What is a species?

What is a species? "Species is a Latin word meaning 'kind' or 'appearance.'" (Campbell and Reece, 2005, p.473). However, clarifying what actually constitutes a species is controversial, as Biologists cannot agree on a specific definition of the word. Species is a term used by humans in attempt to place different 'kinds' of organisms into distinct groups using taxonomy - biological classification. A scientific name in the form of a binomial nomenclature is used to describe these groups. It is always written in italics with the capitalised Latin genus name followed by the species name. Species, therefore, is a fundamental category in taxonomy and important in the scientific naming of organisms. It is therefore essential for us to have a proper understanding of species. However, as a consequence of Biologists being divided in opinion on the nature of species, several concepts have been proposed to define the term. Therefore the answer to the question 'what is a species?' differs depending on which species concept is applied. The biological species concept (BSC) is the most frequently used and widely accepted definition of species. This concept was originally proposed in 1942 by biologist Ernst Mayr. Ernst Mayr stated that "species are groups of interbreeding natural populations that are reproductively isolated from other such groups." (Ernst, 1963 cited in Ridley,

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Evolution vs. Intelligent Design

Evolution vs. Intelligent Design Intelligent Design and Evolution are two major theories that have been observed in the history of science. Proponents from both sides argue that they use different methodological approaches to back up their theories, which invalidates their opponent's. There are several differences on their understanding of nature including the origin of life, natural selection, and the complexities the evolution. The most incompatible element of this debate is the methodological approach that either side takes in order to explain their understanding of nature. Whether they are really addressing the same issue is completely relative to how tolerant each side is of the other (should I clarify?) Despite their stark differences, both views have permeated the scientific and academic realms and have been accepted as popular theories worldwide. Although evolutionary ideas entertained the minds of ancient philosophers, it wasn't until 19th century when these ideas drew in legendary scientists (ie- Charles Darwin) and their harshest criticism. He addressed the concept of natural selection, in which life evolves through random mutations. Many concepts within evolutionary theory have been corroborated by scientific evidence. Scientists have been following DNA's footprints, which have been permanently engraved by concrete genetic research. Therefore, usually don't

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Examine the reasons for the existence and localities of biodiversity hotspots.

Supervision 2: Examine the reasons for the existence and localities of biodiversity hotspots "I have never experienced such intense delight... such a plenitude of forms, colours, behaviours-such a magnitude of Life! What explains the riot?" - Darwin (1851) "The current massive degradation of habitat and extinction of species is taking place on a catastrophically short timescale, and their effects will fundamentally reset the future evolution of the planet's biota." - Novacek & Cleland (2001) Biodiversity may be regarded as 'the number, variety and variability of living organisms' (MacDonald, 2003: 406). Whilst global variation in biological diversity has long been a source of fascination, it has recently been the basis for increasing concern (Tilman, 2000). Awareness of the extent and rate of the current biodiversity crisis (or the 'sixth extinction', as termed by Leakey & Lewin, 1996) has led to a significant re-assessment of the role of biodiversity in ecosystem functioning and the scope for policy intervention to enable its preservation, exemplified by the international ratification of the Convention on Biodiversity in 1992. The identification and analysis of spatial patterns of biodiversity has been central to conservation goals of maximum preservation at the least cost (Reddy & Davalos, 2003). The hotspots approach is one of many methods for delimiting areas of

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Elodea Plant Lab

Aquatic Photosynthesis of Elodea Leaves Lab Design Problem: What is the effect of temperature (warm, cool, room temperature) on the rate of photosynthesis in Elodea leaves measured by the levels of dissolved oxygen in the flask solutions? Hypothesis: If temperature is related to the rate of photosynthesis (levels of dissolved oxygen) then increasing the temperate will increase the rate of photosynthesis up to an optimal temperature. Variables: Independent: temperature of the water bath which the Elodea plant is immersed in Dependent: the rate of photosynthesis measured by the level of oxygen dissolved in the flask solution Constants: Relative size of the Elodea leaf, relative surface area of the Elodea leaves, (around 3 cm each), volume of water in all beakers, amounts of light exposure to the plants, and type of light source. Method: Materials: Light Source Elodea. Keep this warm and illuminated before you use it, 3 small flasks, 0g/L sodium bicarbonate (NaHCO3) solution, oxygen sensor Lab Quest data logger. Graduated cylinder Hot Plate 3 Large beaker (1 for warm water, 1 for cool water, 1 room temp) 3 thermometers Procedure: ) Day one: Before beginning the actual lab-Listen for teacher instructions and familiarize yourself with the LabQuest datalogger and its functions using the quick start guide. We will devote this day to learning how to use the

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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

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Compare and contrast the person-centered approach and cognitive-behavioural approaches to understanding and working with fear and sadness. Which of these two approaches do you feel more drawn to and why?

