An experiment to investigate the effect of Light intensity on the rate of photosynthesis.
AN EXPERIMENT TO INVESTIGATE THE EFFECT OF LIGHT INTENSITY ON THE RATE OF PHOTOSYNTHESIS. Prediction As the light intensity increases, so the rate of photosynthesis will increase. The rate of photosynthesis should be directly proportional to the intensity of light directed, given that the other possible variables remain constant. There should be an optimum temperature above and below which the rate of photosynthesis will be lower. I expect that this temperature will be 30oC and therefore, this is the temperature at which the experiment will be conducted. I chose this temperature because the 25oC used in the trial did not produce the optimum conditions for production of oxygen. The oxygen is formed by the combining of carbon dioxide and water to make glucose and oxygen. The glucose is needed by the plant as a source of energy and the oxygen is just a waste product of this process. Carbon Dioxide + Water Glucose + Oxygen 6C02 + 6H20 C6H12O6 + 602 (Nuffield co-ordinated Sciences Biology) This equation relies on the unlikely occurrence of twelve different molecules all reacting in the same place at the same time and in the right order. There are in fact, two different stages of photosynthesis, one light stage and one dark stage. This means that it is much more likely that the reaction will take place as it is broken down into simpler stages. All of the
Investigation into the affect of Osmosis in Potato Tissue.
Investigation into the affect of Osmosis in Potato Tissue. Introduction. Water potential, w, 'is a measure of the ability of water molecules to move from one region to another'. (1) The more water molecules there are per volume of the cell the more likely that, by random movement, they will collide with the cell's plasma membrane, and travel out of it. Pure water has a w of 0. As all solutions have less water molecules per volume than pure water they have a lower w; therefore all solutions have negative water potentials. The movement of water molecules is not totally random, the net movement of water is known as Osmosis. Osmosis is a special form of diffusion, which involves the movement of water. Osmosis can be defined as: The movement of water, through a semi-permeable membrane, from an area where it is highly concentrated to an area where its concentration is lower. The water molecules move down a water potential gradient until equilibrium is reached. Equilibrium is reached when the water potentials on both sides of the plasma membrane are the same. Water potential, w, is equal to the solute potential, s, plus the pressure potential, p. Therefore: w = s + p Potato and celeriac are both tubers, 'a thick rounded part of a stem or rhizome, usually found underground and covered with modified buds'. The root vegetables potato and celeriac were used because there
Investigating Gas Production By a Green Plant During Photosynthesis.
INVESTIGATING GAS PRODUCTION BY A GREEN PLANT DURING PHOTOSYNTHESIS INTRODUCTION: To investigate gas production by a green plant during photosynthesis. Photosynthesis occurs only in the presence of light, it 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: AIM: I am going to investigate how varying light intensity will affect gas production by a green plant during photosynthesis in a plant. To do this I will need to cut a piece of Canadian pondweed and place it into a beaker containing a little bit of sodium hydrogen carbonate. A lamp will be shined onto the pondweed and the amount of bubbles released from the plant will be counted. The lamp will be adjusted to different distances from the plant to try and get different results. FACTORS WHICH AFFECT THIS REACTION ARE: * Light Intensity * Carbon Dioxide * Water * Temperature LIGHT INTENSITY: Pigments in the leaf such as chlorophyll take in light. Chlorophyll absorbs all different coloured types of light, it absorbs blue light, and also easily absorbs red light, and however, chlorophyll does not absorb green light or yellow light effectively. But it tends to reflect them, which decreases the amount of light absorbed,
Test to find if the rate of photosynthesis increases or decreases when a piece of Canadian Pond Weed is put in a tray of water with a lamp at different distances
Aim- My aim is to test if the rate of photosynthesis increases or decreases when a piece of Canadian Pond Weed is put in a tray of water with a lamp at different distances. Introduction- Photosynthesis is a procedure that takes place in the leaf. The formula is: Photosynthesis takes place when the chlorophyll (that is in the chloroplast) converts the carbon dioxide and water (with a little help from light and chlorophyll itself). Which is turned into glucose (which is then turned into starch which is used for energy) and oxygen (which is passed out through the leaf as a waste product). There are a few things that could limit the rate of photosynthesis, these are the amount of carbon dioxide, the amount of minerals, the temperature, the amount of water and the amount of water (this is what our experiment is based on). The cells that carry out photosynthesis are called palisade cells. These are rectangular and full of chloroplasts. Lots of palisade cells make up the palisade tissue. All the cells make up a tissue that makes food for the plant. Energy is needed in photosynthesis. The energy comes from sunlight. Chlorophyll is a substance that absorbs sunlight. The light energy is used to convert carbon dioxide and water into sugars. The sugars are the plant food. Oxygen is made as a waste product. During photosynthesis the energy from the sunlight becomes converted into the
Why is Water Essential to Life.
