Investigate the effect of huddling on heat loss.
Huddle investigation PLANNING A Aim: to investigate the effect of huddling on heat loss Hypotheses: . That the larger the huddle, the smaller the amount of heat lost. That is, an organism (test tube) on its own will lose more heat than if it were huddled in a group. In an experiment using test tubes, this will be supported by data which shows that a test tube by itself will lose more heat in the same amount of time than if it were in a huddle. 2. The temperature loss should decrease proportionally as the size of the huddle grows. 3. Also, the organism (test tube) in the centre of the huddle will lose less heat than an organism or test tube on the outside of the huddle. The reasoning behind this hypothesis is that as the huddle group grows in size, the amount of exposed 'surface area' will be reduced per test tube. Although in practice not every test tube is exposed, theoretically, this is a way of comparing huddles. Also, in a huddle of many organisms, or test tubes, if there is a centre test tube which is not 'exposed', it will be warmer than those on the periphery of the huddle. This hypothesis can be supported by data collected in the experiment by measuring the temperature of the centre of the huddle and the periphery of the huddle. The centre will be warmer because it has no surface area exposed to the outside. Huddling is a behavioural adaptation
Investigating Factors Affecting the Rate of Photosynthesis.
AT2 Biology Investigating Factors Affecting the Rate of Photosynthesis Stella Boachie How does Light Intensity Affect the Rate of Photosynthesis? Aim The aim of this coursework is to investigate whether light intensity affects the rate of photosynthesis. To do this, I will place a piece of Canadian pondweed in varying light intensities and observe the amount of oxygen given off. Introduction Photosynthesis is the process by which green plants and certain other organisms transform light into chemical energy. In green plants, light energy is captured by chlorophyll in the chloroplasts found in the palisade cells of the leaves and used to concert water, carbon dioxide and minerals into oxygen and energy rich organic compounds (sugar) that are the basis of both plants and animal life. The first step in photosynthesis is Light Dependent Processes (Light Reaction). Light strikes chlorophyll in such a way as to excite electrons to a higher energy state. In a series of reaction, the energy is converted along an electron transport process into ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate). Water is split in the process, releasing oxygen as a by-product of the reaction. The ATP and NADPH are used to make C-C bonds in the next stage of photosynthesis, Light Independent Process (Dark Reaction). In the Light Independent Process, carbon
Factors affecting rates of population change across the world.
Alex Calloway Factors affecting rates of population change across the world Throughout the world today, ones can see huge differences in rates of population change, from massive population growth rates to a gradual decline in population. There are some countries in the world today, where the rate of population change is extremely low and such a situation can occur for a number of reasons. When one reads of population growth or decline, it is impossible to avoid discussion of China's one child policy. However, this policy is an extreme violation of human rights and is limited to just one country and so should not form the basis of a discussion of population growth rates or as an example of a country with low growth rates. Instead, it seems apt to concentrate on those countries where government influence is not so draconian or tyrannical. Italy is one country with a negative rate of population change and does provide an example of many reasons why this situation can occur. Following the Second World War, Italy experienced a rapid process of industrialisation, geographically concentrated in the North, given Italy's current level of development and its late beginnings, it is simple to imagine how quickly the process occurred, as this graph, taken from www.thetimes.co.uk, shows. This development gave the citizens of Italy much improved health care provision, which in turn
Heat Energy Experiment Aim: To measure the heat energy released in a burning fuel.
