Play It Again Sam Analysis Essay Example for Free

Play It Again Sam Analysis Essay Sam is an excellent production, by far one of Woody Allen’s best movies. It tells the story of Allan Felix, a neurotic New York film critic who is left by his wife, since according to her he is an ‘observer, not a doer’. This devastating event makes him fall into a deep depression; consequentially, he gets corporal aid from his married friends, Linda and Dick. However, this help appears not to be enough, Allan’s love life seems going nowhere until he creates a special connection with Linda, which leads him into her arms. My opinion about this movie being excellent is based on several facts, which can be easily appreciated when watching this extremely controversial film. The word ‘controversial’ should be emphasized when analyzing this movie, considering that the topics discussed in it were not commonly discussed or confronted in the mid nineties, time in which this film was released. This movie is considered polemic due to the obvious critiques towards the American’s daily life, which is achieved by mentioning different subjects such as, dependence. This theme is represented in a different way depending on the character we focus; with Allan, this topic is represented by the deep depression he falls into, which follows him though all the film. When focusing in another character, Linda in this case, her dependence is shown by her pill addiction. Finally Dick, he is a workaholic, his dependence takes him to the point when he starts comparing his love to his wife with an ‘economical investment’. These characters decide to depend on something so it is easier for them to be secure and comfortable, ignoring the problems surrounding them and escaping from reality. Stereotyping is another main theme in this movie. When Dick asks Allan how he liked women, he describes a model type ‘Skinny, blond, good breasts’. This stereotype of perfect women is a consequence of the idol worshiping so characteristic of us, human beings. We all have someone we follow. An actress, singer, model, etc. someone we relate ourselves with or because we want to overcome something we don’t like about ourselves, we always use someone as a reference and Allan is not the exception. Allans character is a Humphrey Bogart-obsessed film writer that has abundant imagination. Bogart himself appears as an apparition to give Allen advices. Allan: I cant do it. How does it look? I invite her over and then come on like a sex degenerate. What am I, a rapist? Bogart: Youre getting carried away. You think too much. Just do it. Allan: Were platonic friends. I cant spoil that by coming on. Shell slap my face. Bogart: Oh, Ive had my face slapped plenty of times. Allan: Yeah, but your glasses dont go flying across the room. The reason why Woody Allen sets the title ‘Play it again, Sam’ is because it is originally a quote from the film Casablanca, and as I already said before the main character is obsessed over this movie (Casablanca) and the main character of it. Not only the apparitions of imaginary characters and dependence on drugs and self unconformity but how music is applied to the film shows how Allan is trying to escape from reality and place himself in a romantic Bogart movie. Every time he has a date, he turns on the music volume really loud so that the atmosphere is more movies like or factionary. We can appreciate this all over the movie and mostly at the end when he quotes the ending of Casablanca. Finally, trying too hard is the last main topic. Allan is always trying too hard for everything, making things tougher for himself and being clumsy. This is a quote from the movie demonstrating what I just stated, Allan: What are you doing Saturday night? Woman: Committing Suicide. Allan: What about Friday night? This character is always trying to fit in, we can appreciate in a scene on the movie the night after his wife leaves him that he goes to a pub and takes a drink but he doesn’t really likes it, he is juts doing what most of the men do trying to be normal. In conclusion, I believe this is a great movie, considering that it is not only hilarious; but it is fascinating how the different elements used by the film director Herbert Ross such as, music, effects, lights and place set; creates a perfect atmosphere for each of the scenes. Also, the actors chosen were all brilliant choices and how every character has its own meaning, contributing a special and unique theme to this classical film. This movie is one of my favorite oldies.