Why is Water Essential to Life A water molecule contains an oxygen atom and two hydrogen atoms. The two Hydrogen atoms are attached at an angle of 105° (shown in picture below). On the bottom there are two pairs of electrons that form a 90 degree angle. On earth, water is found as a liquid, as a solid (ice) or as a gas (water vapour). Water molecules are attracted to each other, creating hydrogen bonds. These strong bonds determine almost every physical property of water and many of its chemical properties too. The main properties of water are: Weight: 62.416 pounds per cubic foot at 32°F, Weight: 61.998 pounds per cubic foot at 100°F, Weight: 8.33 pounds/gallon, 0.036 pounds/cubic inch, Density: 1 gram per cubic centimetre (cc) at 39.2°F, 0.95865 gram per cc at 212°F Water is a polar molecule and because electrons are more attracted to the positively charged oxygen atom, the two hydrogen's become slightly positively charged (they give away their negative charge) and the oxygen atom becomes negatively charged. This separation between negative and positive charges creates what is known as a polar molecule, meaning a molecule that has an electrical charge on its surface somewhere. Although the water molecule as a whole has no charge, the parts of it, the hydrogen wings and the oxygen body, do exhibit individual charges. Because water is a polar molecule this allows
An Investigation into how light intensity affects the rate of photosynthesis.
An Investigation into how light intensity affects the rate of photosynthesis The aim of this activity is to observe and justify how the amount of light intensity exposed to a plant affects the amount of photosynthesis the plant performs. I am trying to investigate the affect of light intensity on photosynthesis on a plant. My hypothesis is that as the light intensity on the plant increases, the photosynthesis the plant performs will also rise proportionally. However I also hypothesize that when a certain level of light intensity is reached, the rate of increase will itself decrease. At this point temperature may become a limiting factor, which there is no control of. Light is needed along with Chlorophyll to create a chemical reaction so that this conversion can take place. Without light, this cannot happen, and chlorophyll, found in chloroplasts cannot convert water and Carbon Dioxide. The light comes as light energy and is converted into chemical energy to convert the water and C02 into Glucose and Oxygen, which is just a by-product. Furthermore, because of this, the greater the amount of Light, the more conversion there would be taking place and the quicker it would take place. Because of a greater intensity of light, there would be a greater amount of chemical reaction in the same or smaller amount of time. However, a limiting factor is also needed to be seen. In
To determine how the concentration of salt water affects osmosis in potatoes
Investigation - To determine how the concentration of salt water affects osmosis in potatoes Planning Aim - To determine the effect the concentration of water has on osmosis in potatoes Prediction - I think that when the concentration of salt water is higher then there will be a greater loss of weight in the potatoes. This is because the water molecules inside the potato move from an area of high water concentration to low water concentration. When the concentration of salt is higher it will therefore have a lower water concentration meaning that there will be a steeper concentration gradient. The salt molecules will not diffuse into the potato because they cannot pass through the partially permeable membrane. I think that in all the salt solutions above 1% the potato will become plasmolysed. Whilst this doesn't usually happen the potato will be surrounded by solutions of a very high concentration. It will become plasmolysed because a lot of water will have left the cell to the point when the cell wall can no longer shrink and the cell membrane will tear away from the cell wall. This will kill the potato cell. A diagram of a flaccid cell is shown to the right. In 0% solution (water), the cell will become turgid and therefore gain weight. This is because when plant cells are put in pure water the plant cell will take in water and swell. The cell wall will prevent it
Effect of coppicing on Abundance of Violets.
