Cells Biological Essay Example for Free

Cells Biological Essay I) Observation of starch grains 1. A potato was cut by using a cork barrier to obtain a piece of it. 2. The small piece of potato was placed on the centre of the glass slide and enough pressure was applied with fingers to squeeze it until small amount of juice was force out. The piece of potato was discarded leaving the juice behind on the glass microscope slide. 3. A drop of water was added to the potato juice and the glass slide was then covered with a clean cover slip. 4. The slide was examined: under low power (10X), then high power (40X). A drawing of 4-6 starch grains was made to illustrate the shape and other observable details for each, low power (10X) and high power (40X). 5. The experiment was preceded by staining the grains using the irrigation technique. (Irrigation technique: A drop of iodine was placed at one edge of the cover slip. A filter paper was brought into contact with the water at the opposite edge of the cover slip. As water was absorbed by the filter paper, iodine on the other side of the cover slip was drawn underneath it and the sample was stained.) 6. The iodine-stained mount was examined under low power (10X) and high power (40X). 4-6 starch grains were drawn to illustrate their shape and structure. These drawings were included in the microscope data sheet as results. II) Observation of onion cells 1. An onion was cut into half and one of its fleshy scale petals was removed. 2. The onion petal was snapped backwards and a forceps was used to tear away a piece of thin epidermal lining from inside the onion. A 1cm square piece of lining was placed onto the microscopic glass slide. 3. A drop of water was placed on the onion epidermal lining and the lining was covered with a cover slip. It was examined under a microscope at low power (10X) and then high power (40X). A drawing of the observations was made. The details that were observed in the preparation were included. . The parts of the onion cells were labelled accordingly. 4. The experiment was preceded by staining the onion lining with iodine by irrigation technique as described earlier. 5. It was examined again under low power (10X) and high power (40X). 4-6 onion cells were drawn in the microscope data sheet as observation. The parts of the onion cells were labelled completely. III) Observation of cheek cells 1. A clean glass microscope slide was obtained and a drop of water was placed in the centre of the slide. 2. A flat toothpick was hold against the inner cheek and the inner cheek was gently scraped with the flat edge of a toothpick. The cheek cells were spread in the drop of water on a microscope slide. 3. The specimen was covered with a cover slip and air bubbles were avoided. 4. It was observed under high power (40X) and a drawing of 4-6 cells was made. 5. The details that can be observed in the preparation were included and were labelled accordingly. 6. The experiment was preceded by staining the cheek cell slide with methylene blue by irrigation technique. 7. The cell with structures observed was drawn in the microscope data sheet as part of the results. Nucleus, nuclear membrane and cell membrane were labelled. Discussion: Under microscopic examination, organelles of the cell are enlarged to be observed. In onion cells (plant cell), cell wall, cell membrane, cytoplasm and nucleus are observed. In cheek cells (animal cells), cell membrane, cytoplasm and nucleus are observed. The difference between plant cells and animal cells are presence of organelles and their cell shape. From the observation of onion cells and cheek cells, it there is presence of cell wall in onion cell (plant cell) but it is absent in animal cell .The presence of cell wall contributes to the fixed, rigid shape of plant cell whereas animal cell is irregular in shape. Different types of stain colour for particular parts of a cell respectively so that the translucent parts of the cells can be viewed more clearly and can be studied easily. Iodine is often used as an indicator for starch. Hence, starch grains and onion cells are more clear and visible when iodine stains starch present in the cells. During observation of starch grains, starch is mixed with iodine solution where dark blue solution is observed, representing a starch/iodine complex. Staining a plant cell with iodine allows us to see the onion cell wall. Methylene blue binds well with negative charge molecules (DNA) which allows us to see the nucleus of the cell. It stains nuclei acid found in the nucleus, making nucleus more observable. For precaution, glass slide is make sure is clean and perfectly transparent by holding the slide by its edge. Glass slide is make sure not to be dry so that the cell can be observed under the microscope. During wet mount, air bubbles that will interfere the viewing the organisms’ movement is to be avoided by putting the covers lip gently on the slide. When observing the specimen, adjust the iris diaphragm or light level to achieve optimum contrast. Low power is always to be used first as to know the location of a good area for observation.

