An Investigation into the Effects that Different Light Intensities have on the Speed of Woodlice:
An Investigation into the Effects that Different Light Intensities have on the Speed of Woodlice: Introduction: Woodlice are one of the easiest terrestrial arthropods to obtain in large numbers throughout the year. Porcellio scaber, the most common species is not difficult to identify with the naked eye, and is large enough to be handled without employing special techniques. Their behaviour is relatively simple yet providing perfect examples of kinesis and taxis. i A species, which shows taxis, can orient the direction of their movement with respect to the source of an external stimulus whilst kinesis is a steady-state dependence of the movement velocity on the stimulus intensity.iii Thus it is clear that kinesis will be the important response in my investigation as I am not concerned with the stimulus direction. Woodlice lack a waxy cuticle on their exoskeleton and have a high surface area to volume ratio. This means that they are prone to desiccation. As a result, much of their behaviour is concerned with reducing water loss. Woodlice will therefore tend to congregate in more humid, cooler and darker regions where their water loss will be lower.ii Although light does not affect the physiological state of woodlice in the same way as humidity and temperature, it plays a very important part in woodlice behaviour. Woodlice have a negative photokinesis- they move faster as
Examine the different kinds of prejudice and injustice which you have found in 'To Kill a Mockingbird'. How does Harper Lee convey these to the reader?
Examine the different kinds of prejudice and injustice which you have found in 'To Kill a Mockingbird'. How does Harper Lee convey these to the reader? 'To Kill a Mockingbird' was written by Harper Lee in 1960. Nelle Harper Lee was born on April 28, 1926 in Monroeville, Alabama, a city of about 7,000 people. She studied law at the University of Alabama and one year at Oxford University. After giving up working as a clerk for an airline she moved into a cold-water apartment in New York to concentrate on writing. She first handed this book to a publisher in 1957 but it was rejected so she took two further years to rework it before it was published as 'To Kill a Mockingbird' in 1960. The book tells a story very similar to Lee's own childhood. The town in which it is set is a small southern town just like her own with the characters matching friends and associates from her youth. It is set in the thirties and is a highly significant statement and important to that era. It was written at the time of the civil rights movement, which guaranteed basic civil rights for all Americans, regardless of race. 'To Kill a Mockingbird' was set thirty years before Lee wrote it, meaning she could use hindsight to give the story authenticity. Lee helped move the civil rights movement forward by reminding the population of the prejudice they had and showing them that something had to be done.
Fighter Pilot A Statistical Analysis of Reaction time and its Correlation with Dominant & Non-Dominant Hands
Fighter Pilot A Statistical Analysis of Reaction time and its Correlation with Dominant & Non-Dominant Hands Introduction This experiment seeks to determine reaction times in two groups of matched subjects; dominant and non-dominant hands, using the ruler drop test. Reaction time experiments are performed to measure the alertness of the mind and will give an indication of the speed of the reflexes that different groups of varied individuals have. The experiment tests how long it takes the brain to translate visual information into the voluntary motor commands, actions which lead to a ruler being grabbed. The shorter the length at which the ruler is grabbed, the shorter time and therefore the faster the person's reaction. The controls of these processes within the human body are the responsibility of the nervous system which is the seat of voluntary and involuntary movements along with language, emotion and memory. (1) The experiment begins with an environmental stimulus via light reflected from a moving ruler being dropped from a height above the subject's hand. (1) This transmits into a sensory nervous impulse within the optic nerve. Beginning in the retina of the eye, information is detected by photoreceptors (rods and cones) they relay the visual signals on to bipolar cells which transmit on to ganglion cells. (2) The axons of all ganglion cells in the retina of each
An experiment to investigate how the effect of varying concentrations of salt solutions play on the movement of water in a potato.