Biology Essays Factors affecting mammal population in the neotropics

Biology Essays Factors affecting mammal population in the neotropics An essay on the factors affecting mammal population in the neotropics and the challenges managing these populations. Introduction The Neotropics includes Mexico, Central America, South America, the Caribbean and Southern Florida and it also hold the greatest amount of standing forests. These wooded wildlands are mosaic in a variety of green that together add up to some 1.37 million acres. Mammals in these areas are affected by several factors which affect their livelihood and sustenance. As a result, any of these species are either being extinct or reduced. Mammals are described as any of a large group of warm-blooded vertebrate animals characterized by having mammary glands in the female, which is used for suckling the young. Other features includes hairs which are very reduced in some species such as whales, a middle ear formed from three small bones (ossicles), a lower jaw consisting of two bones only, seven vertebrae in the neck and no nucleus in the red blood cells. Mammals belong to the class Mammalia. They are divided into three groups. Eutherians (Placental mammals), this is where the young develop inside the mother’s body in the uterus and receives nourishment from the blood of the mother via the placenta. The Marsupials (Pouched mammlas), where the young’s are born at an early stage of development and develop futher in a pouch on the mother’s body where they are attached to and feed from a nipple and the final group being, Monotremes (Egg- laying mammlas), this is where the young hatch from an egg outside the mother’s body and then nourished with milk. The monotremes are the least evolved and have been largely displaced by more sophisticated marsupials and placentals, so they are only a few types surviving platypus and echidna. Placental mammals have spread to all parts of the globe where they have competed with marsupials; they have in general displaced the marsupial types. However, marsupials occupy many specialized niches in South America and especially Australia. There are over 4000 species of mammals, adapted to almost every way of life, with the smallest shrew weighing 2g/0.07oz and the largest the whale up to 140 tons. According to the Red list of endangered species published by the World Conservation Union for 1996, 25% of mammal species population is threatened with extinction. The Red list of endangered species is a scientific assessment of the status of the world’s animal species. Although it carries no legal force this international compilation is seen by many scientist and conservationist as a warning of global decline in the wildlife biodiversity. The report also sates that 24 of the 26 orders of mammalian species are at the brink of extinction globally with an excess of 50% of the neotropical mammalian species. A leading cause of this decline in population is due to habitat degradation and destruction which is mostly due to human population and economic development, such as, over hunting, pollution and deforestation. There is also the introduction of non native species that plays a significant threat to mammalian species survival along side climatic changes. This assignment will discuss the factors affecting mammal population in the neotropics and also I will seek to list the challenges managing these populations. Factors affecting mammals of the neotropics Humans are the chief cause of neotropical mammalian loss. They destroy the plants which provide food and also shelter for the animals and also hunt for them and utilize their meat as food and their skin for clothing. Plants are generally taxonomically diverse and omnipresent. They function as primary producers hence; they are the most critical components in the maintenance of a vibrant functional mammalian population. It provides food for almost all mammals, coverings for numerous organisms, stabilize water sheds functioning and also provide a variety of other critical ecological functions such as stabilizing the earth’s oxygen content and nitrogen fixation which are vital for the animals’ survival. Most of this destruction by humans (a mammal) occurs to clear land for agriculture and cattle grazing, even though much of the forested land is inappropriate for farming or ranching. Cutting down of the plant removes most of the nutrients from the ecosystem, leaving soil tha t will only be able to support intensive agriculture for a couple of seasons. Over the past decade, Large-scale forest fires, timber extraction by local and foreign companies, mining, the building of dams, and population growth have also made significant contributions to forest loss in the neotropics. Population growth and economic expansion have led to the construction of new roads and buildings that both physically and ecologically fragment the forest, reducing