The History of Jamaican Slavery :: American America History

Jamaica’s history is full of social unrest. The island was originally inhabited by the Arawaks. The Arawaks were a peaceful, pleasant race. In his History of the British West Indies, Sir Alan Burns says, "all accounts credit them with being generous-minded, affectionate and good-humoured" (37). Once Jamaica was "discovered" by Spain in 1494, however, the Arawaks, who had inhabited the island for centuries, quickly died off due to the harsh treatment of the Spaniards. Spain never really developed the land, however, and thus when British forces invaded in 1655, Spain chose not to focus much energy on defending the island. The British found Jamaica to be much more profitable than the Spanish had. It eventually became one of the most lucrative colonies in the British empire due to its dominance in sugar exports: from the mid 1700’s until the close of the slave trade in Jamaica in the 1830’s, Jamaica accounted for 42 percent of sugar imported into Britain (Burnard and Morgan 3). Unfortunately, these benefits for the British empire came at a significant cost to the hundreds of thousands of Africans who became unwillingly caught up in the trade triangle between England, Africa and the Caribbean. In their essay "The Dynamics of the Slave Market and Slave Purchasing Patterns in Jamaica, 1655-1788," Trevor Burnard and Kenneth Morgan say: "Jamaica had the largest demand for slaves of any British colony in the Americas" (2). By the end of the eighteenth century there were more than 300, 000 slaves in Jamaica; and the fact that the slaves outnumbered the plantation owners was unsettling for many of the wealthy, white inhabitants of the island. The political system basically consisted of a governor who represented the Crown and the Assembly of Planters, who both were against the slaves. Adding to the unrest of the island was the existence of the Maroons. When the British invaded the island they demanded that the Spaniards surrender. In miscalculation, however, they gave them time to consider the offer. The Spaniards fled the island, but not before setting loose their cattle and freeing their slaves. These freed slaves then retreated to the mountains and developed their own threatening communities in the wild mountain interior of Jamaica (Hamshere 140). Often they terrorized the English by setting fire to homes and buildings or by murdering soldiers. The Maroons were not truly a vicious people, however they did feel the need to defend their freedom from the British by any means necessary.

