Title : The Determination of Microbial Numbers Objectives:Practically every phase of microbiology requires method for measuring microbial numbers. Study the theoretical relationship of one bacterial cell, or clump of cells.

Experiment 4 Title : The Determination of Microbial Numbers Objectives: * Practically every phase of microbiology requires method for measuring microbial numbers. * Study the theoretical relationship of one bacterial cell, or clump of cells. * Study the effect of dilution to the bacteria growth. * Determine the cell masses of a culture in order estimates the total cellular protoplasm per milliliter of culture. * To learn both quantitative plating methods which are spread plate and pour plate to measure the number of bacteria. * To understand the measurement for the number bacteria by performing plate and dilution count. Result and Observations: Part I: Spread Plate Unlabelled sample - Dilution factor 10-1 Sample A - Dilution factor 10-2 Sample B - Dilution factor 10-3 Sample C - Dilution factor 10-4 Observation: According to the observation, the result is showed that the colonies of E.coli cultures are too numerous to count via normal visible with density diminish from sample A to sample C. As a result, we get the accurate number of colonies for each plate in the experiment doesn't count for calculation. For the unlabelled plate sample that was showed off, we discover that Whitish strands of colonies were observed apart from the usual circular whitish colonies which are produced by E.coli bacteria. Part II: Pour Plate Sample A - Dilution factor 10-4

  • Word count: 2570
  • Level: AS and A Level
  • Subject: Geography
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The aim of this piece of coursework is to investigate the impact of tourism, and a Park and Ride scheme, on the natural limestone environment of Cheddar.

The aim of this piece of coursework is to investigate the impact of tourism, and a Park and Ride scheme, on the natural limestone environment of Cheddar. Cheddar is just forty-five minutes away to the south east of St Gregory's Catholic Comprehensive School. The A18 is the road that we first took to get to Cheddar and then we took the B3135 to get into the gorge, as you can see on the map on page . We visited Cheddar to collect primary data and to investigate the type of limestone and its features. This trip was organised so that we could see the limestone for ourselves instead of looking at other sources like books or the Internet. The visit to Cheddar also enabled us to a cross unit task. This was, water, landforms and people, and people work and development. In this coursework I shall include information on Carboniferous Limestone and how it is formed. I shall also give an introduction to Cheddar and the different parts of it such as the Gough's caves and Aladdin's caves and the gorge. Maps will also be included so that you can get an idea of where Cheddar is located and how far away it is from certain places. In task 2, various graphs shall be made which will show the information on all the surveys I took in order to help me in my coursework. Task 3 shall include the different views of the people that would be affected if the proposed Park and Ride, shown in the grid

  • Word count: 1219
  • Level: AS and A Level
  • Subject: Geography
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Ecology of Sand Dunes.

Ecology of Sand Dunes There are six main physical types of dunes which rely on the position of the system in relation to the direction of the shoreline. Three of these being spits, offshore islands and nesses project towards the sea and are generally extending seawards. They are characterstic where the prevailing wind is offshore so in England would be the East Coast. The other three types which are bay dunes, hind shore dunes and machair are found found where the prevailing wind is onshore so a constantly being driven back on to the land behind the shore by the wind and are found on the west coast. Dunes are known as sub-maritime coastal habitats as they are not plagued by occasional flooding and are not very salty. Dunes can very in size greatly with the height increasing over 25 meters on some coasts and can vary greatly in width and length. Dune vegetation Dune vegetation varies according to stability, moisture content and calcium carbonate content of the sand the dune is made up of. In order for vegetation on the dunes to grow plant succession has to occur. Marram grass colonises the dune (fore dunes) and spreads its tuberous roots just under the surface of the sand, and forms an underground web that helps hold the sand in place. Though marram grass stabilizes the soil for its own survival, an inadvertent side effect is that it makes it possible for other kinds of

  • Word count: 797
  • Level: AS and A Level
  • Subject: Geography
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Cholera - its global impact