its vitality. The now plantless lands or once forested areas are subsequently being used for the construction of homes, and consequently animals are being forced to migrate form these areas resulting in reduction in the species population. Habitat fragmentation could result in the loss and strain on the mammalian population. Some animals can benefit from the fragments of land while others may not. Depending on the size of the island patches large animals like jaguars can find it very difficult to obtain sufficient food for their survival. Many mammals such as manatees, cows, pigs, and sheep just to name a few are hunted and used by humans for food purposes. In addition to be hunted for food purposes some animals are hunted primarily for clothing and ornamental purposes. Wildlife trade also reduces the population or destroys the habitat of many neotropical mammals. Wild life trade is the third largest illegal trade in the world and it has an estimate of $1 billion on the Brazilian market alone. It affects most of the species that are officially listed as endangered species. As it relates to Brazil wildlife animals are officially being held in captivity including the threatened species such as the golden lion tamarin and the capuchin monkeys. Over the years, penalties have been enforced on poachers and people who obtain the wild animals. Mammals that are being taken out of their natural habitat are being trained and used as game animals for exhibition and economical purposes. Neotropical environments are also threatened by intensifying and poorly planned developments. Such development has resulted in ecosystem devastation. Pollution of rivers, beaches and other water beds by industrial, municipal and human waste has resulted in the loss or illness of many aquatic mammals such as dolphins. In the most industrialized country, Brazil, pollution in the area has often resulted in acid rain over the forest remnants. Fires such as campfires and accidental forest fires play a critical role in the depletion of the species. Noise pollution also plays a part in the disturbance of mammals’ population especially underwater noise pollution which is a disturbing problem that is quickly degrading the ocean life. This type of pollution can be described in many ways, simply because the ocean is filled to the brim with loud noises coming from various sources for example, military sonar, used for defensive and research purposes, fishing boats, merchant ships, research vessels, and oil rigs. Some of these noises are as a result of human activity. The increase of noise in the ocean has adverse effects on marine mammals in almost every aspect of their life, one of which is their behaviour. In order to communicate with each other, many species of whales depend on hearing calls from other whales. These calls can easily be hidden behind acoustic masking from sounds in the same frequency ranges. For example, the calls of baleen whales (humpback, blue, fin, and grey whales) are frequencies that range from 20 to 500 Hz. Sonar and even natural sources frequencies of sounds can mask the calls of whales and other marine mammals and significantly alter their natural behaviors. This noise can also cover other behaviors such as dolphin special echolocation skills used for navigational purposes, foraging for food, and communication within the specific group members. You can get expert help with your essays right now. Find out more The building of roads and other building can divide biomes and isolate many animals in the neotropics through the clearing of trees. Road traffic also causes pollution and also kills many of the animals. Many highways and buildings have been built without necessary environmental impact reports, and many are left unfinished, leaving neighboring areas vulnerable to severe erosion, that can have negative outcome on the animals’ survival. Climatic changes can also have impacts on the species population. High environmental temperatures can lessen male fertility by damaging or killing sperm, While, it can also trigger blood flow changes that reduce the flow of blood to the uterine tract, damaging or killing developing embryos in females thus lowering, their fertility rate. All the above factors can have and is having a great impact on the neotropical mammal population. Challenges managing the factors affecting the neotropic mammal population Although neotropical mammals, are faced with many challenges in dealing with their continuous existence, various managing schemes are being put in place to prevent these hazardous impacts to control their population. Conservation projects have being established in selected areas in an attempt to reverse the trend in declining population sizes. These projects play a vital part in the development of ecotourism in almost all parts of the neotropics and also the protection and conservation of various animal species. In terms