To determine the water potential of a potato tuber cell using varying salt solution.
Aim To determine the water potential of a potato tuber cell using varying salt solution. Introduction Osmosis is the diffusion of water molecules from a region where it has higher water potential to a region where it has lower water potential through a partially permeable membrane1. As osmosis is a type of diffusion the same things that affect diffusion have an effect on osmosis some of theses things are: * The concentration gradient - the more the difference in molecules on one side of the membrane compared to the other, the greater the number of molecules passing through the membrane and therefore the faster the rate of diffusion2. * The surface area - the larger the area the quicker the rate of diffusion * The size of the diffusing particles - the smaller the particle the quicker the rate and polar molecules diffuse faster than non-polar ones3. * The temperature - the higher the temperature the more kinetic energy the particles have and so the faster they move. From the diagram4 we can see the process of osmosis in a simple expression. On the right side there is pure water, which has the maximum water potential of 0. Water potential is the pressure created by water. As you can see from the diagram the pure water is pushing its way through the semi permeable membrane at a high pressure. This is its water potential. Water potential is measured in kilopascals (kPa)
The Importance of Being Earnest - 'We live, as I hope you know, Mr Worthing, in an age of ideals' what are these ideals in the context of the play in Act One, and how does Wilde present them to the audience?
'We live, as I hope you know, Mr Worthing, in an age of ideals' what are these ideals in the context of the play in Act One, and how does Wilde present them to the audience? In 'The Importance of Being Earnest', ideals are a dominant theme, and to that end are critical in determining the actions of the characters. Wilde is typically subtle in his presentation of these ideals, and consequently many of them come to be used as a means for satirising the society depicted. It is important to establish from the outset that Wilde's presentation of ideals utilizes the different characters as bastions for the various ideals, and in doing that subjects them to scrutiny when ridiculing their respective characterizations. One of the most important ideals presented is fittingly one of the first to become apparent; that being the division of the classes and the social status that they entail. On line 1 of the play, Algernon asks Lane, after playing the piano in the adjoining room: 'Did you hear what I was playing. Lane?' Lane's response: 'I didn't think it polite to listen, sir' is indicative of various aspects of his position. Firstly, his butlership requires that he should abstain from partaking in any activity considered to be distracting to his duties, of which listening to the piano would be one. Secondly, his position in society, that of one of the lower classes, demands utter
Explain how twin and adoption studies attempt to distinguish genetic and environmental factors underlying the onset of schizophrenia within families. Review the studies and discuss two limitations of this.
Psychology Essay Explain how twin and adoption studies attempt to distinguish genetic and environmental factors underlying the onset of schizophrenia within families. Review the studies and discuss two limitations of this. Schizophrenia is the label applied to a group of disorders characterised by severe personality disorganisation, distortion of reality, and an inability to function in daily life. Symptoms are mainly disturbances of thought processes, but also extend to disturbances of emotion and behaviour. There are two symptom categories - acute schizophrenia characterised by positive symptoms, such as hallucinations and delusions; and chronic schizophrenia, characterised by negative symptoms such as apathy and withdrawal. However, DSM-IV has now moved away from these definitions and classified schizophrenia into three main sub-types: paranoid, disorganised and catatonic. Understanding Schizophrenia More research has, probably, been devoted to trying to understand the nature of schizophrenia than any other mental disorder. Somatogenic approaches have focused on the role of genetic mechanisms influencing the propensity to develop schizophrenia, while psychogenic approaches emphasise the effect of adverse childhood experiences, particularly abnormalities in family interaction in the aetiology of the disorder. Twin studies Twin studies offer a
Tennessee Williams wrote in a letter that It (Streetcar) is a tragedy with the classic aim of producing a catharsis of pity and terror and in order to do that, Blanche must finally have the understanding and compass
Tennessee Williams wrote in a letter that "It ('Streetcar') is a tragedy with the classic aim of producing a catharsis of pity and terror and in order to do that, Blanche must finally have the understanding and compassion of the audience. This without creating a black-dyed villain in Stanley. It is a thing (misunderstanding) not a person (Stanley) that destroys her in the end." In your opinion, to what extent has Williams succeeded in his aims. Although there are many different viewpoints on a conventional tragic heroine, Aristotle made his views clear that a hero must fall from fortune and power, due to a tragic flaw, allowing an audience to feel catharsis at the end of the play. It can be argued that Stanley causes Blanche's downfall, however, it is clear that Blanche had brought this upon herself by creating a conflict between them and ensures her own downfall by other means such as her promiscuity and flux into fantasies. Williams makes it clear that a misunderstanding destroys Blanche in the end. This misjudgement can be seen in her aggressive teasing of Stanley and her uncomfortable belonging in multi-cultural New Orleans. From the beginning of the play, Williams makes it clear that 'the Kowalski and the DuBois have different notions' with Blanche withholding the Southern Belle attitude of 'Belle Reve'. However, it is clear that Blanche cannot cope with the stark
Duty and desire in Jane Eyre
How is the conflict between duty and desire explored in these texts? Desire is a term conveying a longing for a certain object, person or outcome. It is an emotion from the heart and is unaffected by social opinion. Duty, in contrast, is a moral obligation to an act, which is perceived to be selfless. The decisions made regarding these emotions are significant throughout 'Jane Eyre' and 'Wide Sargasso Sea'. However, these definitions were more extreme during the time that Brontë and Rhy's texts were written. In the 19th century, it was considered a completely selfish act for women to show desire, it was a vulgar emotion that women were expected to control and conceal. The female role during the 1800's was limited; they were expected to be passive and were passed from father to husband, similar to a possession. To perform one's duty to society was regarded as an unspoken rule imposed on all women, therefore, women never truly had the chance to express their true identity or gain real independence. The 19th century conflict between duty and desire was a key topic written about by many authors, predominately women, who illustrated personal experiences and beliefs through the characters and their decisions. In both Bronte's and Rhy's novels the authors illustrate the limitations imposed on women, society's views and expectations concerning the conflict, and the importance of
Compare how the past reveals feelings about a place in Nothings Changed with the ways another poet reveals feelings about a place or places in one other poem.