Heat Energy Experiment Aim: To measure the heat energy released in a burning fuel. Diagram: Method: * The apparatus was set as shown in the diagram. * 20ml of water were measured. * The initial temperature of the water was measured as well as the distance from the tile to the bottom of the test tube. * The mass of the watch glass with and without the fuel was measured. * The fuel was lighted with a lighted splint and left to burn until it ends. * The mass of the watch glass was then re-measured. * The final temperature of the water was recorded. For safety reasons a heat-proof tile was placed under the watch glass and goggles were used. The fuel was lighted with a splint and not the Bunsen burner, and the experiment area was completely clear for space. For accuracy, the maximum temperature of the water was measured. The fuel was not left for a long time as the water would evaporate and the bottom of the test tube was cleaned in order not to interfere with the heating process. To make it a fair test, the time taken of different fuels to burn could be measured. If this happened, the apparatus should be properly washed, everything re-weighed and re-measured, and the thermometer left to cool. Results: (Averages) Ethanol Fire Lighter Distance from test tube to tile (cm) 2.5 cm 2.5 cm Initial temperature (ºC) 4.5 ºC 7.5 ºC Final Temperature
The Role of Energy in the Body and the Physiology of Three Named Body Systems in Relation to Energy Metabolism.
The Role of Energy in the Body and the Physiology of Three Named Body Systems in Relation to Energy Metabolism. I am going to describe the role of energy in the body and the physiology of three named body systems in relation to energy metabolism. Also I am going to explain the physiology of three named body systems in relation to energy metabolism. Energy Metabolism. Metabolism is the sum of all the chemical reactions occurring in human physiology and these will involve using or releasing energy from chemical substances. Roles of Energy in the Body. Energy is necessary for muscular activity and movement as you probably already know, however, energy is also necessary: * to circulate blood, lymph and tissue fluid throughout the body; * for breathing and taking in oxygen; * for making new cells for carrying out growth and repair; Also, * it is used to transmit nerve impulses so that we can respond to changes in the environment and; * it is needed to build different complex molecules such as enzymes and hormones from the simple molecules produced after diagnosis of food. Energy Supply to the Cells. The activities involved in energy supply include the roles of the: * Cardiovascular; * Respiratory, and; * Digestive systems. Further through I will be talking about the above in more detail but first, here is an overall view. The digestive system is responsible
Heat of Neutralization. Objective: To investigate the enthalpy changes () of various acid-base neutralizations.
Title: Heat of Neutralization Objective: To investigate the enthalpy changes () of various acid-base neutralizations. Chemicals and Apparatus: .0M hydrochloric acid, ~1.0M sodium hydroxide solution, one thermometer, one polystyrene foam cup with lid, two pieces of 50.00 burette, two filter funnels, one piece of 25.00 pipette, pipette filler and a 100 beaker. Background: All chemical reactions involve energy changes. The study of energy changes is an important part of chemistry. Fundamental to the thermo-chemistry is the law of conservation of energy, which states that energy is neither created nor destroyed, but can be converted from one form to another. An exothermic reaction is one in which stored chemical energy is converted to heat energy (heat is released to the surroundings), conversely an endothermic reaction is one in which heat energy is converted to chemical energy (heat is absorbed into the system). The enthalpy (H) of a substance, sometimes called its heat content, is an indication of its total energy content. The equation for calculating the enthalpy change (heat change) is given by ?H = -m x c x ?T where m is the mass of the sample, c is the specific heat capacity of the sample and ?T is the change in temperature. The sign for ?H indicates the direction of heat flow, positive for endothermic processes and negative for exothermic processes. In this
Investigation into the effect of acid/alkali strength on the heat change when acids and alkalis are mixed