of ecotourism development, tourists will have to pay to visit areas with interesting natural and cultural features. Conservationists from the various projects can also work along with local communities to educate people about the value of the wildlife in the area, to eliminate illegal hunting and to assist communities in developing farming and logging methods that are habitat and also animal friendly. The implementation of national parks and other private organizations can also play a part in conservation activities that can help to eradicate and protect the neotropical animals who lives are at stake. In addition to the development in ecotourism, the establishment of protected areas can also play a part in protecting the species diversity. Protected areas establishment will tend to have important economic as well as social function in conserving biodiversity. Captive breeding is another managing scheme which can help with this. It focuses on the reproduction of rare animals in captivity. The legal practice of captive breeding increases the population of many endangered species world wide. Species that are being held captive in this way can serve as a demographic and genetic reservoir for the species. Examples of few neotropical mammals held captive are the golden lion tamarin the capuchin monkeys, seals manatees and wildcats such as jaguar. A penalty of a fixed amount should be enforced to the various people of the different regions who practice the illegal capturing and use of the animals in the wild for their own purposes such as exploitation and over hunting. In 1975, the Convention of International Trade in Endangered Species (CITES) treaty prohibited international trade on most wild cats and was dramatically effective in curtailing trade of jaguar skins. In closing it can be noted that a wise approach towards the neotropical regions can be of great importance in the conservation of the animals species diversity. Although many of these approach are being taken by humans (a mammal), much more measures should be put in place try and curb this situation, because they are some heartless people who are still practicing these unlawful activities and should be punished for their heartless actions. With this in place there will be a rich mammalian population not only in the neotropical regions but also other parts of the world. References Lindley, David (1998) Webster’s New World Dictionary of Science, Helicon Publishing Limited Whitmore, T.C. (1998) An Introduction to Tropical Rain Forests, Second Edition Oxford University Press New York www.biodiversityhotspots.org/xp/Hotspots/cerrado/biodiversity.xml date accessed 2008-02-26 http://www.rainforest-alliance.org/aar.cfm?id=conservation date accessed 2008-02-26

Free Native Son Essays: Naturalism and Determinism :: Native Son Essays

Naturalism and Determinism in Native Son "Today Bigger Thomas and that mob are strangers, yet they hate. They hate because they fear, and they fear because they feel that the deepest feelings of their lives are being assaulted and outraged. And they do not know why; they are powerless pawns in a blind play of social forces."   This passage epitomizes for Richard Wright, the most radical effects of criminal racial situation in America. However, perhaps the most important role of this passage is the way in which it embodies Wright's overall philosophy of Naturalism or Social Realism. The naturalist perspective in the passage is evident through the use of the most crucial features of Naturalism. The passage also echoes the most crucial features of Determinism. namely fear, hate and mob mentality. In a critical analysis of this passage there are many single phrases to dissect. One such phrase is, "They hate...." The hatred that is felt by the white mob is a product of their guilt. It is the guilt like that of Mr. Dalton that is so strong that he tries to "undo it in a manner as naà ¯ve as dropping a penny in a blind man's cup."   Wright further speaks of this guilt when Max states, "The Thomas family got poor and the Dalton family got rich. And Mr. Dalton, a decent man, tried to salve his feelings by giving money. But, my friend, gold was not enough! Corpses cannot be bribed! Say to yourself Mr. Dalton, 'I offered my daughter as a burnt sacrifice and it was not enough to push back into it's grave this thing that haunts me.'" This s tatement embodies the very core of social reality of the time, and in essence, Social Realism. "They fear...." What fear is Wright speaking of? Wright speaks of the fear that both the blacks and the whites feel. Bigger's fear and hate is a direct result of the way he sees society. Bigger sees in a garish light the failure of his society. He sees it's cultural and political ideals and promises, and he refuses to accept the compromises that most individuals make for simple self-preservation (as was in Bessie's case.) The white's fear is different. They fear loosing the power and control that they have over the blacks. The whites believe that if they correct the socioeconomic state of the black they will, in essence, be compromising their seat of power. Free Native Son Essays: Naturalism and Determinism :: Native Son Essays Naturalism and Determinism in Native Son "Today Bigger Thomas and that mob are strangers, yet they hate. They hate because they fear, and they fear because they feel that the deepest feelings of their lives are being assaulted and outraged. And they do not know why; they are powerless pawns in a blind play of social forces."   