Briefing Paper Essay Example | Topics and Well Written Essays - 500 words

Briefing Paper - Essay Example Hornby Plc currently has the greatest market opportunity of the toy industry in the upcoming 2012 Christmas season. The firm has to implement a growth strategy this upcoming season to diversify its revenue stream. The company will penetrate ten new consumer markets utilizing an exporting strategy. The firm will implement a passive exporting strategy focused on capitalizing on the season boom that occurs every year on Christmas. The firm will target at least five Latin economies. â€Å"Goldman Sachs forecasts that Brazil and Mexico will be solidly placed within the world’s six largest economies by 2050† (Thecostaricanews, 2012). The Latino toy market has the peculiarity of having two days in which kids receive gifs which are Christmas Day and the 6th of January referred to as Three Wiseman Day. Hornsby will ensure that they have a wide variety of toys by enhancing its supply line of toys. The company is going to increase its number of suppliers to include more high technology toys, bargain toys, and educational toys. Educational toys are great gifts because the toy serves a dual function of entertaining and teaching. These toys help aid the child’s creativity and intellectual growth (Growingtreetoys, 2012). The firm will increase its Chinese supplier of toys. The strategy of increasing suppliers is implemented in order to improve product variety and to increase profitability by lowering acquisition costs. The firm is going to improve its procurement function by acquiring a new information system that will help the firm better access the prices available for toys in the marketplace. The new tactics and strategies at Hornby will only help the firm if the company is able to increase its customer base. The firm needs to pay close attention to its marketing strategies. The firm will reinforce its use of the internet to obtain e-commerce sales. Worldwide e-commerce sales are expected to reach $963 million by the year 2013 (Davis, 2012). The firm should get its

Benjamin Franklin Essay Example | Topics and Well Written Essays - 1000 words

Benjamin Franklin - Essay Example Franklin as a discoverer, he is well known for discovering the lightning rod, bifocals, and the Franklin stove. Franklin also assisted in many civic associations such as the Philadelphia’s fire department and a university. Franklin faced many challenges that he managed to overcome to achieve his goals. For instance, one of the most complicated challenges he experienced was when he appeared before the House of Commons that took place on 13 February 1766 (Isaacson, 2004). The House asked him one hundred and seventy four questions regarding taxation without representation in a limit of only two hours. There were also more series of problems that he faced; his father took him out of school when he was still young so that he could do a job and earn some money, which he was never pleased with that decision because he really liked going to school (Clark, 2004). He also faced another irritating challenge when he was at the age of 17 years for being overweight. He was extremely well-built and skinny because he spent most of his time swimming and trying to be more sporty during the last days of his life, and trying to coach other people on the basics of swimming even when he was seventy years old. Franklin was also mocked, dishonored and was ousted from his position as the postmaster general, and was held responsible by the British government for the Boston Tea Party (Clark, 2004). He was also not so good in academic work and he did not do well in academics more so in mathematics that he was scoring very low grades. Benjamin Franklin helped in major contributions and accomplishments in the history of the Unite States. For example, he was one of the founding Fathers of the U.S., assisted in the drafting of both the declaration of independence and constitution of the U.S., which was the most significant achievement of his life (McCormick, 2008). He came from a poor background and through his efforts and hard works; he became one of the great figures in the American

Recruitment Process. Talent Management. People Equity Essay

Recruitment Process. Talent Management. People Equity - Essay Example Therefore, as a recruiter it is a responsibility to hire those employees who can maintain an ethical culture along with ensuring augmented productivity of the organization. During interview process, it is necessary to judge an individual through various perspectives in terms of qualification, enthusiasm about the given job, whether he/ she can adjust with organizational rules and regulations and the capability of attaining the given targets. When a recruiter selects a fresher as an employee then it is required to be assured that he/she should maintain the morale and culture of the organization, however through a fresher the chances of increasing productivity is quite minimal. Therefore, for a fresher it is necessary to arrange training sessions regarding the work procedure to show the mechanism of achieving the given targets within a specified period of time. Through an effective training session employees must familiarize themselves about the procedure of work and how to increase pr oductivity. Regarding a fresher, an organization should consider that the person does not hamper organizational ethics and culture because they are new in the system. However, when a recruiter hires an experienced person for the job then an impact may be created upon the organizational culture to a certain extent because an experienced person generally knows the basic strategies that can be used to enhance productivity by achieving the targets without any botheration regarding the rules and the regulations. Therefore, when a recruiter selects this type of individuals, he/she should be aware about the attitude and behavior of an experienced person towards the organizational culture. During the interview process, recruiter must discuss properly about the rules and the regulations of the organization with the experienced person. Scenario 2 Talent reservoir for an organization can be assured through proper talent management procedure within the organization which can in turn facilitate to have a pool of skilled employees who can fulfill the company’s goals. In this context, the HR department can play a pivotal role as recruitment and selection procedure is very essential to identify and manage a talent effectively within the organization. Nowadays, talent management is considered as a key ‘buzzword’ in corporate level HR along with training. Talent comprises those individuals who can create a difference in the performance of the organization either through their instant involvement or in the long-term by representing maximum levels of potential. Effective organizations are developed by creating value through people, sales, innovation and customer services among other essential actions. Every organization strives to achieve their business objectives and this struggle mainly involves in supporting, recruiting, training, controlling and reimbursing the entire staff of the system. To support this circumstance, talent management can play a crucial p art for maintaining all these aspects in a proper way. There are certain procedures of talent management which should be taken into consideration (Stewart, 2008). The procedures are: Workforce planning, recruiting On-boarding, performance management Training and performance support Succession planning Compensation as well as benefits Critical skill gap analysis If a recruiter hires a skilled employee according to the job requirement then it can become quite easy for the management to find and nurture the talent within the system which would be fruitful for the organization in terms of attaining long-term profit and ensuring fulfillment of company goals (Bersin, 2006). Scenario 3 Alignment, capability and engagement are the three factors which determine

