Chemicals and the environment
CHEMICALS AND THE ENVIRONMENT Pesticides A pesticide is any substance or mixture of substances for preventing, destroying, repelling or mitigating any pest. www.epa.gov.html (office of pesticide programs) Pesticides can be used to control the numbers of pests which affect or reduce crop yields. They work by eliminating the organism or substance responsible for reducing crop yields as stated below. Pesticides are toxic substances deliberately added to our environment. They are used because they are toxic and biocidal- to kill and harm living things. www.pesticides/about.html In many ways crop plants are no different from plants growing under more natural conditions. They compete with other species for light, water and minerals. Insects feed on their leaves and die by being infected with viruses or fungi on the plant. This all reduces the overall growth of the plant and will most likely affect the number of seeds it produces which in turn reduces the yield of the plant. Crop farming today is based mainly on monoculture. With plants growing closely together insect pests and fungal diseases can spread rapidly meaning large areas are affected and heavy damage results in a short period of time. It is therefore important to control unwanted organisms that cause disease in order to obtain a good harvest. This is why the use of pesticides is extremely important in farming
'Genetic Engineering: Friend or Fiend'
'Genetic Engineering: Friend or Fiend' What is GM? A deliberate alteration to the gene of a living organisms e.g. animals, plants, or bacteria to change their characteristics, is said to be genetically modified. [2] It involves the combining of genes from different organisms to make a new gene, which would be placed inside the DNA of the species to be manipulated. E.g. a fish gene could be placed into a tomato gene. All organisms have the same genetic code which is made useful for the fields of medicine, agriculture, food and the environment. [3][6] (Tomato PIC)[5] How is Genetic Engineering applied to the world? GM is used in a range of fields ranging from agricultural settings to the making of medicines. Genetic engineering started around the 1960's and the development of techniques in the 1970's provided an increase for the productivity in agriculture. [1] Around 67.7 million hectares of land are used worldwide in 18 different countries to grow modified crops with two thirds of the GM crops being herbicide tolerant which means the crop is immune to the weed killer sprayed. Before GM products were developed, there would have been competition between the weeds and the crops for the nutrients and minerals in the soil. This caused the yield of crop production to be lower. [1] The United States is the most profitable country containing the largest amount of GM grown
Coconuts (Coco Nucifera) - Origin and Current Locales.
Coconuts (Coco Nucifera) Origin and Current Locales The word coconut comes from the Spanish and Portuguese word coco, meaning monkey face. This is because Spanish and Portuguese explorers saw a monkey's face in the three eyes on the bottom of a coconut. They discovered these fruits on the Nicobar Islands of the Indian Ocean, where they were used primarily as currency up until the early twentieth century. Palm trees, whereupon coconuts grow, for the most part, have not been intentionally imported into countries. This is because the fruit naturally disperses itself from one tropical beach site to another through flotation on water. The coconut is the seed of the palm tree. It can float for weeks and even months without sinking due to the coir, or brown fiber of the plant, which also protects the embryo from being damaged by the seawater. When the fruit finally washes up on a beach, the embryo germinates through one of the three eyes of the coconut. This explains how coconuts were growing and being used by Old World natives in the Americas before Columbus arrived. Coconuts can be found in any lowland tropical and subtropical region around the world. They thrive where annual precipitation is low and around beaches because coconuts are not affected by salt water of the ocean, like most other plants. Coconuts use the tides of the ocean to their benefit by helping
DeVries, Correns, and Tschermak.