This passage epitomizes for Richard Wright, the most radical effects of criminal racial situation in America. However, perhaps the most important role of this passage is the way in which it embodies Wright's overall philosophy of Naturalism or Social Realism. The naturalist perspective in the passage is evident through the use of the most crucial features of Naturalism. The passage also echoes the most crucial features of Determinism. namely fear, hate and mob mentality. In a critical analysis of this passage there are many single phrases to dissect. One such phrase is, "They hate...." The hatred that is felt by the white mob is a product of their guilt. It is the guilt like that of Mr. Dalton that is so strong that he tries to "undo it in a manner as naà ¯ve as dropping a penny in a blind man's cup."   Wright further speaks of this guilt when Max states, "The Thomas family got poor and the Dalton family got rich. And Mr. Dalton, a decent man, tried to salve his feelings by giving money. But, my friend, gold was not enough! Corpses cannot be bribed! Say to yourself Mr. Dalton, 'I offered my daughter as a burnt sacrifice and it was not enough to push back into it's grave this thing that haunts me.'" This s tatement embodies the very core of social reality of the time, and in essence, Social Realism. "They fear...." What fear is Wright speaking of? Wright speaks of the fear that both the blacks and the whites feel. Bigger's fear and hate is a direct result of the way he sees society. Bigger sees in a garish light the failure of his society. He sees it's cultural and political ideals and promises, and he refuses to accept the compromises that most individuals make for simple self-preservation (as was in Bessie's case.) The white's fear is different. They fear loosing the power and control that they have over the blacks. The whites believe that if they correct the socioeconomic state of the black they will, in essence, be compromising their seat of power.

Lord of the Flies :: essays research papers

Lord of the Flies   Ã‚  Ã‚  Ã‚  Ã‚  Ã¢â‚¬Å"A thing was crawling out the forest. It came darkly, uncertainly. The shrill screaming that rose before the beast was like a pain.† This so-called beast that emerged from the forest was Simon, one of the boys who was stranded on the island. After he emerged from the forest, Simon discovered what the â€Å"pig’s head on a stick† represented, his untimely demise and tribal chaos. This was also when the real Lord of the Flies that was stalking the boys on the island reared its ugly head.   Ã‚  Ã‚  Ã‚  Ã‚  While Simon was concealed in the forest, watching the self-proclaimed â€Å"hunters† kill a sow, he observed them place the head of this pig on a stick as an offering to the â€Å"beast.† After the hunters left, Simon began to see what that the pig’s head represented. It showed that an immense amount of turmoil was going to take place on the island. This turmoil began when Jack started his own little tribe that was comprised of all the hunters and offered anyone free membership. Everyone, except Ralph and Piggy, joined the new clique because Jack claimed that they would always have meat to eat. Ralph and Piggy knew that this was the wrong decision to make because Jack was very immature had no clue how to lead anyone and all he wanted to do was kill.   Ã‚  Ã‚  Ã‚  Ã‚  After the new tribe was formed, they moved themselves to a rock peninsula because they thought it would make a good fort, whereas Ralph and Piggy continued to live at the original place on the beach. Since Piggy and Ralph were now considered outcasts, Jack’s tribe stole Piggy’s glasses one night so that they could have fire. When Ralph and Piggy went to their little fort to get them back, a large boulder was pushed off their fort, killing Piggy and leaving Ralph all alone. Jack then made it his mission to hunt down Ralph and place his head on a stick, just like the pig’s. Jack never did kill Ralph because a British naval vessel showed up to rescue the boys from the island but the beast still resided there.   Ã‚  Ã‚  Ã‚  Ã‚  The beast that stalked the island is maturity. Simon, Ralph, and Piggy realized that the only way to survive was to grow up and try to act like adults. Jack and his hunters, on the other hand, did not want to mature and act like adults.