Does TV Increase Violence among Children and Teenagers Annotated Bibliography

Does TV Increase Violence among Children and Teenagers - Annotated Bibliography Example The document suggest that media companies take responsibilities of making sure the media does not get into the wrong hands of a child who should not be viewing the media. The document uses statistics strongly to prove that violence is not related to media such as violence on Television. The statistics show that as violence in media becomes more popular, homicide rates go down. Video Games are a big factor for the way violence is portrayed in media. The video game Grand Theft Auto San Andreas is profiled in the document. The video game shows scenes of violence, sexuality, drug use and even racial comments. The document seems to argument strongly that violent media does not influence violent behavior in children and teen youth. There are mainly statistics that favor the chosen argument. The article stresses the need to protect children and teens from weapons and other violent objects. Many media sources claim to market their products to an age group that is appropriate for the game. Th e arguments presented in the document are by far favorable to the fact that violent media is not subject to children, but many can argue the fact. Â  Anonymous. "Is exposure to media violence a public-health risk?." Lancet 9619(2008):1137. eLibrary. Web. 17 Feb. 2011. This article focuses on the danger of violent images and games. Some games show constant violence. The violence shown is a harmful exposure to children and teens. Children and young teens can be traumatized by the images of killing and violence. It is obvious that the article is suggesting that there is some sort of a regulation put on the violence that is portrayed in the media. The need for a regulation is important to minimize the amount of violence young children see. The article focuses on the importance that the television and the internet can give educational material. Aside from being able to provide educational material, there are also dangerous exposures to violent images and events. The images that are able to be viewed on the internet can have devastating affects on a child. The focus on this is to explain how important it is to regulate what children and teens are able to view in the media. The exposure is not just a risk for children and teens. The general public is at risk for health issues from all of these violent images. The article is from the United Kingdom and often references the United States. This reference to the United States explains how the violence is highly publicized more than in other countries. The article is summed up by stating that there really is no way to place blame on a certain violent media. However, it is suggested that more studies need to be performed to link violent media with violent behavior. MICHAEL PAUL WILLIAMS. "DANGEROUS MESSAGES? MEDIA VIOLENCE ABOUNDS; SO DOES DEBATE ON ITS EFFECTS." Richmond Times-Dispatch. 13 Oct. 1994: A-1. eLibrary. Web. 17 Feb. 2011. The facts recognized in the document are quite alarming. Facts show that the average chi ld may witness 8,000- 100,000 murders just from watching television. For many that amount is way too much and shows that there is a large need for change. These facts do not also factor in other media such as games and the internet. The harmful effects that these images have on children can change the way the children act dramatically. The debate also expresses the type of children that are likely going to be viewing the violent media. It is stated that children

Languages and Evolution Research Proposal Example | Topics and Well Written Essays - 1000 words

Languages and Evolution - Research Proposal Example A report in the telegraph by Hayley Dixon could perhaps contextualize what I want to achieve. The report stated the widely recognized principle that humans especially children learn new words based from what they hear others use them in conversations. Dixon revealed that experts are now thinking the capability to learn language and acquire new vocabulary may be severely hampered as children increasingly learn through devices such as Ipads. Would children exposed to these technological devices create new vocabularies by imitating sounds from them? I intend to support my position in this mini-research through several arguments. First, I would like to explain and establish the role of vocal imitation in human language development as well as its genetic and biological explanations. Why is this crucial in the origin of our language? I hope to draw a parallel between this area and a potential of radical language change in the future through vocal imitation. I will also support my argument with an analysis of new vocabularies based on vocal imitations. For example, there are the cases of untz, wub and beep. These are new words derived from the human imitation of sounds. For further support, I could also discuss in this context the incidence of â€Å"mesofact† or the way meaning changes for words over time Finally, I would like to devote an important part of my work to the links between vocal imitation, adaptation, human sociality and their role in the future of human language. I would like to confine this within a discourse using technology as a control point. The technology variable is accepted to be increasingly eroding our oral traditions, specifically; the passing of knowledge with the now limited opportunity to hear wide range of words (Hayley). I will answer how - with our new-found incapability to hear and learn new words - could vocal imitation fill the gap

The Greek God Zeus Essay Example for Free

