The advantages and disadvantages of the biological control method of pest management?
Andrew Wilson The advantages and disadvantages of the biological control method of pest management The biological control method of pest management does not use chemicals. Biological control uses various organisms that are either predators or parasites to the pest. A pest is an organism which causes damage to people and their crops, however this is an economical definition, as opposed to a biological one. Something is considered to be a pest when it reduces productivity by 5-10%. Plants require certain mineral ions in order to grow well, however there is a limited amount of these in soil. Therefore if weeds are growing in a wheat crop, they will take some of the mineral ions that would go to the wheat plants. Interspecific competition is the competition between organisms of different species for the resources that they require, and intraspecific competition is the competition between organisms of the same species. Weeds also compete with crops for water and light as opposed to just mineral ions. Pests reduce the yield of plants in various ways. They can have a direct effect by damaging the leaves of the plant. Aphids feed by inserting their mouthparts into plant cells, this often results in leaves curling up and becoming distorted. Considering the leaves of a plant are the places where the majority of the photosynthesis takes place, it follows that a plant with stunted
Investigation of Microorganisms
Introduction For my AVCE Science coursework I will be doing an investigation into organisms; however I will be describing 2 of them in specific detail. The organisms that I will be investigation are: Barley Yeast Hen Farming I will be investigating in further detail of the barley and yeast. I have chosen to investigate the barley and yeast organisms because as part of my course I visited a brewery manufacturing company. I collected a lot of information on these two. While I was there I understood how barley is used towards the organisations success. Plan I will research the different types of organisms and compare them as well as research the to chosen organism and look at them in depth to get a better understanding. To increase my knowledge and give me a better understanding I will visit a brewing shop, preferably Carlsberg. I will gather information on how the brewing process is done. I will use relevant data collected from different websites and use the correct terminology, which I think is correct. Outlines of Barley It grows faster in cold conditions, it is an major food around the world, it is also used to feed animals such as horses, cattle etc. It mixed with other grains such as rice. A particular strain of barley found in China, it is effective in breaking down animal fats in the body. This was considered to be the poorer person's food source in the early
In the production of photochemical smog, there are primary and secondary sources that contribute to its production.
In the production of photochemical smog, there are primary and secondary sources that contribute to its production. Primary sources are injected directly into the atmosphere, whereas secondary sources are formed in the atmosphere through chemical and photochemical reactions. As the graph shows, motor vehicles (the red and pink columns) contribute largely to most of the primary pollutants. The main pollutants though are Carbon Monoxide and oxides of nitrogen (Nox). Motor vehicles also contribute largely to the secondary pollutant Nitrogen Dioxide. During the combustion of coal, primary pollutants are formed. Oxides of Nitrogen and Sulphur are formed because is there is both nitrogen and sulphur in coal - initially from the decomposed organisms. This becomes oxidised by burning. Oxides of Nitrogen are also created because there is such a high temperature of combustion, atmospheric nitrogen and oxygen form what is called thermal NOx (1). Photochemical smog is a condition that develops when primary pollutants interact under the influence of sunlight (2) to produce secondary pollutants. Several reactions lead to the production of the constituents of photochemical smog, taking place in the troposphere. Ozone is present in all levels of the atmosphere, even in unpolluted air. In unpolluted air, Nitrous Oxide reacts with the ozone, producing Nitrous Dioxide and Oxygen: 03 + NO
The Effect of Substrate Concentration on the Rate of Reaction
The Effect of Substrate Concentration on the Rate of Reaction Aim: The aim is to look at how the rate of reaction in yeast catalase is affected by a particular substrate concentration. The substrate that is used in this experiment is hydrogen peroxide on the yeast catalase, which will bring faster and more precise results. Enzymes only work with substrates that fit their active site, called the lock and key mechanism. This is where the substrate fits into the enzyme in the same way that a key fits into a lock. During the process, a substrate is fitted into an active site of an enzyme. Not all substrates fit in, only particular ones, hence, the 'lock and key'. When they are together, the enzyme - substrate complex is made into a product. This is when the bonds in the substrate are weakened. The products are left from the enzyme, leaving the enzyme unchanged after the reaction. The reaction is a catabolic reaction, which means the yeast catalase breaks down the hydrogen peroxide into water and oxygen gas. H2O2 H2O + O2 Apparatus Used: . Stop watch. 2. Measuring Scale. 3. Stand with clamps. 4. Gas syringe. 5. Measuring cylinder. 6. Clonical flask. 7. 1.5 grams of yeast catalase. 8. 4 cm³ of hydrogen peroxide of various concentrations. Method: . 1.5 grams of yeast catalase has to be measured. 2. The
I am going to investigate respiration in crickets and how temperature varies the rate of respiration.
