Parthenogenesis Essay -- Asexual Reproduction, Honeybees

Parthenogenesis is a natural form of asexual reproduction found most commonly in lower organisms and plants. Sometimes known as virgin birth, parthenogenesis, involves the growth of an individual without fertilization. Discovered in the 18th century by naturalist and philosopher, Charles Bonnet, parthenogenesis is a progressive evolutionary strategy that some organisms have employed to maintain a colony. Just as there are benefits to organisms that utilize parthenogenesis, like reproduction without the need of male gametes, there are costs, such as a decrease in genetic variation. In the intricate eusocial organization of honeybees, there are three social classes –queen bee, worker bees and drone bees. The queen bee, as the name entails, holds the superior position in the colony. The queen bee lays all the eggs in the colony, being the only bee with a set of completely developed ovaries and having life-long fertility (Back Yard Beekeepers Association n.d.). After only one mating flight were the queen mates with a couple male drone bees, she stores the sperm to later fertilizes some of the eggs. The eggs that get fertilized develop into female worker bees and the eggs that develop without fertilization produce male drone bees. Due to the high maintenance of both the colony and its products, i.e. honey, most of the bees in a hive are female worker bees. These worker bees carry on a magnitude of different tasks, not including reproduction, which is reserved only for the queen. The male drone bees are reserved for mating with the queen bee. Following copula tion, the drone dies because of their barbed sex organ (Back Yard Beekeepers Association n.d.). Scientists have been puzzled at how this multifaceted organization is maintained bu... ...nd genetic factors play a part in sex-determination (Slobodchikoff and Daly 1971). However in some other hymenopterans, parthenogenesis occurs via thelytoky parthenogenesis. There is a subspecies of honeybee, the Cape bee (Apis mellifera capensis), which is known to exhibit thelytoky, the production of diploid females from unfertilized eggs, eliminating the paternal genome (Heimpel and de Boer 2008). In the case of the Cape bee, the queen bee determines whether the eggs are haploid or diploid (Oldroyd et al. 2008). By thelytoky parthenogenesis, the Cape queen be can produce clones of herself (Oldroyd et al. 2008). Undergoing a different form of parthenogenesis gives Cape bees the advantage of creating males that could mate with other queens (Oldroyd et al. 2008), involving one individual for reproduction, and a decrease in gene loss (Slobodchikoff and Daly 1971).