The Greek God Zeus Essay In Greek mythology, Zeus has the most prominent name among all the gods and goddesses. This is because he is the most powerful and formidable of all the deities. From the beginning, legend had established his power since he overthrown his own father to become the leader of the Greek gods and goddesses. Zeus was also notorious for his numerous affairs with women and the countless children produced from these affairs. In Greek literature, he was shown to be fierce, vengeful and pitiful of mortals. However, the authority of Zeus is not absolute or unlimited. He is prone to deceit and trickery. Zeus is both a powerful god and a flawed revered entity, which makes him one of the most interesting personalities in Greek mythology. Before the life of Zeus can be discussed, it is important to discuss the origins of Greek mythology. This is because the origin of Zeus can only be understood from the context of the beginnings of Greek mythology. According to Hesoid, prior to the existence of all things, there was initially Chaos (Rose, 1991). The existence of Chaos was considered the beginning of all things, as it was the existence from which other beings were derived. Chaos gave birth to other beings. These were Night, Darkness (also known as Erebos), Love (also referred to as Eros), Tartaros and Earth. Night and Darkness were responsible for the creation of Day and Sky (also called as Aither). Meanwhile, Earth created the Sea (or Pontos), the Mountains and Heaven on its own (Rose, 1991). The account of Hesoid continued with the union of Heaven and Earth (Rose, 1991). Heaven, that which is also referred to as Uranos, is not really considered a god. On the contrary, Earth (sometimes called Gaia) is truly considered as a goddess. It was said that this unlikely couple produced several offspring. These were â€Å"Okeanos and his eddies, Koios and Krios, Hyperion and Iapetos, Theia and Rhea, Themis and Mnemosyne, Phoibe and Tethys† (Rose, 1991, p. 15). Kronos was the last offspring. He was the most frightful of all children, for he harbored hatred towards his father. Eventually, the family was torn apart by conflict. Heaven became overwhelmed by jealousy towards his children that he forced them all into Earth’s body. When Earth could no longer deal with the suffering, she asked her children to punish their father for revenge. Only Kronos answered his mother’s call; with a sickle, he castrated his father (Rose, 1991). Collectively, the children of Heaven and Earth are called the Titans (Rose, 1991). The Titans are also known as the Elder Gods (Hamilton, 1969). Among the Titans, six composed a different group (Rose, 1991). These include Iapetos, Okeanos, Kronos and their respective wives, Themis, Tethys and Rhea. The most significant couple in this group is Kronos and Rhea, as they were the parents of Zeus. According to legend, Heaven and Earth predicted that one of Kronos’ children would unseat him from power. Kronos was alarmed by the warning; as a result, he swallowed each of his children the moment they were born. Rhea disapproved of Kronos’ actions, so when she gave birth to her youngest, Zeus, she decided to hide him from his father. Rather than give the child, Rhea handed to Kronos a rock clothed like a newborn infant. The prediction of Heaven and Earth came true; when Zeus grew up, he became opposed to his father. While Rhea plotted to trick Kronos into throwing up his children, Zeus came to Tartaros to set free Kronos’ brethren who were jailed there. Cyclops was one of those who were saved, and he provided Zeus with lightning and thunder as gifts in exchange for their freedom. Eventually, the conflict between Kronos and Zeus intensified into a full-blown battle between father and son. The rest of the brethren, including Hekatoncheires and Briareos, were on the side of Zeus. Even Styx and her children proved to be Zeus’ allies. It was said that the battle lasted for a decade. Zeus and his supporters fought from Mount. Olympus, while Kronos and most of the Titans established their post from Mount Orthrys. Themis and Prometheus were the only Titans who did not participate in Kronos’ fight. The battle between the immortals disturbed both the earth and Tartaros; eventually, Zeus emerged as the victor, due to his thunderbolts and stone showers caused by Hekatoncheires. Kronos and his allies were kept in a prison located in Tartaros, with Hekatoncheires serving as the prison guard. The victory of Zeus against Kronos made him the leader among the gods and forced the Titans into lower positions (Rose, 1991). The origin of Zeus is uncertain, as the details of his birth vary according to different sources. Two stories state different locations as the birthplace of Zeus. One story stated that Zeus was born in Crete, while another claimed that the god was born in Arkadia (Rose, 1991). According to the tales that do not establish Crete as his birthplace, Zeus was brought to Crete and was concealed in a cave at Lyktos. Meanwhile, the Cretan legend claimed that Zeus was born in a cave located in either Mount Dikte or Mount Ide. In this cave, Zeus was cared for by local gods and goddesses. It was said that Zeus did not go hungry as a goat named Amaltheia brought him food. The bees also provided Zeus with their honey. It was also said that his cries were inaudible due to the loud war-dance performed by the Kuretes (Rose, 1991). There were various objects closely associated with Zeus. Two of the most prominent objects are the thunderbolt and the aegis (Rose, 1991). The thunderbolt was the god’s destructive weapon; its effect was similar to that of a sharp and powerful missile. Greek art represented the thunderbolt of Zeus as accompanied by flashes of lightning; sometimes, it was also depicted as having wings. As for the aegis, it was the god’s breastplate. It was illustrated by various authors as either a garment or a shield. In a mere mortal, the aegis may seem like an ordinary armor. However, in the hands of Zeus, the aegis served a mighty weapon with magical abilities. According to legend, whenever the aegis was waved at a foe, this individual will be overwhelmed with fright. If the origins of the aegis will be traced, one would find that it is simply a cloak created from the hide of a goat with the hairs still in it. To an ordinary human, the aegis is known for defensive purposes, especially against the weather and the attacks of the enemy. Nonetheless, the aegis is worn by Zeus is filled with his mana, or his deific force (Rose, 1991). Aside from the thunderbolt and the aegis, there were other things attributed to Zeus. The eagle is considered as the god’s bird of choice, while the oak tree was his favorite (Hamilton, 1969). The oracle of Zeus is situated in Dodona, where oak trees were abundant. It was established that the will of Zeus was shown by the movement of the oak leaves, which was later interpreted by the priests (Hamilton, 1969). Zeus belonged to the 12 Olympian gods who reigned after the downfall of the Titans (Hamilton, 1969). He served as the head of this family of divine beings. The group included the siblings of Zeus: his brothers Poseidon and Hades, as well as his sisters Hestia and Hera. The 12 divinities also included the children of Zeus, including