Planning I am going to investigate respiration in crickets and how temperature varies the rate of respiration. The calculation for aerobic respiration is: Oxygen + Glucose Carbon dioxide + water + energy 6O2 + C6H12O6 6CO2 +6H2O + (J) I will do the experiment safely by making sure that the water will not be too hot or too cold, this is a safety precaution for me as well as the crickets. As we don't want to cause the crickets too much distress or pain. It will be a fair test and accurate because I will: * Use the same crickets * Same mass of crickets * Let the crickets return to room temperature * Reset the measuring device after each experiment * Do each experiment 3 times to get an average I predict that the lower the temperature the lower the rate of respiration. Equipment list: * 2 beakers- a lager one that will hold the different temperatures of water, a smaller one to hold the ink marker. * Crickets- to test on * Bung- containing delivery tube and waste (reset) tube * Ink- to mark distance on the scale * Delivery tube with scale on- to mark distance * CO2 remover- to remove the CO2 * Excess tube for reset. I will measure the amount of oxygen used by the crickets by measuring how far the ink marker has traveled up the scale, the rate of respiration at different temperatures and conditions. The variables that affect the rate of
Costs of Cigarette Smoking on Human Health
'The costs of cigarette smoking on human health' Nicotine is an addictive drug. When you smoke a cigarette, your body responds immediately to the chemical nicotine in the smoke. Nicotine can cause a short-term increase in blood pressure, heart rate and the flow of blood from the heart. It also causes the arteries to narrow. Smoke includes carbon monoxide, which reduces the amount of oxygen the blood can carry. This creates an imbalance between the need for oxygen by the cells and the amount of oxygen the blood can supply to the body. The effect of smoking on human health is something which has been highly studied over the recent years. Each year, more and more people are trying to quit due to the recent restrictions brought in on smoking in public (June 2007) however only 5% of nicotine addicts manage to "quit" (How Drugs Work 2nd Edition by Hugh McGavock). More research is being done looking at the effects smoking can have on smokers and the people around them. It is estimated around 111 000 people in the UK die every year due to smoking. (A New Introduction to Human Biology by Indge, Rowland and Baker). Smoking can also contribute to death through lung cancer, bronchitis and emphysema. I know smoking can cause a number of diseases, the main one being cancer. Smoking is the single biggest cause of cancer in the world, and accounts for one in four UK cancer deaths
The effects and importance of the carbon and nitrogen cycle
Effects and importance of the carbon and nitrogen cycle Carbon is the basis of all life. It is the backbone of organic matter whereby other elements can bond to it to form complex specialised polymers used in the functioning of organisms. The two most important features of carbon is that it has a valence of four allowing it to bond to other life essential elements and that the energy input required to make and break bonds is at a level where molecules and complex organic polymers can form. The composition of dietary nutrients like Lipids, proteins and carbohydrates all contain the element of carbon. And so through does the enzymes required to act upon and digest them. It is because of carbon's ability to bond to other elements like oxygen, hydrogen and nitrogen that this can happen. As each individual carbon atom has the ability to hold eight electrons in its outer shell it can form four other bonds with four other elements. Carbon can also form bonds with itself and as well as single bonds it can also make double bonds with other elements. This allows carbon to form a variety of compounds all differing in sizes and shapes such as cellulose, keratin, chitin and other vital polysaccharides as well as being a fundamental element in all forms of organic matter. This shows the linkages that relies on carbon in cellulose, a major component in the structure of a plant.