evilmac Essay on Evil in Shakespeares Richard III and Macbeth

Vision of Evil in Richard III and Macbeth    Shakesperae’s play Macbeth is in some respects a relatively simple play. Like Richard III its’ structure follows a standard conventional form: the rise and fall of a great man. The first part of the play follows Macbeth's rise to power. By 3.1 he has assumed the kingship. The rest of the play follows the disintegration of all he has achieved, a process that culminates with his death and the installment of new king. In that sense, there is very little difference in the structure between Richard III and Macbeth.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   But, of course, they are vastly different plays. The key difference is the psychological portrait of the hero. In Richard III there is an amalgam of different theatrical depictions of evil and that the predominant one was the Vice-Machiavel, the Devil incarnate, who is presented in such a way that we are not encouraged to probe very much into his motivation, his psychological response to events as they unfold, and his disintegration. We do have some clear hints at a possible psychological source for Richard's conduct (the opening soliloquy points to his deformity and his inability to love), but I suggested that these are more symbols of his evil than their cause. This approach to Richard's character allows us to develop in more detail an appreciation for how much the effects of this play depend upon Richard's theatricality, on his outward behaviour (which he invites us to admire in a shared understanding of how clever he is in comparison w ith everyone else), rather than on any inward complexity.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Macbeth is totally different. There is nothing at all theatrical about the presentation of his character. He does not confide in us or seek to e... ...ll always be such people, often among the best and the brightest – politicians, business and community leaders, entertainers and sports figures. So overcoming one particular person is no final triumph of anything. It is a reminder of just how fragile the basic moral assumptions we make about ourselves can be. In that sense, Macbeth, like all great tragedies, is potentially a very emotionally disturbing play. It does not reassure us that the forces of good will always prevail, rather that the powers of darkness are always present, for all our pious hopes and beliefs. Works Cited: Shakespeare, William. Richard III. The Norton Shakespeare. Ed. Stephen Greenblatt. (New York: W.W. Norton and Company, 1997) Shakespeare, William. Macbeth. Literature: An Introduction to Fiction, Poetry, and Drama. Ed. X.J. Kennedy and Dana Gioia. 7th ed. New York: Longman, 1999.

Family Business Essay

Family business are businesses that are created from their founding fathers of that era, if may evolve from small businesses into big enterprises. Family business is playing a very important part in the economy of Malaysia; the reason is that more than half of the Gross Domestic Product of Malaysia is from the family businesses that are conducted in Malaysia. For example The Genting group and The Berjaya group are two of the most famous family businesses that are conducted in Malaysia. The following are the issues and challenges that are faced by family businesses in Malaysia. The first challenge and issue that affects family businesses in Malaysia is succession planning which is choosing the next successor for the business after the current successor retires or passed away. Choosing a successor is one of the biggest challenges and is often faced by family businesses in Malaysia. Choosing a successor is hard because there are many factors that need to be considered before delegating him or her to be the successor of the family business. The first factor is of course the capability of the potential successor, to see whether he or she is up to standard andable to handle the responsibility that is about to be passed onto to see whether they qualify for the position. The second factor is that the potential successor must have certain amount of knowledge about the business and must know every part of operation of the business in details. The potential successor must also have very good management skills and have a good relationship with everyone involved in the business in order to have smoother process when sharing business ideas. The second challenge and issue that affects the family businesses in Malaysia is family disputes which is the harmony between family members and also within the business. The reason why it is one of the challenges and issues is because some of the family members or people involved in the business are always jealous of each other, or they are angry because of the decisions made which they are unfair, which will then results in political issues happening in the business which can greatly affect the outcome of the business, and sometimes it may be serious until it can tear down the whole business. So that is why it is very hard to keep the family and business at harmony all the time. However, if they are able to do so, it will help improve