Ares, Athena, Apollo, Aphrodite, Hermes and Artemis. Hephaestus was the twelfth god in the group. After Zeus dethroned Kronos, he sought to distribute the universe among his brothers and himself (Rose, 1991). The sea became the official territory of Poseidon, while Hades became the ruler of the underworld. In the division of the universe, Zeus emerged as the mightiest among the three (Hamilton, 1969). He was called various names, such as the â€Å"Rain-god, the Cloud-gatherer and the Lord of the Sky† (Hamilton, 1969, p. 27). In fact, Zeus was more powerful than all the gods and goddesses combined (Hamilton, 1969). Despite Zeus’ status, there were territories which were not under his reign. The three gods agreed that Mount Olympus and the earth would be considered as common ground. It is important to note that the sisters were not included in the distribution of the universe (Rose, 1991). This exclusion was apparently due to the rules of ancient Greek law. After he defeated his father, Zeus had another objective: to search for a wife. He was soon married, but he was also involved in affairs with various women. The marriage of Zeus to Hera is most notable in Greek mythology, though it was suggested that this was not the only marriage Zeus was involved with. According to Homer, Hera was Zeus’ first choice for a wife, as their romance began prior to the defeat of Kronos (Rose, 1991). Ares and Hephaestus, the God of War and the God of Fire respectively, were the children from their union (Hamilton, 1969). However, several accounts stated that Hephaestus was the son of Hera alone. The divine marriage proved to be shaky, due Zeus’ infidelity. The supreme deity was often depicted as a womanizer, as he had this habit of falling in love with many women. His extramarital affairs were countless and often produced children, mortal and immortal alike. It was said that Zeus had to resort to all sorts of trickery to conceal his unfaithfulness, just as he had used beguilement as a means to lure women. However, Hera usually discovered about these affairs. Several accounts of Hera showed that she was mainly concerned with chastising the other females in Zeus’ life. She punished all those whom Zeus fell in love with, though they only submitted to him because of force or trickery. Regardless of their situation, Hera remained filled with hatred and she also punished their children (Hamilton, 1969). Some sources suggest that Zeus was involved in other marriages. Prior to his union with Hera, he was married to Themis, who was one of the Titans (Rose, 1991). This marriage resulted in the birth of the Seasons, as well as the Moirai. After Themis, Zeus was involved with Eurynome. According to Hesoid, she was an offsping of Okeanos and Tethys. The union between Zeus and Eurynome produced Charites, better known in the English language as Graces, based on its Latin origins. The Graces consisted of Aglaia, Euphrosyne and Thalia; they were also known as Splendor, Mirth and Good Cheer respectively (Hamilton, 1969). In most accounts, the Graces were not considered as different entities; they were often depicted as a trinity of beauty and grace. Meanwhile, Themis was not the only Titaness whom Zeus married (Rose, 1991). Zeus also married Mnemosyne, and their union produced the nine Muses. This union was said to have occurred after Zeus’ relationship with Demeter (Rose, 1991). Initially, the Muses were similar to the Graces in the sense they were not distinctly identified from one another (Hamilton, 1969). Eventually, the Muses were distinguished to each other according to their respective fields. Calliope was the Muse of epic poetry, Clio of history, Erato of love poetry, Euterpe of lyric poetry, Polyhymnia of the songs for the deities, Thalia of comedy and Terpsichore of dance (Hamilton, 1969). A significant relationship is the union between Zeus and Demeter (Rose, 1991). The offspring of this marriage was Kore, who is better known as Persephone. According to an Orphic account, Zeus was also in love with his own daughter. He assumed the shape of a dragon or snake to mate with her. Their union produced a son named Zagreus, who was later killed by the Titans based on Hera’s orders. However, this account is rather obscure; the story is contrary to the tradition of Greek mythology which indicates that Persephone was married to Hades, the brother of Zeus (Rose, 1991). Some of the deities included in the 12 Olympians were children of Zeus from his affairs with other women. Apollo is recognized as the God of Truth and Light (Hamilton, 1969). His twin, Artemis, is known to be a brave huntswoman. Both deities were the children of Zeus from his relationship with Leto. Hermes, who is known as the Messenger of Zeus, was the offspring of the supreme god and Maia, the daughter of Atlas. Aphrodite, the Goddess of Beauty and Love, was the offspring of Zeus and Dione according to the Homer’s The Iliad. Nevertheless, another account claimed that Aphrodite came from foam in the sea (Hamilton, 1969). The aforementioned gods and goddesses are only some of the identified children of Zeus. Zeus is known to be the mighty Greek god who had multiple romantic affairs. However, his other attributes were best illustrated in both The Iliad and The Odyssey by Homer. In these epics, the characteristics of the king of the Greek gods are exposed to the reader. While the stories present the extent of his power and personality, these also reveal his limitations and flaws. For instance, it is already a well-known fact that Zeus is supreme and powerful enough to overthrow Kronos. In Book VIII of The Iliad, he asserted that power by reminding the other gods and goddesses that he is the greatest of them all (Hamilton, 1969). The war between the Greeks and the Trojans had forced the deities to take sides and intervene with the mortal conflict. However, in a gathering in Mount Olympus, Zeus warned the other deities against interfering in the war. He reminded them that even in a tug-of-war between him and the others, he would still win. Homer wrote, â€Å"Fasten a rope of gold to heaven and lay hold, every god and goddess. You could not drag down Zeus. But if I wished to drag you down, then I would† (as cited in Hamilton, 1969, p. 27). Zeus was indeed the strongest among all Greek gods. Despite being the mightiest among all the deities, Zeus was depicted as a god whose will was not absolute. This was because his stand towards the war and divine intervention constantly shifted. When The Iliad began, Zeus wanted to have little or no involvement in the Trojan War. When Aphrodite became injured as a result of her involvement in the mortal battle, Zeus instructed her to stay way (Hamilton, 1969). In a similar instance, when Diomedes injured Ares, Zeus was more considerate to the former because he found the latter too impulsive. Also, there was a time in the epic when Hera and Athena wanted to participate in the war and Zeus was forced to threaten them just to prevent them from meddling. At