PRELIMINARY EXPERIMENT AN EXPERIMENT TO INVESTIGATE HOW THE EFFECT OF VARYING CONCENTRATIONS OF SALT SOLUTIONS PLAY ON THE MOVEMENT OF WATER IN A POTATO. AIM The aim of this experiment is to try and find out how different concentrations of salt solutions affect the osmotic activity in a potato tissue. Thus we will be able to find out if the mass of the potato has increased or decreased in the different concentrations of salt solution. APPARATUS > A Single Fresh Potato > McCarthy Bottles = x 5 > Corks = x 5 > Water = 20cm3 x 5 > 2 Molar Salt Solution = 150cm3 > Test Tube Rack to hold 5 test tubes > Pipette > Scalpel - To cut the potato tubes into cylinders > Weight Measuring Scales > Ruler - To measure the potato cylinders accurately to 2cm long. > Cork Borer > Cutting Board - Where the potato can be placed and cut safely > Marker Pen will be used to write on the test tubes so that I will be able to distinguish between the potato cylinders and determine which salt solution is in which test tube. DETAILED INFO ON HOW TO PREPARE THE SOLUTIONS REQUIRED Just like my final experiment, in this preliminary experiment I increased the concentration in my five bottles by 0.5 moles, until it reaches 2 molar. mole in 1 litre requires 58.5g of salt to be dissolved in it. Therefore as 1 litre is 1000 cm3, I was thus able to take these into account and do my
The Effect Of Temperature on the Respiration Of Yeast.
The Effect Of Temperature on the Respiration Of Yeast Introduction: - I am going to find out how temperature effects the respitory action of yeast. I am going to do this by using six different temperatures, 25oC, 30oC, 35oC, 40oC, 45oC and 50oC and a solution called TTC which is absorbed by the yeast cells turning them pink when hydrogen is removed from the metabolic pathway by the dehydrogenase enzyme. Background Information: - Yeast: - Yeast is unicellular fungus that buds profusely under favourable conditions. They are classified as sac-fungi (Ascomyctes) even though they are unicellular. Yeast is common in areas where there is sugar because of this they are given the name saccharomyces (Sugar fungi). They grow on the surface of fruits, in the nectar of flowers, in sap excluded from trees, in the soil and in fresh water. Yeasts are used in all sorts of arrears such as alcoholic fermentation (fermentation is the name given only to the anaerobic respiration of yeast) to baking bread. Yeasts are of a great economic importance and are yeast for biochemical research for example in respiration and enzymes. Yeast exists as Diploid or Haploid cells and divides by mitosis and meiosis. Yeasts are not plant or animal because they do not photosynthesise and they do not have any chloroplast. Yeast is a saprophyte. This is an organism, which obtains its nutrients from dead or
'An investigation into the ability of two strains of the yeast Saccharomyces cerevisiae to utilise different carbon sources as substrates for cellular respiration'.
'An investigation into the ability of two strains of the yeast Saccharomyces cerevisiae to utilise different carbon sources as substrates for cellular respiration' Introduction The purpose of this investigation is to compare the ability of two different strains of yeast to respire, when using different sugars as respiration substrates. Considering the lengths that have been reached to develop varieties of yeast with greater suitability and effectiveness for very particular fermentation purposes, it seems reasonable to suppose that two different strains of the same species of yeast, selected for their different fermentation properties, have developed requirements that are not uniform. As a result of the selection and development process, yeast best suited to ferment in a given application, possess a range of different characteristics. One such characteristic may be the ability to metabolise different carbon sources at different rates. This quality is important because in each application where different respiration substrates are available, a specific strain of yeast may be required. Yeast unable to utilise the available carbon sources will have undesirable fermentation rates, and therefore may not be selected for use in that application. The two yeast here compared, have two such different applications. The first yeast from the Saccharomyces cerevisiae variety is of the
Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL KNOWLEDGE
TABLE OF CONTENTS Biological Knowledge ... 3 Explanation ... 3 Types of solutions and its effects on plant cell ... 4 Factors affecting rates of osmosis ... 6 Outline Method ... 9 Apparatus ... 9 Materials ... 9 Risk Assessments ... 9 Precautions ... 9 Apparatus Diagrams ... 10 Factors to be controlled ... 11 Method ... 11 Calculations to be used ... 12 Predicted Results ... 12 Prior Test ... 13 Obtaining Evidence ... 16 Apparatus ... 16 Materials ... 16 Risk Assessments ... 16 Precautions ... 16 Method ... 17 Results obtained for Mass ... 18 Results obtained for Length ... 19 Analysis ... 21 Trends in the Bar charts ... 25 Scientific Explanation ... 25 Determination of molarity ... 28 How far I have reached my predicted results ... 30 Evaluation ... 32 Errors ... 32 Accuracy and reliability of my results ... 32 Extension work ... 33 Bibliography ... 33 INTRODUCTION Biology Coursework Aim: To find the molarity of potato tuber's cell sap. BIOLOGICAL KNOWLEDGE Osmosis is the diffusion of fluid through a semi-permeable membrane from a solution with a low solute concentration to a solution with a higher solute
To what extent were Malcolm X and the subsequent Black Power Movement the 'Evil Twin' of the Civil Rights Movement in the late twentieth century in the United States of America?