Macbeth : a tragic hero or bloody tyrant? Essay

Written by William Shakespeare probably in late 1606 or early 1607, Macbeth is considered by many people to be the darkest of Shakespeare’s works. The play is a tragedy about death and deceit amongst the Scottish noblemen. It focuses on the rise and fall of the main character, Macbeth. The argument on whether Macbeth is a tragic hero or a bloody tyrant still remains unsettled. In order to answer this question, we have to define the characteristics that make up a tragic hero. According to Dr. Peter A. Smith from the English department of Kentucky State University, a tragic hero possesses many several criteria. Firstly, the character must be of noble stature, meaning he is a man with outstanding quality. His actions must affect an excessive amount of people. Secondly, his downfall is the result of his tragic flaw or â€Å"hamartia†. However, the most common flaw is excessive pride or â€Å"hubris†. Thirdly, the hero’s decline is thew result of his own â€Å"free will†. Although â€Å"fate† has a very important part in the play, there is always a factor of choice portrays in the story. Fourthly, the audiences are usually left feeling that the hero’s misfortune is not wholly deserved. The fifth criterion is that the tragic hero will eventually realise what went wrong but it is too late to undo the harm. Lastly, after the death of a tragic hero, the audiences feel the cleansing of emotion or â€Å"catharsis†. On the other hand, a bloody tyrant can be identified as some one who is self-deceived, remorseless, unmerciful, and avaricious. The character should be of bad reputation and is generally disapproved by others. They should be lacking of consideration and sympathy for others. Also, they should exhibit a constant yearning for more and more power. Macbeth, at the different stage in the play, possesses many characteristics of both a tragic hero and a bloody tyrant. In the beginning of the play, Macbeth is portrayed as a brave warrior who has fought for King Duncan and has just won the battle. On his way back from his assignation as Thane of Glamis, he encountered the three witches who greeted him with many pleasant predictions. Their prophecies were the fact that triggered Macbeth’s ambitious soul. However, he was still seen as genuinely loyal to the King â€Å"The service and the loyalty I owe, †¦Are to your throne and state†¦ Which do but what they should by doing everything Safe toward your love and honour.† (Act 1: Scene 4: L 22-27) He already appeared to fit the criterion of tragic hero since he was courageous and respected. He has saves Scotland and many lives from the battle. After Duncan had announced that his son, Malcolm, would succeed to the throne, we first learned of his flawed personality. â€Å"Stars, hide your fires, Let not light see my black and deep desires,† (Act 1: Scene 4: L.50-51) He was asking the stars not to shine because the light would make others see his dark desire. He did not want anyone to know about his future evil plan. So far, Macbeth’s character still corresponded to the characteristics of a tragic hero. We must see how his character developed. In the next scene, Macbeth met his wife, Lady Macbeth, who appeared to have thoroughly planned out Duncan’s murder. She encouraged her husband to eliminate Duncan so that Macbeth, in the near future, would be entitled the king of Scotland. However, Macbeth’s conscience was troubled. â€Å"†¦Besides, this Duncan†¦, hath been So clear in his great office, that this virtues Will plead like angels, trumpet-tongued against The deep damnation of his talking-off.† (Act 1: Scene 7: L.16-20) He knew that by killing Duncan who represented a figure of decent human being, heaven itself would detest his decision and he would be condemned. After struggling with his conscience and showing his reluctance to betray the king, he finally decided not to kill Duncan. â€Å"We will proceed no further in this business He hath honoured me of late, and I have bought Golden opinion from all sorts of people,† (Act 1: Scene 7: L.31-33) Macbeth was, perhaps, being selfish and wanted to be admired by the people for a bit longer, or his conscience might be causing his determination to weaken. Both reasons demonstrated that he was showing mercy, and mercy was definitely not a quality of a bloody tyrant. At this stage, he was not yet a bloody tyrant. However, later when Lady Macbeth insulted him by calling him a coward and questioning his masculinity, Macbeth changed his mind. Lady Macbeth’s speech was considered to be very persuasive. She also brought up the concept of being the same in action as in desire to Macbeth. It seems as of every time Macbeth gains back his conscience and follows the path of righteousness, his fatal weakness, which is ambition, always spurs him on and leads him back to the vicious path. His wife also plays quite a major role in manipulating Macbeth to do as she desired. He chooses evil over goodness. This is his own â€Å"free will.† The external force that keeps pressuring him cannot control or decide for him. After murdering Duncan, persuaded by his wife, Macbeth shows the sign of being quite repentant, hoping to undo the crime. â€Å"Wake Duncan with thy knocking: I would thou couldst† (Act 2: Scene 2: L.77) His wife apparently has forced him to do something a bit against his will. At the same time that this happened, Malcolm and Donaldbain decided to elude to England and Ireland respectively to escape the accusation. Macbeth, therefore, was entitled to be king and accessed to the throne. Once Macbeth realised the suspiction BanQuo had on him, including his fear for the witches’ prophecy, that Banquo would be father of a king, would become true, he decided to get rid of Banquo and his son, Fleance. Fortunately, Fleance has escaped. His ambition and pride started to increase. His plan to kill Banquo was kept secret from his wife. This showed that he had gained more self-confidence. His flaw has driven him to kill. Once Macbeth ascended the throne, he organised a feast at his castle. In my opinion, the feast represents the turning point of his character in the play. He began to show more of the vicious qualities. The ghost of Banquo has appeared to him at the banquet, and he began to hallucinate. After the guests have left, Lady Macbeth tried to calm him down. Macbeth was so mad that he has vowed to destroy anyone standing in his way. He was now in the point of no return. â€Å"†¦I am in blood Stepped in so far that should I wade no more †¦ Strange thing I have in head that will to hand, Which must be acted ere they may be scanned† (Act 3: Scene: 4: L.140) â€Å"We are yet but young in deed† (Act 3: Scene 4: L.144) Macbeth was saying that he has done so many bad deeds that he could barely wait to engage in the evil acts again. We could clearly see at this stage that Macbeth’s character has developed into someone who appeared to be malevolent by nature. He had lost all his good equalities. His speech showed his extreme hunger for power and control. He would kill according to his will. Macbeth later went to see the witches again and has received three apparitions. The witches told him that someone who was â€Å"none of woman born† would bring about his death. This prophecy has made him even more arrogant thinking that he was invincible, and it seemed to give him new pleasure for killing. He has Macduff’s family murdered and his castle demolished. After the death of Lady Macbeth, he took actions into his own hands. In the end, he suffered from internal revolt and eventually killed by Macduff, who later revealed that he was born by caesarean. Even though, towards the end, Macbeth has adopted most of the characteristics of evil tyrant, his death produced â€Å"catharsis† in audiences. Our emotions are cleansed knowing that the throne is now in charge by good people. Macbeth started off as being a â€Å"tragic hero†, but eventually, towards the end, his madness and hallucination has transformed him into a â€Å"bloody tyrant.† Bibliography 1. www.literatureclassics.com/essays/371 2. www.shakespearehelp.com/macbeth_guide/ 3. www.kysu.edu/artsscience/ENG411/tragic%20hero.htm

How Far Henry the Eighth Pursued New Policies During the...

How Far Henry the Eighth Pursued New Policies During the Period 1509-1514 Henry VIII became king in 1509. His policies were completely different to his fathers’, Henry VII. Henry VII was a wise and calculating man, who would think through his actions before he would take them, he would consider the long term and short term advantages and disadvantages of his actions. However Henry VIII was quite the opposite and he was emotional and took decisions straight away without analyzing them unlike his father. These differences caused Henry VIII to purse new policies and abolish the traditional ones which had been used by his father. When Henry VIII took the throne in 1509, at the age of 17, he made it†¦show more content†¦When Henry VII was on the throne he had been imposing heavy taxes on the people. The people despised taxes and especially hated the two main taxmen, Richard Empson and Edmund Dudley. So Henry VIII tried to gain the popularity and the support of the people by executing Richard Empson and Edmund Dudley. This definitely gave him the short-term popularity he was after, but without tax, this would affect his finances. Henry VIII’s decision to continue the Hundred Years War cost the government a lot. Around  £1.7 million was spent on preparing England and its allies for war. His aim was to seize the French Crown, and make England and himself greater, by means of war. His policy on finance was not like his fathers, he didn’t realise what problems he would face after stopping tax. His ally in the war was his Father-in-law, Ferdinand Aragon and it was decided that Spain and England would go to war against France in 1512. But Henry VIII’s ideas of conquering France did not succeed. Firstly because the Spanish did not turn up to fight, due to the Pyrenees mountains, on the border of Spain and France. The English troops get dysentery due to the water in France as it was contaminated. Even though Henry VIII failed to attack France, this didn’t prevent him from trying again. In 1513, Henry VIII decided to attack France again, this time with the help of Maximilian who was