one point, Zeus even seemed to want an end to the intensified conflict; when Paris disappeared from his duel with Menelaus, he suggested that the war should end because Menelaus was technically the winner (Hamilton, 1969). However, it is important to note that Zeus was already involved with the war early on in the epic. The problem with Agamemnon forced Achilles to seek his mother’s help in asking for Zeus’ intervention (Hamilton, 1969). As a favor to her son, Thetis did ask Zeus for the temporary victory of the Trojans just so Achilles can prove to the Greeks that they are ineffective in battle without him. While he insisted to the other gods and goddesses that they must not intervene, he himself was a divine participant in the war. He listened to the plea of Thetis and soon enough, he tricked Agamemnon through a dream. In Book XI, Zeus had informed Hector that he will become victorious after Agamemnon gets injured in battle. Zeus was also shown to provide omens to the mortal participants of the war. In Book XII, Zeus sent an eagle flying with a snake in its claws; later on, the eagle dropped the snake when it was bitten. This proved to be a bad omen which was ignored by Hector. Later on in the epic, Zeus did allow the other deities to meddle in the war. The divine intervention in the war even caused the gods and goddesses themselves to be at war with each other. Instead of being a participant, Zeus was merely a spectator in the divine squabble (Hamilton, 1969). The epics of Homer also depicted Zeus as a god of mercy. Whenever a mortal is placed in an appropriate situation, the powerful god took pity on them. After Achilles killed Hector in The Iliad, he continually dragged his enemy’s corpse (Hamilton, 1969). Zeus and the rest of the gods were not happy with this. Zeus was forced to approach Thetis to put a stop to this unfortunate situation. He asked the deity to talk to her son. In The Odyssey, Odysseus had not found his way home for two decades. For a time, he stayed in an island with the deity Calypso. Calypso refused to let him go and eventually became a prisoner of the island. Zeus knew Odysseus did not deserve this fate and he sought the cooperation of the gods to aid the mortal on his way home. Zeus asked Hermes to travel to the island and convince Calypso to set Odysseus free. Because no one can refuse the command of Zeus, Calypso was forced to do as the god asked (Hamilton, 1969). In The Odyssey, Zeus was also shown to be capable of wrath and vengeance. The supreme god was portrayed as having livestock in his possession (Rose, 1991). On the island of Thrinakie, some of Odysseus’ companions had killed some cattle and sheep to address their hunger. What these men did not know was that those animals were owned by the supreme god himself. Zeus punished these me by sinking their ship. However, he spared Odysseus from drowning (Rose, 1991). Zeus may be presented as powerful, merciful and vengeful god, but the leader of the Greek gods also has his share of imperfections. Zeus is devoid of omnipotence (Hamilton, 1969). He is a powerful god but his power is not unlimited. In addition, Zeus is not omnipresent either. His limitations as a god allowed other deities to deceive him and take advantage of his weaknesses. Because Zeus was not omnipresent, Poseidon took advantage of this limitation to further his cause as proven in The Iliad. Zeus had demanded that the other gods and goddesses should not be involved in the war. In Book XIII, Zeus was busy and was not able to follow the events in the war. In his brother’s absence, Poseidon helped the Greeks aboard his underwater chariot. Despite his brother’s warning, Poseidon went to the battle in disguise to inspire the Greeks (Hamilton, 1969). Hera also took advantage of Zeus’ limitations. The goddess had been against the Trojans from the start, since Paris chose Aphrodite as the most beautiful goddess. From her post in Mount Olympus, Hera was overjoyed with the participation of Poseidon in the war (Hamilton, 1969). She wanted to guarantee that Zeus will not see them interfering in the affairs of the mortals. Zeus was busy in Mount Ida, so he was unable to prevent the other deities from participating in the war. Hera planned to distract Zeus so the other deities can continue their interference without being caught. She enlisted the help of both Aphrodite and Sleep to succeed in her plan. First, she prepared herself in her plot to seduce her husband; she bathed, wore perfume and got dressed. Aphrodite assisted Hera and made her so beautiful that Zeus would not be able to resist her. Then, Hera asked Sleep to visit Zeus. She made her way to Mount Ida and wished to greet Zeus first with flattery and lies. However, Zeus became so overwhelmed by her beauty that he immediately asked her to lay with him. Hera did not want Zeus to see what was happening to the war, so she insisted that they should go to her chamber underwater to avoid the being seen. Zeus refused. After they made love, Zeus fell into a slumber due to Sleep. With Zeus in deep sleep, Poseidon continued with his interference. When Zeus woke up, he realized what happened and reprimanded Hera (Hamilton, 1969). The case with Poseidon and Hera showed how limited Zeus’ power was, even if he was the most powerful god in Greek mythology. His brother Poseidon had undermined his authority when he intervened with the war despite his orders. His own wife Hera was capable of deceiving him, who was supposed to be the mightiest of them all. With the use of trickery, Zeus came under the control of deities more inferior to him. In the aforementioned incident, his love and lust for women proved to be his downfall. He was easily distracted by the physical appearance that he became unmindful of what was actually happening with the mortals. Hence, Zeus was a powerful god but not a perfect one. The limitations of his power allowed other gods and goddesses to deceive him. The reputation of Zeus as the most supreme among all Greek gods and goddesses is justified. He defeated his father Kronos to become the most powerful among all deities. He controlled the Titans and put them under their control. Whenever he was crossed, he sought revenge and severely punished those who had earned his wrath. Meanwhile, he took pity of those who deserved his mercy. Nonetheless, the supremacy of Zeus was not an assurance of his perfection. Zeus was also flawed like the mortals he governed. One of his weaknesses was his love of women, which resulted in many relationships and children. His will was not fixed; he constantly changed his mind. He was not a god of omnipresence or omniscience; this limitation caused him to be a victim of beguilement. Zeus proved to be the most interesting among all Greek gods. While he was mighty and formidable, he was also weak and imperfect. References Hamilton, E. (1969). Mythology: Timeless Tales of Gods and Heroes. New York: Mentor. Rose, H. J. (1991). A Handbook of Greek Mythology. New York: Routledge.