The Role of Lipids In Living Organisms
The Role of Lipids in Living Organisms Lipids can be defined as "a group of substances that contain carbon, hydrogen and oxygen, as do carbohydrates, but in lipids the proportion of oxygen is much less."(1) They are also defined as "hydrophobic (insoluble in water) yet are soluble in organic solvents like ethanol, chloroform and ether"(2). Lipids are a diverse group of organic compounds and so can be classified as: . "Simple lipids, the animal fats, the vegetable oils and the waxes 2. Complex lipids 3. Phospholipids and related compounds 4. Steroids"(2) "Tryglycerols are formed by a condensation reaction that takes place between glycerol (an alcohol) and monocarboxylic acids (fatty acids)" The result of this reaction gives rise to a molecule of triglycerol and is used by living organisms as a source of energy store. When broken down lipids in the form of tryglycerols yield "38 kJg-1 of energy which is twice as much as the amount of energy that carbohydrates yield, 17kJg-1"(3). Another reason for using lipids as an energy store as oppose to carbohydrates is that lipids are more compact and insoluble in water. They are more compact because lipids, "tend to be only minimally hydrated and, in turn, clumps of lipids (hydrophobically excluded) take up even less volume (and mass) than storage carbohydrates"(4) The role of tryglycerols goes beyond energy storage. Tryglycerols,
Comparison and Evaluation Of Energy Sources
Comparison and Evaluation Of Energy Sources Compare and contrast particular advantages and disadvantages of using different energy sources to generate electricity At this point in time there are four options being considered to produce power for us instead of the two standard methods. Firstly, however, lets look at those two conventional means of producing power: In the United Kingdom, the method used most widely is by burning fossil fuels. 70% of the electricity for the United Kingdom is produced by 70 coal fire power stations. The fossil fuel, coal, is burnt in a large furnace, and the boiling tube is placed above it. From this comes steam and water vapour which then powers the turbines, producing alternating current. The rotor, made of large electromagnets, turns at a speed of 3000 revolutions per minute. And then electricity is produced at 22000V, whilst the steam is sent to the cooling tower. But there is a great waste. Using trains and diggers to transport different materials around wastes energy, whilst more is lost in the form of heat energy when the steam is sent to the cooling towers. There are also great environmental costs that are paid as it releases poisonous gases: carbon dioxide and sulphur dioxide. For the same amount of energy released, coal produces more carbon dioxide than oil, which produces more carbon dioxide than natural gas. There is no
An Investigation into the Effects of a Single Factor on the Rate of Transpiration of 2 Different Species of Plant
An Investigation into the Effects of a Single Factor on the Rate of Transpiration of 2 Different Species of Plant. The aim of this investigation is to determine and compare how variation of a named factor affects the transpiration rates of 2 different species of plant. The process of transpiration is the process in which water vapour is lost from within the plant and goes into the atmosphere. It occurs only when stomata are open on the leaves of the plant which allows the water vapour to pass through going to the lower water potential outside the leaf.(1) The actual rate of the transpiration can be effected by many different factors including light intensity, wind speed, temperature and humidity of air surrounding plant. In this investigation I am going to look into how one of these factors affects the rate of transpiration of 2 different species of plant. Factor (variant) = wind speed Plants = holly and privet To get a fair investigation then the other factors must be kept as constants i.e. they must remain the same throughout the experiment whilst taking results as if they are not the results may be inaccurate and inconsistent in respect to what they should be. I think that as wind speed increases the rate of transpiration will increase, this is because the wind intensity will be getting rid of the vapour lost from the plant quicker and therefore the water potential