Investigation into the effect of acid/alkali strength on the heat change when acids and alkalis are mixed Planning The main aim of this experiment is to investigate the heat change when acids and alkalis are mixed. The temperature of the acid and alkali that are going to be mixed will be taken prior to mixing, and after they have been mixed in a polystyrene cup. The maximum temperature rise will be noted as this will be the biggest heat change that has occurred. The highest temperature after mixing and the temperature prior to mixing will be subtracted to give the heat change. To ensure that this is a valid test the volume of the acid and alkali will be kept constant at 40cm3. The volume will be kept constant because if there were a differing volume of acid to alkali this would have an influence on the temperature rise as there is not the same amount of solution. The only variable in this experiment will be the strength of the acid and alkali. This will allow us to examine the manner in which the heat evolved differs for differing strengths. Comparisons can then be undertaken to see how concentration affects the heat change in set volumes of acid and alkalis. When the acid and alkali of the same volume are mixed, this will cause the process of neutralisation to occur. Neutralisation is the reaction between an acid and a base. It is the formation of a bond between
Discuss the relative importance of physical and human factors in accounting for changes to vegetation over time within ecosystems in the British Isles
Discuss the relative importance of physical and human factors in accounting for changes to vegetation over time within ecosystems in the British Isles The British Isles is an example of a Lithosere succession, in that it began as bare rock from glacial retreat. The plant succession started with the pioneer species which were algae and bacteria. Both began to broke down rock surface through weathering. Then lichens and mosses began growing in the area which helps with water retention and provides a base for soil. The next stage of primary succession is herbs/grasses/flowering plants/ferns. These add nutrients and organic matter to the ground which provided soil. Next, shrubs invaded and colonised the area. Shrubs dominate and shade out the sere below them. Small trees such as birch and willow were the following sere which invaded and colonised the area. They produced humus from leaf fall which provided nutrients for the soil through nutrient recycling and encouraged new growth of the sere. The last sere is the larger trees which are oak and ash which dominate the area and shade out smaller trees. This sere is the climax community in that it is stable and no further succession happens after. The climax community is the deciduous woodland biome we know today. The main characteristics include the location in which they are found, which is in temperate maritime climate such as
Investigating factors that affect the bounce height of a squash ball
SC1 Investigation 6/10/06 Investigating factors that affect the bounce height of a squash ball Christopher Lewis Candidate number: 2670 SC1 Investigation Investigating factors that affect the bounce height of a squash ball . Planning ) Investigating factors that affect the bounce height of a squash ball. 2) Background Information I have decided to investigate how the height from which a squash ball is dropped affects the height of its bounce. When a ball is dropped, it accelerates until it collides with the surface - an impact. It then recoils, and some of the energy is reflected back upwards, causing it to bounce. I believe that as the height from which the ball is dropped changes, the speed of the ball at the moment of impact will also change. This is because when the ball is dropped, it accelerates due to the force of gravity. Newton's law states that if the force acting on an object is not zero or the resultant force acting is not zero then the object will accelerate. In this case, the force acting on the object (gravity) is greater than the air resistance, so the object accelerates downwards. Theoretically, when the ball is travelling at a faster speed, there will be more force at the point of impact (due to the increased kinetic energy). Therefore, more potential energy will be stored in the ball as the collisions takes place, which will then be converted
Biology notes
AQA GCSE Biology Unit 2 Summary Notes 2.1 Animal and Plant Cells Cells * Cells are the smallest unit of life. * All living things are made of cells. * Most human cells, like most other animal cells, have the following parts: o nucleus o cytoplasm o cell membrane o mitochondria o ribosomes * Plant cells also have: o cell wall o chloroplasts o permanent vacuole What do these structures do? * Nucleus - controls the activities of the cell. * Cytoplasm - where most of the chemical reactions take place. * Cell membrane - controls the passage of substances in and out of the cell. * Mitochondria - where most energy is released in respiration. * Ribosomes - where protein synthesis occurs. * Cell wall - strengthens plant cells. * Chloroplasts - absorb light energy to make food in plant cells. * Permanent vacuole - filled with cell sap in plant cells. Other facts: * The chemical reactions inside cells are controlled by enzymes. Examples: o Enzymes for respiration are in the mitochondria. o Enzymes for photosynthesis are in the chloroplasts. o Enzymes for protein synthesis are on the ribosomes. * Cells may be specialised to carry out a particular function. Examples: Tissues, organs and systems * A tissue is a group of similar cells carrying out a particular function. * An organ is a group of different tissues carrying out a particular function. *