To what extent were Malcolm X and the subsequent Black Power Movement the 'Evil Twin'1 of the Civil Rights Movement in the late twentieth century in the United States of America? Malcolm X2 and the subsequent Black Power3 Movement (BPM) stemmed from the nationalist African American population and so took a different stance in their fight for Civil Rights than other leaders such as Martin Luther King4 (King). With this distinction, has come a historical debate into whether Malcolm X and the BPM aided or hindered the Civil Rights Movement (CRM); something that has been debated between historians such as Sitkoff and Cook. The purpose of this study is to decide whether Malcolm X and the BPM are indeed the 'evil twin' of the CRM or whether this title is unjust. Malcolm X was a black nationalist5 and a member of the Nation of Islam6. Malcolm X, through his father, garnered the beliefs of Marcus Garvey7 and his 'Back to Africa' campaign. He also believed in militancy as a method to attain black independence through the notion; 'fight violence with violence'. He believed that rather than allowing the continual persecution of African Americans by whites, it was rational for African Americans to defend themselves with as much force as was necessary as advocated in his 'by any means necessary'8 speech. This caused much tension between the two distinct civil rights movements because it
How is Orwell's attitude towards totalitarianism personified through the characters of Winston and O'Brian in this extract?
How is Orwell's attitude towards to totalitarianism personified through the characters of Winston and O'Brian in this extract? George Orwell's Nineteen Eighty-Four presents a negative utopian picture, a society ruled by rigid totalitarianism. The government that Orwell creates in his novel is ruled by an entity known as 'Big Brother' and in contrast to this, Winston Smith represents a rebellion, one which doesn't accept this ideology fed to him. Thus leading to his entrapment and confrontations with the complex character, O'Brian. Although the action deals in the future, there are a couple of elements and symbols, taken from the present and past. So for example Emanuel Goldstein, the main enemy of Oceania, is, as one can see in the name, a Jew. Orwell draws a link to other totalitarian systems of our century, like the Nazis and the Communists, who had anti-Semitic ideas, and who used Jews as so-called scapegoats, who were responsible for all bad and evil things in the country. Emanuel Goldstein somehow also stands for Trotsky, a leader of the Revolution, who was later, declared as an enemy "Within twenty years at the most, he reflected, the huge and simple question, 'Was life better before the Revolution than it is now?' would have ceased once and for all to be answerable". Another symbol that can be found in Nineteen Eighty-Four is the fact that Orwell divides the
Investigating the forces acting on a trolley on a ramp
Physics coursework Investigating the forces acting on a trolley on a ramp Contents Page 3 -> Method Page 4 -> Theory Page 7 -> Results Page 9 -> Error Page 18 -> Appendixes Method The aim of the investigation was to investigate the forces acting on a trolley as it rolled down a ramp, and also to investigate the factors which may contribute to the results. To do this, a trolley and a ramp set at a variety of angles of incline were used, and then, using a light gate, the speed at which the trolley was moving when it passed through the light gate was calculated. The variables were the starting distance of the trolley in relation to the light gate and the angle of the ramp. Firstly, the equipment was set up as in fig. 1. The trolley was then run down the ramp with a piece of card attached to the side. This card was of a known length and could hence be used to calculate the velocity at which the trolley was moving. While the light gate did actually calculate the velocity, it only gave the answer to 2 decimal places, whereas it gave the time to 2 decimal places. Furthermore, the light gate calculated the velocity with the assumption that the card was exactly 100mm, whereas when the card was actually measured, this was a value closer to 102mm (±0.5mm). Next, after the trolley had passed through the light gate, the information from that 'run' appeared