Julie Solyar Honors Post-AP Advanced Topics in Biology Mr. Seigman December 11, 2003 DeVries, Correns, and Tschermak Three botanists, Hugo De Vries, Carl Erich Correns, and Erich Von Tschermark-Seysenegg, made possible for the spread and understanding of Mendel's work that has led to the modern understanding of the gene today. They re-discovered Mendel's laws in 1900 by independently working on plant hybrids. Their discoveries paved the way for the connection between Mendelian genetics and medicine, which was instigated by Archibald Garrod. This was complimented by greater discoveries in genetics, especially by Thomas Hunt Morgan, Herman J Muller, George Beadle, and Edward Tatum. Hugo de Vries (1848-1935) worked at the University of Amsterdam in 1880, as a professor of botany. Simultaneously, he worked on a series of genetic hybridization experiments. Working with the Oenothera lamarckiana (the evening primrose), de Vries was able to produce his theory of mutation. He agreed with discontinuous variation, staging that species evolve from other species by large sudden phenotypic changes. In his case, he noticed that a plant would usually have offspring that contained noteworthy differences from it such as leaf shape or plant size. These offspring would then occasionally pass these traits to their offspring. Ignoring that these traits observed in the primrose usually were
To investigate the soil type found at selected sites on the South West facing hillside and identify the factors important in the formation of the soil types found at these selected sites.
My Aim * To investigate the soil type found at selected sites on the South West facing hillside and identify the factors important in the formation of the soil types found at these selected sites. o Geographical processes that will determine the soil types found are weathering of the parent rock, mass movement and relief of the land. Since the Ercall is a steep hill mass movement will lead to deposition at the foot of the hill therefore making the soil here deeper. The steep hillside means leaching will take place in the mid slope forming podzolic soils while the foot of the hill will be waterlogged creating gleyed soil. * To investigate oak tree productivity and ground plant communities found at the selected soil sites. o Certain conditions are favourable for certain types of plants therefore depending on the different soil properties at each site different ground plant communities will be found. Oak tree productivity will also vary depending on the limiting factors found at the soil sites for example water logging. First hand data collection A stratified sampling method was used to select four different sites for soil data collection. This method was used as different rock types could be divided into subsets allowing a soil sample to be taken for each rock type. A Dutch auger was used at each site to bore into the soil. The soil removed showed the differences in
Adaptations of Aquatic and Tertiary Organism.
Adaptations of Aquatic and Tertiary Organism. Within plants water is transported up the stem via the process of transpiration. The stomata, as well as permitting entry of carbon dioxide, allow evaporation of water from the plant this is the process of transpiration. Transpiration occurs all over the plant through stomata in the stem and epidermis as well as in the leaves, however the adaptation of the leaf is its large surface are this means the main source of water loss is from the leaves. There is also "cuticular transpiration" which is water loss through the cuticles of the epidermis cells, these accounts for around 5% of water loss within the plant. The rate of transpiration is specific to the environment. Experiments with the potometer and an atmometer the rate of transpiration is dependent on a wide variety of internal and external factors. The opening between the stoma creates a chamber underneath the lower epidermis lined with spongy mesophyll cells, known as the "sub-stomatal air chamber". The number of stomata, their distribution, structural features and how open they are at the time. Externally many things effect transpiration, such as; . Temperature High temperatures encourages evaporation of water from the mesophyll cells 2. Relative Humidity, the degree to which the atmosphere is saturated with water vapour. This is important because it determines the
To see what affect trampling has on the diversity of plants, their abundance, and growth and to see the difference in varieties between a trampled and less trampled area.
Andrew Lightstone The Effects of Trampling on an Area of Plants Aim: - To see what affect trampling has on the diversity of plants, their abundance, and growth and to see the difference in varieties between a trampled and less trampled area. Preliminary work: - We went on a nature walk around the grounds of the school, to see the different varieties of plants and grasses in different areas. We noticed that in the area in front of one of the buildings where the children waited for the coaches, there were a lot less flowering plants, than in the area next to the football field where few people go. The differences between the sites, was due to trampling. We wanted to find out exactly how many more species of plants there were in the two areas, along with their abundance. In order to do this, we needed to carry out an experiment. Involved, we needed to see, on average, how many of each plant were in the trampled and non-trampled area. We could then compare them. Prediction : - There would be a greater range of plants in larger abundance, in an area that has rare trampling, as oppose to an area which is frequently trampled because the earth is less compacted so plants will lose air and nutrients. Also, in the area of less trampling, there would be more, of the taller growing plants and flowering plants and less little plants because less light is available to them.