the communications between family members and also people involved in the business so that they can share out their feelings and the conflicts more openly so that the conflict can be solved in a way that will benefit the family and the business. The third challenge and issue that affects the family businesses in Malaysia is professionalism which is capability of keeping the family business up and running for a long term. This is a very hard challenge for all the family businesses out there in Malaysia because it has many factors to look at in order to keep the family business in one piece, because family businesses often faced with conflicts between one another sometimes because of the informal business structure, like there are no roles given formally which then allows everyone can step into each other territory in the business structure which is also known as invading other’s personal workspace. The other reason is because of the non-systematic work which is caused by bad operation control which can greatly impact the operation of the family business. However, if management is in good control and the organizational structure is complete and the objective and goals is the same and shared by everyone, the efficiency of the family business will sure improve a lot. Staff training can also improve the professionalism of the family business. The fourth challenge and issue that affects the family businesses in Malaysia is leadership which is basically the compass for the direction of the family business. It is very hard for family business to have good leadership because it involves leading, involving, and also motivating the people in the family business so that they share the same goal. So, if the leader of the family business is strong, then the chance of the business to succeed will surely be very high. The first thing is that the good leader must have the stamina and the passion to lead. Besides that, the leader must have a wide knowledge of the economy and also the industry itself so that he or she can direct a most beneficial way for the family business to approach and also giving a sense of common purpose. Lastly, the leader must have power to control the people in the family business and tell them what is the plan and what they need to do. The last challenge and issue that affects the family businesses in Malaysi a is fair compensation which also includes fair treatment to the people involved in the family business. The reason why this is a common issue in family business is because that the family members always tend to treat their own family member better and they also make bias decision most of the time. The most common problem is the payment and the salary of the people in family business. People who are the family member often get better pay which then the other people will feel cheated and mistreated at the same time. Then they will feel alienated by the family members of the family business, which will then greatly affect the earning capability of the business. Although there are quite some challenges and issues faced by family business in Malaysia, but if those family businesses can overcome the challenges and issues that are stated above, then their family business will surely be stable and run for a long time. Reference List: 1. http://www.ukm.my/ajag/vol2ch2.pdf 2. http://www.businessnewsdaily.com/862-family-business-challenges.html 3. http://www.freemalaysiatoday.com/category/opinion/2012/02/02/asias-family-businesses-face-new-challenges/ 4. http://familybusiness.about.com/od/managementandoperations/a/commonthreats.htm 5. http://www.isb.edu/FamilyBusiness/File/challengesfacedbyindian.pdf

Plant Responses

PLANT RESPONSES TROPISM is a biological phenomenon, indicating growth or turning movement of a biological organism, usually a plant, in response to an environmental stimulus. In tropisms, this response is dependent on the direction of the species. The word tropism comes from the Greek trope (â€Å"to turn† or â€Å"to change†). Tropisms are usually named for the stimulus involved and may be either positive (towards the stimulus) or negative (away from the stimulus). Phototropism is the growth response of a plant in response to light direction.Different parts of a plant exhibit different reactions to light. Stems exhibit positive phototropism while most roots exhibit negative phototropism. Geotropism is the growth response of a plant in response to gravity. Roots exhibit positive geotropism while stems and leaves exhibit negative geotropism. Hydrotropism is the growth response of a plant to water. Roots exhibit positive hydrotropism. Thigmotropism is the growth response of a plant to physical contact (touch). Plants that cling to physical structures such as walls exhibit positive thigmotropism.Chemotropism is the growth response of a plant to a particular chemical. Roots grow toward useful minerals in the soil but away from acids. PLANT HORMONES Auxins are a class of plant hormones (or plant growth substances) with some morphogen-like characteristics. Auxins have a cardinal role in coordination of many growth and behavioral processes in the plant's life cycle and are essential for