Difference Between Prokaryotic and Eukaryotic Transcription

Difference Between Prokaryotic and Eukaryotic Transcription SUMMARY Biosynthesis of proteins is under direct control of DNA in most cases or else under the control of genetic RNA where DNA is absent. Information for structure of a polypeptide is stored in a polynucleotide chain (Gupta, 2007). Sequences of bases in a particular segment of a polypeptide chain will determine the sequence of amino acids in a particular polypeptide (Gupta, 2007). The relationship popularly known as central dogma explains how protein synthesis is controlled by nucleic acids. There are two major steps involved in protein synthesis (1) transcription and (2) Translation. Transcription involves transfer of genetic information from DNA to mRNA and Translation involves translation of language of nucleic acids in to that of proteins (Gupta, 2007). Transcription will be discussed in detail in the present topic. TEXT Transcription is the synthesis of RNA which carries the genetic information present in DNA (Fig. 1). The DNA is double stranded and can theoretically code for two separate RNA molecules (Jain, 2000). However, it has been found that only one of the two strands of the gene is transcribed (Jain, 2000). Only in a few exceptional cases both strands are transcribed. This is possible because the promoter is asymmetrical and unidirectional (Jain, 2000). The DNA strand which have a sequence homology with the RNA is known as the coding strand. The second strand which is complementary to RNA and serves as the template for RNA synthesis is known as the non-coding strand. It is therefore, a misnomenclature, as it is the non-coding strand which is in fact transcribed to form the primary transcript (Jain, 2000). Transcription in prokaryotes The principal enzyme involved in transcription is the DNA dependent RNA polymerase (commonly called as RNA pol). To understand the transcription, it is necessary to learn more about the RNA polymerase. The bacterial RNA polymerase consists of five polypeptide chains including two chains of ÃŽ ± (alpha) polypeptide and one chain each of ÃŽ ² (beta) and ÃŽ ²ÃƒÅ Ã‚ ¹ (beta dash) and ÏÆ' (sigma) polypeptides (Fig.). The RNA polymerase molecule thus can be represented as ÃŽ ±2ÃŽ ²ÃŽ ²ÃƒÅ Ã‚ ¹ÃÆ', in which the attachment of sigma (ÏÆ') factor is not very firm, so that the core enzyme (ÃŽ ±2ÃŽ ²ÃŽ ²ÃƒÅ Ã‚ ¹) can be easily isolated. The size and function of the prokaryotic RNA polymerase is given in table 1. The active sites of core enzyme are shown in fig. (). Once RNA synthesis is initiated, ÏÆ' dissociates after RNA is 8-9 bases long and then the core enzyme brings about elongation of mRNA. The dissociated sigma factor may again combine with core enzyme to form RNA polymerase holoenzyme (Fig,..). Events in transcription The entire process of transcription can be divided in to following steps: (1) Template recognition (2) Initiation (3) Elongation and (4) Termination Template recognition The promoter directs the RNA polymerase to recognize the correct region of the gene and to bind at this site. The -35 region serves this function and is recognized by the enzyme. The size of the RNA polymerase is such that about 60 nucleotides in the gene are involved in binding of the enzyme to the template. Sigma factor plays an important role in specific binding of the enzyme with the template (Jain, 2000). The core enzyme without the sigma factor can bind to DNA but the binding is not promoter specific. The sigma factor is thus necessary for the formation of promoter-enzyme complex. The binding of RNA polymerase to a site other than the promoter is generally referred as loose binding. In presence of sigma factor, the affinity for loose binding is reduced while the affinity for specific binding is increased (Jain, 2000). Thus the chances of only the specific binding taking place are enhanced many fold in presence of sigma factor (Jain, 2000). Initiation and elongation of RNA synthesis in prokaryotes RNA synthesis by RNA polymerase proceeds in four steps: (i) the holoenzyme first binds at the promoter site, forming the closed promoter complex in which DNA remains double helicle, (ii) the closed complex isomerizes and causes unwinding and separation of DNA strands to form open (binary) promoter complex, (iii) after unwinding only one of the two strands is copied; this is achieved by incorporation of nucleotides, initially without movement of enzyme leading to the formation of RNA chain, up to 9 bases in length. During the incorporation of these 9 bases, at every step, there is a possibility for the release of this small RNA chain, a process described as abortive initiation (Gupta, 2007). A cycle of abortive initiation usually occurs generating a series of short (2-9 base) oligonucleotides, before initiation is usually successful. (iv) Once initiation succeeds, the sigma factor of RNA polymerase dissociates. (v) the dissociation of sigma factor marks the entry of NusA protein, whic h helps elongation, and promotes pausing and termination at specific sites. Core enzyme now undergoes a major conformational rearrangement and a stable ternary elongation complex is formed. This complex moves along DNA, synthesizing RNA all along its path at a rate of about 40 bases per second at 370C (Gupta, 2007). Elongation of RNA transcript continues till an unstable termination complex is formed (Gupta, 2007). Termination The termination of mRNA chain in prokaryotes is brought about by certain termination signals on DNA. These DNA sequences providing termination signals are called terminators (Gupta, 2007). Once the enzyme hits the terminator, it falls off the template and the transcription stops. The termination signals whenever found on DNA can be of two types: (i) Rho (Ï ) dependent termination and (ii) Rho (Ï ) independent termination. (i) Rho (Ï ) dependent termination: The termination factor (Ï ) participates in this type of termination (Jain, 2000). Rho (Ï ) is a 46 KD protein and its active form is a hexamer, having a total mass of 275 KD. It binds to growing RNA chain and moves along the RNA. Once rho catches the RNA polymerase, it results in chain termination. The question arises how?. It has been found that once RNA polymerase hits the terminator sequences, it pauses for a short time. During this period the rho factor reaches the RNA polymerase and causes it to fall off the template. Once RNA polymerase is detached, the RNA chain also comes