Effect of coppicing on Abundance of Violets PLAN Introduction A natural woodland ecosystem contains rich sources of wood such as oak and beech that humans want to exploit. It contains a stable community of plants, insects and birds. Coppicing is a method of cutting trees near the bottom and allowing them to grow with many branches at the bottom. This is designed to be more efficient for man but allows this climax community to exist as naturally as possible. It could also be proved to benefit wildlife such as increased nesting places for birds. This cycle has been implanted in the woodlands on Weald clay wild in Sussex. A woodland ecosystem is made up of four layers, starting from the top, canopy, shrubs, herbaceous layer and the ground layer. A lot of the time these intermix and it can be difficult to distinguish. Pale wood violets (viola reichenbachiana) are perennial plants that grow in hedges and banks in areas of deciduous woodland. Due to its high phenotypic plasticity (grows along hedgerows and woodlands), they are abundant in coppiced areas. Woodland Violet is a low growing plant and can be identified by their pale heart-shaped leaves. The flowers are violet (with dark purple veins). Early Dog Violet are another type of violet which are very hard to distinguish that also grow in woods and shady habitats among the pale wood violets. Violets are sciophytes
An investigation into the effect of a germination inhibitor on the germination of seeds.
GERMINATION INHIBITORS An investigation into the effect of a germination inhibitor on the germination of seeds. INTRODUCTION The necessary conditions For a seed to germinate there are specific conditions different seeds need. In this experiment, cress seeds are to be used. Going through the basics first though, for a seed to successfully germinate there needs to be: o An adequate supply of water o A suitable temperature o An appropriate partial pressure of oxygen o A suitable supply of light Water uptake is a crucial part of the necessary conditions because germination can only commence after the uptake of water by the seed. Water absorption is imbibition. The optimum temperature for germination is the optimum for the enzymes involved in mobilisation of food reserves, provided that other factors are not limiting. This temperature varies from species to species (i.e. 1 - 45°C). Respiration makes available the energy for metabolism and growth. Germinating seeds respire very rapidly, and require oxygen for aerobic respiration. Seeds will not germinate in the total absence of oxygen. Diffusion of oxygen through the testa may be slow, however, and in the early stages of germination seeds may rely on some anaerobic respiration, at least until the testa has ruptured. So this explains why water, oxygen and a suitable temperature are needed for germination, therefore
Water and the Environment
Environmental Relationships and Issues- Water and the Environment Dear Mr. Tredinick, I am writing to you as I am disgusted at the state of the rivers in the countryside, I am sure you are unaware of these issues as no action has been taken to try to solve this problem Here are a few cases of the very many rivers which have suffered: Site - River Kennet Problem Low flows caused by Water Company licensed abstractions. Taking water could lead to the river drying up, killing wildlife such as Water Crowfoot and the Desmoulin Whorl Snail. Low water levels could also prevent vegetation on banks of rivers not to grow. Solution This problem could be resolved by monitoring and limiting the amount of water being abstracted from this river. You could also make a change in the contract with the Water Company by limiting the amount of water taken in the summer so the river doesn't dry up, you could also keep extra water in storage in the winter so you don't need to abstract in the summer. Monitoring & limiting water abstraction and buying storage containers would mean hiring new staff or buying new technology, either way money would have to be spent, this means that water rates would have to be increased. The public would have to decide what they wanted, increased rates or things leaving the same. Though a recent poll done by English Nature shows that 95% of customers wouldn't