The Masque of the Red Death

â€Å"The Masque of the Red Death† Literary Analysis: A Look at Imagery We continue our literary analysis of â€Å"The Masque of the Red Death† by Edgar Allan Poe with a look at the graphic imagery in the short story. players †¢ slide 1 of 4 Imagery is the use of figurative or descriptive language to create a vivid mental picture. It involves at least one of the five senses–sight, sound, touch, feel, taste. Imagery in â€Å"The Masque of the Red Death† is ghastly. †¢ slide 2 of 4 Example of Imagery – â€Å"There were sharp pains, and sudden dizziness, and then profuse bleeding at the pores, with dissolution.The scarlet stains upon the body and especially upon the face of the victim, were the pest ban which shut him out from the sympathy of his fellow men. † (145). Senses – Sight, Touch Analysis – Poe establishes the mood and setting of the story with the vivid description of the Red Death. The passage establishes the h orror of the disease and explains why the guests would react to the blood stained intruder at the end of the story. †¢ slide 3 of 4 Imagery in the 7th RoomExample of Imagery – â€Å"The seventh apartment was closely shrouded in black velvet tapestries that hung all over the ceiling and down the walls, falling in heavy folds upon the carpet of the same material and hue† (146). Senses – Sight, Touch Analysis: The oppressiveness of the 7th room contrasts the gaiety of the previous six. The darkness of the room and the heaviness and darkness of the curtain symbolizes death. No wonder none of the guests wish to come near it. Note the pun on â€Å"shroud. † Example of Imagery – â€Å"The panes here were scarlet–a deep color†¦.In the corridors that followed the suite, there stood, opposite to each window, a heavy tripod, bearing a brazier of fire, that projected its rays through the tinted glass and so glaringly illuminated the room. And thus were produced a multitude of gaudy and fantastic appearances†¦ The effect of the firelight that streamed upon the dark hangings through the blood tinted panes was ghastly in the extreme† (146-7) Senses – Sight Analysis – So much for peaceful death. The images created by the brazier of fire and blood tinted glass give the room of death a ghastly appearance.The gaudy and fantastic appearances, the blood tinted panes, and the fire create an image of hell, hinting that perhaps the guests and the Prince fear not just the Red Death, but their eternal fate. †¢ slide 4 of 4 More Examples Example of Imagery – â€Å"Its pendulum swung to and fro with a heavy monotonous clang; there came from the brazen lungs of the clock a sound which was clear and loud and deep and exceedingly musical† (147). Senses – Sound Analysis – No wonder the musicians stopped when this clock struck.Poe uses personification–brazen lungs–to em phasize the deepness of the â€Å"heavy monotonous clang,† a clang that serves as an hourly reminder to the guests that death is approaching. Example of Imagery – â€Å"The figure was tall and gaunt, and shrouded from head to foot in the habilments of the grave†¦ His vesture was dabed in blood and his broad brow, with all the features of the face was besprinkled with the scarlet horror. † (149). Senses – Sight Death – The personified Red Death strikes fear and anger in the hearts of Prospero and his guests.Once the Red Death appears, it never leaves. Symbolism in â€Å"The Masque of the Red Death† Why are there seven rooms in â€Å"The Masque of the Red Death†? Learn all that and more with this guide to symbolism. latest †¢ slide 1 of 6 Edgar Allan Poe's â€Å"The Masque of the Red Death† should be studied at many levels: (1) the literal level – the literal level is a study of the events that actually take plac e in the story; (2) an allegorical level – an allegory is a story in which the objects, characters, and events are symbolic of something grander in scale.In order to understand the story allegorically, one needs a firm understanding of symbols in â€Å"The Masque of the Red Death. † †¢ slide 2 of 6 Symbols ; Analysis The Red Death symbolizes the inevitability of death. Although there is no specific disease with the exact symptoms described in the story, critics believe the disease's description has elements of tuberculosis, a disease which killed many of those close to Poe. It also brings forth memories of the Black Death which depopulated much of Europe during the Middle Ages.The Castle represents man's efforts to prevent death. Regardless of wealth, social position, or popularity, death arrives as an uninvited guest. Prince Prospero symbolizes the end of feudalism. Prospero's inviting only wealthy knights and ladies to his castle at the expense of peasants and c ommoners represents the socioeconomic divide between landowners and peasants that existed during the feudalistic period. It is not coincidental that the Black Death, which reduced the number of workers, led to a demand for labor and played an important role in ending feudalism in Europe.The Ebony Clock is a constant reminder of death and symbolizes the inevitability of it. The revelers could neither stop its pendulum from swinging nor could they prevent its ominous tones from dampering their enthusiasm. †¢ The Seven Rooms represent the stages of life. More on this later. The Masqueraders symbolize all humans and gives creedence to the interpretation that the seven rooms represent the seven ages of man (covered further in the next section). †¢ slide 3 of 6 Color Symbolism Colors play an important role in this story:Red – The most obvious color symbolism in â€Å"The Masque of the Red Death† is in its title. Red symbolizes death and blood. The gruesome descript ion of the Red Death gives the color a ghastly connotation, especially in light of the red window panes contained in the death room at the far western end of the imperial suite. Black/Ebony – The seventh room was â€Å"closely shrouded in black velvet tapestries that hung all over the ceiling and down the walls, falling in heavy folds upon a carpet of the same material and hue† (146).This seventh room contains â€Å"no light of any kind† and represents the darkness of death. In this room stands the ebony clock. Upon hearing its chimes the guests were reminded of death: â€Å"the giddiest grew pale, and the more aged and sedate passed their hands over their brows as if in confused reverie or meditation† (147). Blue/Purple/Green/Orange/White/Violet – These are the colors of the first six rooms in the imperial suite. I will address them together insomuch that they represent a prism and therefore reflect a progression, lending creedence to the interpre tation that the story is an allegory for life.This interpretation, however, is complicated by the fact that the color of Prospero's room do not occur in the same sequence as they do in a prism, possibly reflective of Prospero's twisted sense of fairness or an attempt by the author to associate particular colors with a specific period in life. †¢ Others interpret the 7 rooms in â€Å"The Masque of the Red Death† as a symbol of Prospero's indulgence in the seven deadly sins: 1. Pride/Vanity – Pride is the excessive belief in one's own abilities, similar to vanity, which is setting one's heart on things of little value.Prospero's belief that he is more powerful than death is a vivid demonstration of pride. 2. Envy – It is unclear who the Prince might envy, but he sure is trying hard to impress someone. 3. Gluttony – Gluttony is the act of consuming more than one is required. Instead of using his means to protect more people, something he is obligated to do as prince, he lavishes his guests with â€Å"ample provisions† and â€Å"the appliances of pleasure. † 4. Lust – Lust is an excessive craving for the pleasures of the body, usually associated with sex. The era in which Poe wrote prohibited he explicit or implicit description of sex, but what do you think was going on at an anything goes party? 5. Anger – The Prince becomes angry with the uninvited guest and attacks it. 6. Greed – Although it is apparent Prince Prospero shares his wealth with a thousand guests, he helps those who need it least and withholds his substance from those in need. 7. Sloth – Sloth is the absence of work. The prince seems like a hard worker; his work, however, is on the physical realm not the spiritual realm. †¢ slide 6 of 6 What do you think they mean? If you have an alternate interpretation, let me know in the comments.

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