off and the transcription terminates (Fig). (i) Rho (Ï ) independent termination: In some genes, there is a definite region of intrinsic sequences which causes the termination of RNA chain. This includes two G:C rich stretches at the end of RNA transcript which are complementary to each other. These form a 7-20 bp intra-molecular hairpin structure. Further this region is followed by a small stretch of U residues which form relatively weak interaction with dA residues of the gene (Fig..). such a structure is highly unstable thermodynamically and causes the displacement of newly synthesized RNA from the DNA template. Once the RNA is detached, the RNA polymerase falls off and the termination of transcription occurs. This type of termination provides an interesting example where the structure of RNA itself can cause its own termination from the DNA chain. Transcription in Eukaryotes The eukaryotes have more than one type of RNA polymerase. Based on the activity to ÃŽ ±-aminitin, an antibiotic which inhibits mRNA synthesis, three classes of RNA polymerases have been identified which are involved in the transcription of different class of eukaryotic genes. There properties are given in table 2. The eukaryotic RNA polymerases are large molecules of ˃500KD in size. It has two large subunits of -200KD and -140KD, respectively. The 200 KD subunit is similar to ÃŽ ²ÃƒÅ Ã‚ ¹ subunit of E. coli of RNA polymerase and have similar function (the template binding). Besides these two proteins it also has upto 10 different small subunits. A subunit of Pol II, which has similarity with one of the subunits present in Pol I and also in Pol III, is similar to the ÃŽ ±-subunit of E. coli enzyme and helps in the enzyme assembly. Besides the RNA polymerase, a number of other transcription factors are also needed for the transcription. Promoter sites for Initiation of transcription Promoters for RNA polymerase I could not be initially studied since all genes for rRNA were similar. Promoters for RNA polymerase III, on the other hand, had some unusual downstream promoters. However for RNA polymerase II, several hundred eukaryotic genes have now been sequenced and their promoters studied revealing some general features in three regions located at start point, centred at sited lying between -25 bp and -100 bp. The least effective of these three regions is the TATA or Hogness box (7 bp long) located 20bp upstream to the start point. The TATA box is surrounded by G-C rich sequences and is comparable to pribnow box of prokaryotes. Further upstream is another sequence called CAAT box, which being necessary for initiation, is conserved in some promoters (ÃŽ ² globin gene), but is not necessary in some other genes. This sequence lies between -70 and -80 bp. Another sequence called GC box (GGGC GG) is found in one or more copies at -60 or -100 bp upstream in any orientation in several genes. It has been shown that CAAT and GC boxes determine the efficiency of transcription, while TATA box aligns RNA polymerase at proper site, with the help of TFIID and other transcription factors (Gupta, 2007). Initiation In eukaryotes the initiation is more complex. It involves a number of specific transcription factors. The process has been followed for the Pol II action resulting in the synthesis of mRNA. The process is essentially similar for Pol I and Pol III. For initiation, it requires, a number of trans acting factors along with the RNA polymerase. The trans acting factors, which are the product of various regulatory genes, bind to either DNA or to each other or to RNA polymerase. They can also bind in various combinations. All the transcription factors involved with Pol II are called TF II. First the factor TF IID binds to TATA box (-15 to -21 region) covering about 25 nucleotides within the -17 to -42 region. Now factor TF IIA associates itself to the complex, further extending the protected region towards upstream, upto the -55 to -80 region. On the other hand TF IIB associates itself protecting the region at -10 to +10. It binds to two strands in a non-symmetrical manner. This complex prep ares the stage for binding of RNA polymerase II which covers up to +15 region on template strand and 5 extra nucleotides (up to +20) on the non-template strand. Finally TF IIE joins, extending the protection upto +30 region. Once the entire complex has been assembled, the incorporation of first nucleotide takes place. Transcription factors and elongation of RNA chains in eukaryotes Certain accessory proteins of transcription, called the elongation factors enhance the overall activity of RNA polymerase II, leading to increase in elongation rate. Atleast two such proteins (transcription factors) are known (i) the transcription factor TFIIF accelerates RNA chain growth relatively uniformly, in concert with RNA polymerase II or pol II, (ii) transcription factor TFIIS (also called SII) helps elongation of RNA chain, by relieving the obstructions in the path of such elongation. TFIIS is known to function by first causing hydrolytic cleavage at 3Ê ¹ end of RNA chain, which are stuck and can not elongate. Thus RNA polymerase moves backwards (hydrolytic cleavage) under the direction of TFIIS before it moves forwards through the block to elongation (fig.) (Gupta, 2007). Termination of RNA synthesis in eukaryotes In eukaryotes, the actual termination of RNA polymerase II activity during termination may take place through termination sites similar to those found in prokaryotes (the nature of individual termination sites is not known). But these termination sites are believed to be present away (sometimes up to one kilobase away) from the site of 3Ê ¹ end of mRNA. Obviously 3Ê ¹ end of mRNA will be generated due to post-transcriptional cleavage. This cleavage, at the end, is believed to be achieved by what is popularly called snurp (small nucleur RNA-protein complex). Snurp used for post-transcription cleavage has not been identified so far but is believed to be certainly different than the U1 snurp, which is believed to be involved in intron splicing in split genes. Moreover, a sequence 5Ê ¹ AAUAAA 3Ê ¹ has been found just on the 5Ê ¹ side of poly(A) addition site in several eukaryotic mRNAs. The poly(A) tail is added to 3Ê ¹ end of eukaryotic mRNA after processin g of precursor mRNA. The sequence 5Ê ¹ AAUAAA 3Ê ¹ in mRNA 3Ê ¹ end seems to be common in eukaryotic mRNA and mutation in this sequence cause elongation of mRNA. This will suggest