. I shall start by recording bubbles and collecting oxygen at the 20cm mark. This should get the elodea to start photosynthesising straight away, as opposed to starting at 100cm and waiting a long time for it to just start photosynthesising. I observed this during my preliminary experiment. My elodea started photosynthesising straight away, whereas some other students' elodea did not, and some did not photosynthesise at all. This is why I feel it is best to start as close as possible to the

  • Word count: 910
  • Level: GCSE
  • Subject: Science
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Investigation into the effect of Light Intensity on Photosynthesis.

Investigation into the effect of Light Intensity on Photosynthesis by Dominic Mulley Introduction Photosynthesis is the process that produces 'food' in plants. The 'food' that it produces is called glucose. Photosynthesis takes place in the leaves of all green plants. Leaves are especially to make photosynthesis: - Leaves are thin and flat to provide a large surface area to absorb as much sunlight as possible. - The palisade cells are near the top of the leaf and are packed with chlorophyll. - Guard cells control the movement of gases into and out of the leaf. They line the bottom of the leaf. An equation can be demonstrated to show how a plant produces photosynthesis and what substances it uses: Carbon + Water + Sunlight Glucose + oxygen Dioxide Chlorophyll 6CO2 + 6H2O + Sunlight C6H12O6 + 6O2 Chlorophyll The rate of photosynthesis depends on light intensity, carbon dioxide and temperature. Sometimes increasing these factors has little or no effect. This is because one of the other factors is so low that it limits the rate of photosynthesis. Scientists call this the limiting factor. Chlorophyll in green leaves uses light energy to perform photosynthesis. It can only do it as fast as the light energy is arriving. Chlorophyll only actually absorbs the red and blue ends of the visible light spectrum, but not the green light in the middle, which is

  • Word count: 1410
  • Level: GCSE
  • Subject: Science
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