History of the Loxley Valley (Near Sheffield, Peak district).
Neil Morbey, PLYMOUTH, 11/08/82 History of the Loxley Valley (Near Sheffield, Peak district) The other element that shapes the form of a landscape is the history behind it. This research delves into the past of the Loxley valley to try and understand these influences. Settlements. Settlements first recorded around the times of the Doomsday Book were not concentrated on the west of Yorkshire. But where some did locate was within the wooded valleys, such as the Agden and Rivelingdon (Now the Rivelin Valley). Agriculture and fields. This picture shows the Loxley valley's field patterns in the medieval period. It has a distinctive mosaic of small and medium sized fields; irregularly shaped, mainly walled, some still survive today. Some of these originated as early as the Iron Age, others have been taken in from the waste of scrub woodland, gorse covered heath and heather moorland in the medieval period and beyond. This is called 'asserting' and dates from the 14th and 15th centuries. The picture also shows the difference in the forms made by the parliamentary enclosure acts. Most enclosure acts were passed 1750-1830 and were there to allot all common land to owners and set specific legal boundaries. In 1649, Loxley Chase was described as 'the herbage common and consiteth of great oake timber.' After the enclosure acts of the eighteenth century it was divided into regular
Drought conditions, low and high temperatures, increased salt levels, pathogens and insects are common environmental stresses which plants are exposed to. Over time, plants have evolved unique mechanisms to respond to the stresses
Drought conditions, low and high temperatures, increased salt levels, pathogens and insects are common environmental stresses which plants are exposed to. Over time, plants have evolved unique mechanisms to respond to the stresses imposed in them. In response to pathogen infection, plants have two types of defence; constitutive and induced responses. Constitutive defences are those which are passive and always present in the plant. These defences are those such as the cuticle which is composed of waxes, cutin and pectin and the cell wall, composed of cellulose, pectin and lignin, both of which act as structural barriers against pathogens. There are preformed pathogen inhibitors such as saponins which disrupts pathogen cell membranes. For example, ?-tomatine in tomatoes acts against many fungal species. Other preformed inhibitors include alkaloids, phenols and tannins. Defence proteins are also present; lectins bind sugar groups such as chitin, which in fungal species binds to chitin in fungal walls and slows sungal growth. RIPs or ribosome inactivating proteins disrups viral replication by deactivating the plants ribosomes, therefore preventing cell replication and therefore also the viral pathogens replication. Hydrolases are present which break down the components of the pathogens and enzyme inhibitors inhibit enzymes which are used by the pathogen in the infection
Cannabis is one of the world's most commonly used leisure drugs. It's estimated that at least one person in twenty in the U.K. has used cannabis. What is it?
Cannabis CANNABIS is one of the world's most commonly used leisure drugs. It's estimated that at least one person in twenty in the U.K. has used cannabis. what is it? CANNABIS comes from the plant Cannabis Sativa, a relative of the hop plant, used for making beer. It has a leaf made up of 4-8 smaller lance shaped leaves with saw-toothed edges. When smoked, it has a sweet herbal smell. are there different types of cannabis? YES. The main forms of cannabis are: Cannabis resin - dark to light brown substance, scraped off the surface of the plant and pressed into a solid lump. It's often bought in street quantities from a sixteenth to a quarter of an ounce, but regular users may buy greater quantities. It comes from the upper leaves and the small leaves on the stem of the plant. The drug is sometimes taken on its own, but more often it is mixed with tobacco and smoked. Marijuana or Grass - dried leaves and/or flowering tops of the cannabis plant. It looks like dried herbs and is often mixed with stems and seeds; also often mixed with tobacco and smoked. Cannabis oil - a treacly liquid, refined from the resin or less frequently from the plant itself; often thought to be the strongest. It's either smoked by mixing with the tobacco, or smeared on cigarette papers, rolled with ordinary tobacco. what gives cannabis its effect? THE mind altering ingredient is a substance