Cholera Cholera is an infectious disease caused by the bacterium Vibrio cholera, which usually spreads through contaminated water. It affects the absorption of water in the small intestine and in severe cases produces severe diarrhoea. The most dangerous aspect of Cholera is the immense loss of fluid that can occur within a few days. Without treatment within 24 hours of developing the disease, the loss of fluid can be fatal. Many cases, such as those in Zimbabwe, require hospitalisation of infected people so that fluids can be administered straight into the bloodstream with the use of a drip. Cholera bacteria occur naturally in coastal waters, where they attach to tiny crustaceans called Copepods. The Cholera bacteria travel with the Copepods, spreading worldwide as the crustaceans follow their food sources, which are certain types of algae and plankton. These grow rapidly when the water temperatures rise and algae growth is further increased by the urea found in sewage and agricultural runoff. Therefore most Cholera outbreaks occur in spring and autumn when ocean surface temperatures and algae blooms are at their highest. More algae mean more Copepods, and more Copepods mean more Cholera bacteria. The map on the left shows that the areas that Cholera is discovered in are situated below the Brandt line. This is because these areas are surrounded by warm oceans where the

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  • Level: AS and A Level
  • Subject: Geography
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The number of fatalities that result from volcanic and seismic natural hazards is related to the level of development in the country in which they occur. Discuss.

The number of fatalities that result from volcanic and seismic natural hazards is related to the level of development in the country in which they occur. Discuss. A natural hazard is an event, linked to the physical environment, which is considered to have a negative effect on humans. The event is also seen to be unpreventable by humans. However, an event such as a volcanic eruption that has no effect on human beings is considered a natural phenomenon rather than a natural hazard. It is the presence of humans, in an area that such an event occurs, that allows it to be termed a hazard. Although humans cannot prevent these occurrences, they have a role to play in the event's extremity as a natural hazard. For example, volcanic eruptions have been present throughout history, but it is not until settlements are built on the rich soils they form that they become a hazard. This essay I will evaluate the extent to which the level of development in a country affects the number of fatalities caused by volcanic and seismic natural hazards. A volcanic natural hazard is a volcanic eruption. Volcanoes are formed at convergent and divergent plate boundaries and also at hot spots. At convergent plate boundaries eruptions tend to be from a vent, as oceanic crust is forced beneath another plate, the extremities of heat and pressure leads to the partial melting of the crust which is being

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  • Level: AS and A Level
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River Mississippi

RIVER MISSISSIPPI Hydrosphere A Case Study of * River management * People interfering in the hydrosphere * A flood management scheme River Basin / Catchment area The source of the river is the eastern side of the Rocky Mountains and the Appalachian Mountains to the north. There are many hundreds of tributaries including the Red River, Missouri river and the river Ohio. The mountains form the river's watershed. From Minneapolis the river flows South-East into Iowa where it flows south as far as Davenport. At Davenport it is joined by more small tributaries. From Davenport it meanders South to St. Louis, where it is joined by the Missouri. It then flows South-East, to be joined by the Ohio. It then flows 400 km before being met by the Arkansas river. It then flows South through Louisiana, to the Gulf of Mexico, where it splits into the many distributaries of its delta. How is the Mississippi controlled ? How & why used ? Benefits Problems Levees Mounds of earth are built parallel to the river, along its banks. These contain the rising river in flood times and protect buildings along the valley on the flood plain behind. * Known & successful technology which follows nature (rivers deposit silt to build natural levees anyway) * Protect settlements * Allow land close to the river to be used for economic gain * Concrete levees are a barrier to the

  • Word count: 460
  • Level: AS and A Level
  • Subject: Geography
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Climatic Hazards (Atmospheric Circulation)

Climatic Hazards (Atmospheric Circulation) Our planet is made up of many different climate zones that are located in different parts of the world and climate is the main reason why we have different areas such as rainforests and desserts. The main major climate zones are 'tropical' where rainforests are located at tropical latitudes on the equator with some exceptions, e.g. Indonesia. Australia and Northern Brazil are good examples of large rainforests. The sun is high up in the sky and these areas gain a lot of sunlight throughout the year averaging temperatures of approximately 34°c. Polar is a major climate zone and is of course mainly around the Poles b between 60-90°c North and South. These climates are very dry and freezing cold with fairly mountainous terrains e.g. Antarctica. Arid is a very important world climate and consist mostly of our very dry and warm areas e.g. our desserts. They are located around the tropic of cancer and tropic of Capricorn in countries such as North Africa where we have the Sahara dessert. These are very dry because prevailing winds come over the land and land masses are very large. Finally we 'temperate' climates such as in the UK which are located 40-60°c North and are fairly dry but can also be very wet and are also very cold with a lot of vegetation growth. I have stated that major climate zones are clearly caused by our climate but