plant body development. functions -Stimulates cell elongation -Stimulates cell division in the cambium and, in combination with cytokinins in tissue culture -Stimulates differentiation of phloem and xylem Stimulates root initiation on stem cuttings and lateral root development in tissue culture -Mediates the tropistic response of bending in response to gravity and light -The auxin supply from the apical bud suppresses growth of lateral buds -Delays leaf senescence -Can in hibit or promote (via ethylene stimulation) leaf and fruit abscission -Can induce fruit setting and growth in some plants -Involved in assimilate movement toward auxin possibly by an effect on phloem transport -Delays fruit ripening -Promotes flowering in Bromeliads Stimulates growth of flower parts -Promotes (via ethylene production) femaleness in dioecious flowers -Stimulates the production of ethylene at high concentrations GIBBERILLIN Unlike the classification of auxins which are classified on the basis of function, gibberellins are classified on the basis of structure as well as function. All gibberellins are derived from the ent-gibberellane skeleton. The structure of this skeleton derivative along with the structure of a few of the active gibberellins are shown above.The gibberellins are named GA1†¦. GAn in order of discovery. Gibberellic acid, which was the first gibberellin to be structurally characterised , is GA3. Function – Stimulate stem elongation by stimul ating cell division and elongation. -Stimulates bolting/flowering in response to long days. -Breaks seed dormancy in some plants which require stratification or light to induce germination. -Stimulates enzyme production (a-amylase) in germinating cereal grains for mobilization of seed reserves. -Induces maleness in dioecious flowers (sex expression). Can cause parthenocarpic (seedless) fruit development. -Can delay senescence in leaves and citrus fruits. Abscisic acid is a single compound unlike the auxins, gibberellins, and cytokinins. It was called â€Å"abscisin II† originally because it was thought to play a major role in abscission of fruits. At about the same time another group was calling it â€Å"dormin† because they thought it had a major role in bud dormancy. The name abscisic acid (ABA) was coined by a compromise between the two groups.Though ABA generally is thought to play mostly inhibitory roles, it has many promoting functions as well(Arteca, 1996; Mause th, 1991; Raven, 1992; Salisbury and Ross, 1992). Function -Stimulates the closure of stomata (water stress brings about an increase in ABA synthesis). -Inhibits shoot growth but will not have as much affect on roots or may even promote growth of roots. -Induces seeds to synthesize storage proteins. -Inhibits the affect of gibberellins on stimulating de novo synthesis of a-amylase. -Has some effect on induction and maintanance of dormancy. Induces gene transcription especially for proteinase inhibitors in response to wounding which may explain an apparent role in pathogen defense. Cytokinins are compounds with a structure resembling adenine which promote cell division and have other similar functions to kinetin. Kinetin was the first cytokinin discovered and so named because of the compounds ability to promote cytokinesis (cell division). Though it is a natural compound, It is not made in plants, and is therefore usually considered a â€Å"synthetic† cytokinin (meaning that t he hormone is synthesized somewhere other than in a plant).The most common form of naturally occurring cytokinin in plants today is called zeatin which was isolated from corn (Zea mays). Function -Stimulates cell division. -Stimulates morphogenesis (shoot initiation/bud formation) in tissue culture. -Stimulates the growth of lateral buds-release of apical dominance. -Stimulates leaf expansion resulting from cell enlargement. -May enhance stomatal opening in some species. -Promotes the conversion of etioplasts into chloroplasts via stimulation of chlorophyll synthesis. DIFFERENCE BETWEEN SHORT DAY PLANTSShort-day and long-day plants exhibit a response to photoperiodism, or the changes in light and dark in a twenty-four-hour cycle. Short-day plants form flowers when the days become shorter than a critical length, while long-day plants form flowers when the days become longer than a critical length. Short-day plants bloom in late summer or autumn in middle latitudes. Examples of short- day plants are chrysanthemums, goldenrods, poinsettias, soybeans, and ragweed. Long-day plants bloom in spring and early summer. Some examples of long-day plants are clover, irises, and hollyhocks.Florists and commercial plant growers can adjust the amount of light a plant receives to force it to bloom out of season. A short day plant is a plant that flowers only when it is exposed to light for a short period of time, like in early spring or fall, approximately 12 hours. Chrysanthemums and strawberries are short day plants. A long day plant flowers only when it is exposed to light for a long period of time, like in the summer. Lettuces, spinach, and other different types of wheat are long day palnts. Short- need a lot of night long- need a lot of day.