Compare and contrast the person-centered approach and cognitive-behavioural approaches to understanding and working with fear and sadness. Which of these two approaches do you feel more drawn to and why? -------------------------------------------------------- In this essay I will look[KHB1] at the key features of the cognitive behavioural approach and the person centered approach, I will look at the differences and similarities of the two approaches and explain why I am drawn to the person centered approach. The overall purpose of cognitive behavioural therapy is to increase self awareness, introduce better understanding, and improve self control by developing more appropriate responses to negative feelings. The goals of the person-centered therapy are to increase ones self-esteem, to have a greater openness to experience and to find out where you belong in life and be content with it. Both therapies help individuals to experience and express feelings at the moment they occur, rather than dwell on them at a later date. I will first look at the Cognitive behavioural therapy which was founded by Beck (1976), he believed that "the emotional and behavioural difficulties that people experience in their lives are not caused directly by events, but by the way they interpret and make sense of these events "as sited in Introduction to counselling p143. It is based on the fact that

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Biotechnology - Penicillin

What is biotechnology? Biotechnology is the use of technology to construct products or perform tasks through the use of biological systems and organisms.1Through history we have gained more knowledge of how biotechnology is applied and have refined and created new techniques that have benefited different areas, such as agriculture and gene technology. The application of fungal products has been in use for hundreds of years in the production of foods such as cheese and soy products. Penicillium mould (Penicillium chrysogenum2 ) contains the antibiotic substance penicillin, which was successfully isolated in 1945. Since Ancient times, moulds have been used to treat infection. Ernest Duchesne was a physician who discovered through experimentation, that Penicillium glaucum was able to destroy the bacteria, Escherichia coli. In his research, Duchesne was able to cure typhoid by injecting a subject with P.glaucum, which was a remarkable achievement. But being an unknown, young student, Duchesne was not acknowledged with this discovery, and was prevented from continuing more research due to army research.3 Later similar discoveries were to be met with little attention until the 1920s. In 1928, a British bacteriologist Sir Alexander Fleming was studying the effects of Staphylococci, a genus of Gram-positive bacteria. He hypothesised that the mould, Penicillium notatum, was

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Nucleic acid, DNA replication and Protein Synthesis

Bina NUCLEIC ACUD, DNA REPLICATION AND PROTEIN SYNTHESIS Mohammed Majeed Mohammed Majeed Bina Biology key skills Poodles make more poodles. Sheep make more sheep. Replication is a basic fact of life. All living things make other living things that are to one degree or another duplicates of themselves. What is the mechanism behind all this? The answer lies in a molecule called DNA. In 1869, Friedrich Miescher extracted a substance, which he called nuclein from the nuclei of white blood cells. Nuclein later became known as nucleic acid. Living cells contain two kinds of nucleic acids-ribonucleic acid (RNA) which contains the sugar, ribose and deoxyribonucleic (DNA) which contains the sugar, deoxyribose. Nucleic acids are found in all living things, from the simplest protozoan to the most complex forms of animal and plant life . Two young scientists-James Watson and Francis Crick-finally pieced together the precise structure of DNA. The model proposed by Watson and Crick for the structure of DNA is shaped like a twisted ladder. This type of figure is known as a double helix. The sides of the twisted ladder are made up of alternating units of deoxyribose and phosphate. The rungs of the ladder are composed of paired nitrogen bases. Adenine always pairs with thymine, and guanine always pairs cytosine. The bases are held together by hydrogen bonds. Watson and Crick's

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Discuss the role of feedback in the learning of skills Feedback is the return of information which has been brought about by the result of a process or activity

Discuss the role of feedback in the learning of skills Feedback is the return of information which has been brought about by the result of a process or activity, the aim of it is to maintain or to control this process which in this context refers to a physical activity. In a physical activity, for a movement to progress the athlete needs to be aware of the effectiveness of their performance the athlete receive this information through the form of feedback. There are three loops to this feedback process:- Exteroceptive is feedback which comes from the performer's observation of their performance i.e. in a free kick the ball may not travel to where the performer had hoped, by gaining feedback the athlete is able to identify the problem and correct it. Alternatively the athlete can receive feedback in this way when watching a video of their performance, this allows the athlete to analyse their own performance i.e. to identify whether it is aesthetically pleasing, how the skill could be improved etc. This feedback can also come from other people, specifically coaches who can suggest methods to improve or maintain a skill from what they see. Proprioceptive is the feedback which is provided by the receptors found in muscles and tendons called proprioceptors and the balance sensors which provide information on how a movement 'feels.' When an athlete becomes familiar with a

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Heterosporous Plants

Heterosporous

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