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  • Level: AS and A Level
  • Subject: Geography
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To what extent is a knowledge of physical processes vital in understanding the occurrence of natural hazards?

To what extent is a knowledge of physical processes vital in understanding the occurrence of natural hazards? A natural hazard is defined as a natural event or process which affects people, for example causing injury or loss of life, economic damage, disruption to people's lives or environmental degradation. Physical processes create, maintain, and modify Earth's physical features and environments. Because the physical environment is the essential background for all human activity on Earth, it can be argued that a detailed knowledge of physical processes is vital in understanding natural hazards as a whole. Examples of physical processes include plate tectonics, climate and meteorology. When talking about how these physical processes help us to understand the occurrence of natural hazards, we mean not just when and how often they are likely to occur, but also where they are likely to occur - their spatial and temporal occurrences. Such hazards can also be measured in terms of magnitude, which is a measure of the strength of the hazard or of the energy released by it. This term usually refers to earthquakes but can also be used to refer to volcanic and other types of hazards. An example of where a knowledge of physical processes has helped to understand when a hazard will occur is Hurricane Katrina, which struck the south coast of the United States at the end of August 2005.

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  • Level: AS and A Level
  • Subject: Geography
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Temperature Inversions.

Temperature Inversions Normally, the air near the ground is warmer than the air at higher altitude. An inversion is the reverse situation--colder air at ground level than higher up. Cold air is heavier than warm air. Thus once an inversion forms, the air is very stable. Mixing that would normally occur by the rising of warm air is inhibited. Consequently pollutants such as carbon monoxide, sulphur compounds and ice fog remain trapped near the ground when there is an inversion. Types of Inversions The stability and mixing of air near the surface is controlled to a great degree by the presence of temperature inversions in the lower atmosphere. These inversions typically are very extensive, blanketing entire cities or regions. In each case, warm air is produced over a layer of cooler air in contact with the surface. There are basically four types of temperature inversions, each are explained below. Marine Inversions If you live near a coastline, you have probably experienced a marine inversion layer. Near cool oceans, such as in the western U.S. and Western Europe, a marine inversion can turn a hot summer day at the beach into a cool, foggy, overcast shiver. The ocean is typically quite cool compared with the land, particularly at middle latitudes where the heating by sunlight is not strong. Air sitting over cold water also tends to be cool. Moreover, a great deal of

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The Sahel and the ITCZ

The Sahel and the ITCZ Air masses moving over Africa have different characteristics depending on their areas of origin. Air originating over the tropical oceans, known as maritime tropical air, is warm, moist, and unstable. When this moisture-laden air is forced to rise and become cooler, condensation and precipitation often occur. Conversely, the hot, dry air that originates over the African continent (continental tropical air) is incapable of producing rain, even if it is forced to rise. Over most of Africa, air moves toward the equator. Northern Hemisphere winds from the northeast and Southern Hemisphere winds from the southeast converge at the intertropical convergence zone (ITCZ), a low-pressure zone centred on the equator. Air rises at the ITCZ, spreads out, and descends in the north and south, in subtropical high-pressure zones centred on the Tropic of Cancer and Tropic of Capricorn. After descending, the air flows outward, either pole ward into temperate regions or back toward the equator. The ITCZ constantly shifts its position, moving north of the equator during the Northern Hemisphere's summer, and south of the equator during the Northern Hemisphere's winter (see below diagram). This shift brings about seasonal changes, notably in the tropical summer rainfall zone. During the summer season (July to September in the Northern Hemisphere and December to February in

  • Word count: 889
  • Level: AS and A Level
  • Subject: Geography
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