that this sequence contains the signal for endonucleolytic post-transcriptional cleavage. This sequence therefore, is not involved in the termination of the synthesis of mRNA, but helps in generating 3Ê ¹ end later through endonuclease cleavage, in which snurp helps in an unknown manner. FAQs Q. What is transcription? Ans: synthesis of RNA which carries the genetic information present in DNA. Q. What is the composition of RNA polymerase in prokaryotes? Ans: RNA polymerase consists of five polypeptide chains including two chains of ÃŽ ± (alpha) polypeptide and one chain each of ÃŽ ² (beta) and ÃŽ ²ÃƒÅ Ã‚ ¹ (beta dash) and ÏÆ' (sigma) polypeptides. Q. What is the function of sigma factor of RNA polymerase in prokaryotes? Ans: The function of sigma factor in prokaryotes is Promoter recognition and initiation of transcription. Q. What are the steps in transcription? Ans: The entire process of transcription can be divided in to following steps: (1) Template recognition, (2) Initiation, (3) Elongation and (4) Termination. Q. What is a Promoter? Ans: Promoter is defined as a sequence of DNA having the signal which directs the proper binding of RNA polymerase to DNA and activates it to a form which is capable of initiating the transcription. Q. What is the role of NusA protein? Ans: NusA protein, helps in elongation, and promotes pausing and termination at specific sites in prokaryotic transcription. Q. How termination of transcription occurs in prokaryotes? Ans: The termination of mRNA chain in prokaryotes is brought about by certain termination signals on DNA. These DNA sequences providing termination signals are called terminators (Gupta, 2007). Once the enzyme hits the terminator, it falls off the template and the transcription stops. The termination signals whenever found on DNA can be of two types: (i) Rho (Ï ) dependent termination and (ii) Rho (Ï ) independent termination. Q. How many RNA polymerases are involved in eukaryotic transcription? Ans: three classes of RNA polymerases (Pol I, Pol II and Pol III) have been identified which are involved in the transcription of different class of eukaryotic genes. Q. What the functions of Pol I, Pol II and Pol III? Ans: The functions of Pol I is Ribosomal RNA synthesis, Pol II is mRNA synthesis and Pol III is tRNA synthesis, 5S and other small RNA synthesis. Q. What are transcription factors? Ans: transcription factors are proteins which are needed for initiation of transcription, but are not a part of RNA polymerase. Q. What is Hogness box? Ans: The second region of eukaryotic promoter which is similar to -10 region of prokaryotes. is called the TATA box or Hogness box. Q. What is the role of transcription factor TFIIF and TFIIS? Ans: the transcription factor TFIIF accelerates RNA chain growth relatively uniformly, in concert with RNA polymerase II or pol II while transcription factor TFIIS helps elongation of RNA chain, by relieving the obstructions in the path of such elongation. Q. How TFIIS helps in elongation of RNA? Ans: TFIIS is known to function by first causing hydrolytic cleavage at 3Ê ¹ end of RNA chain, which are stuck and can not elongate. Q. what is the role of small nucleur RNA-protein complex? Ans: Termination takes place at termination sites which are present away from the site of 3Ê ¹ end of mRNA. The 3Ê ¹ end of mRNA will be generated due to post-transcriptional cleavage. This cleavage, at the end, is believed to be achieved by snurp (small nucleur RNA-protein complex). Q. How does Rho (Ï ) helps in termination of transcription? Ans: When RNA polymerase hits the terminator sequences, it pauses for a short time. During this period the rho factor reaches the RNA polymerase and causes it to fall off the template. MCQs: 1. Transfer of genetic information from DNA to mRNA? a. translation b. transcription c. transformation d. All of the above 2. During transcription the DNA strand which have a sequence homology with the RNA is known as: a. coding strand b. non-coding strand c. Both a and b d. None of the above 3. During transcription the strand which is complementary to RNA and serves as the template for RNA synthesis is known as? a. coding strand b. non-coding strand c. Both a and b d. None of the above 4. The principal enzyme involved in transcription is: a. RNA polymerase b. DNA polymerase c. transcription factor d. a and b only 5. RNA polymerase is: a. RNA dependent b. DNA dependent c. protein dependent d. hormone dependent 6. The RNA polymerase molecule thus can be represented as: a. ÃŽ ±ÃŽ ²2ÃŽ ²ÃƒÅ Ã‚ ¹ÃÆ' b. ÃŽ ±ÃŽ ²ÃŽ ²ÃƒÅ Ã‚ ¹ÃÆ'2 c. ÃŽ ±2ÃŽ ²ÃŽ ²ÃƒÅ Ã‚ ¹ÃÆ' d. ÃŽ ±ÃŽ ²ÃŽ ²ÃƒÅ Ã‚ ¹2ÏÆ' 7. The function of ÃŽ ± subunit is: a. Template binding b. Nucleotide binding c. Both a and b d. Enzyme assembly 8. Sequence of DNA having the signal which directs the proper binding of RNA polymerase to DNA is known as: a. Hogness box b. promoter c. CAAT box d. None of the above 9. The sigma factor is necessary for the formation of: a. promoter-enzyme complex b. Enzyme assembly c. CAAT box d. All of the above 10. The dissociation of sigma factor marks the entry of NusA protein: a. TF IIB b. TF IIE c.TF IIS d. Nus A protein 11. Termination of transcription in prokaryotes is: a. Rho (Ï ) dependent b. Rho (Ï ) independent c. both a and b d. a only 12. Hairpin structure for termination of transcription is found in: a. Rho (Ï ) dependent b. Rho (Ï ) independent c. both a and b d. a only 13. which RNA polymerase is found in Eukaryotes: a. Pol I b. Pol II c. Pol III d. All of the above 14. TATA box of eukaryotes is comparable to which sequence of prokaryotes: a. pribnow box b. CAAT box c. Hogness box d. All of the above 15. Transcription factors helps in: a. initiation b. elongation c. termination d. a and b only 16. At what region of DNA does RNA polymerase first bind to a gene: a. Initiation site b. Transcribed region c. Promoter d. Intron 17. RNA polymerase adds new nucleotides to the growing RNAs at what end? a. 3Ê ¹ end b. 5Ê ¹ end c. both a and b d. none of the above Key: 1-b, 2-a, 3-b, 4-a, 5-b, 6-c, 7-d, 8-b, 9-a, 10-d, 11-c, 12-b, 13-d, 14-a, 15-d, 16-c, 17-a. ASSIGNMENTS/TUTORIALS Q. 1: Difference between prokaryotic and eukaryotic transcription initiation. Q. 2: Explain the role of RNA polymerase in prokaryotes. Q. 3: Eukaryotes contain multiple RNA polymerases explain their role? Q. 4: Explain Rho dependent and Rho independent termination of transcription in prokaryotes. Q. 5: What are transcription factors? discuss the role.