Essay Question: Compare how the past reveals feelings about a place in "Nothing's Changed" with the ways another poet reveals feelings about a place or places in one other poem. Nobody can help have feelings- they are a part of everyone. We feel differently towards an issue as different things happen to us. Feelings do not change with time. What we feel as a child stays with us even when we are older. Feelings can be positive or negative. The poets Tatamkhula Afrika and Grace Nichols are both trying to deliver a similar message about feelings. In the poem Nothing's changed, the poet is feeling anger towards the white people even though the Apartheid had been finished. "District Six. No board say it.... And the hot, white, inward turning anger of my eyes." This shows that the poet is feeling ferocity towards the People in District Six. This can be said because "District Six" has been written as a short, expletive sentence, which is full of anger. "No board says it: but my feet know" This shows that even though Apartheid has ended and all the boards which differentiate the black community from the white community have been removed, the poet still feels secluded from the community. "And my hands, and the skin about my bones, and the soft labouring of my lungs, and the hot, white, inward turning anger of my eyes." This shows that as he is walking along, his anger is
Outline the development of attachments
Developmental Psychology - Key Assessment Task a) Outline the development of attachments An attachment is a powerful bond between an infant and its caregiver. Infants form attachments because they are helpless at birth and so need caregivers to provide for and protect them. There are many long term effects of attachments, for example an attachment gives a foundation for emotional relationships e.g. the infant is learning how to form an emotional or "love" relationship. Schaffer and Emerson believed that infants form attachments by three stages, this argument was based on a large scale study of 60 infants in a working class area of Glasgow over 2 years. The first stage of attachment Schaffer and Emerson believed a child to go through happens when they are 0-6 weeks old, this is known as the Asocial Stage and involves the infant smiling and crying but not directing these emotions at individuals. The second stage of attachment is known as Indiscriminate Attachment and happens when the infant is 6 weeks to 7 months old; this involves the child seeking attention from different individuals. The last stage of attachment is Specific Attachments and happens when the infant is 7-11 months old, this stage shows a strong attachment to one individual, with good attachment to others following afterwards. b) Describe the procedures and findings of one study of individual difference in
Outline and evaluate two social psychological theories of aggression
Outline and evaluate two social psychological theories of aggression. (24 marks) Bandura believed that the potential for aggression may be biological, but the expression of aggression is learned. The social-learning theory (SLT) states that learning occurs through observation of a model. Imitation of an observed behaviour is more likely if the model is someone we aspire to or identify with or if they are rewarded. This is vicarious reinforcement. A child forms a mental representation of an event, including the possible rewards or punishments of the behaviour. When a child imitates an aggressive behaviour, they gain direct experience, and the outcome of the behaviour influences the value of aggression for the child. If they are rewarded they are more likely to repeat the behaviour. Children develop self-efficacy, which is confidence in their ability to successful carry out a behaviour. If aggressive behaviour is unsuccessful for a child, they will have a lower sense of self-efficacy so are less likely to behave this way in future. There is strong empirical evidence to support the SLT. For example, Bandura's Bobo doll studies found that children who observed a model behaving aggressively to the Bobo doll behaved more aggressively than those who observed a non-aggressive model and also imitated specific aggressive acts. This supports the theories claims that behaviour can be
Investigate the water potential of celeriac.
Aim Investigate the water potential of celeriac. Apparatus Celeriac - this is the specimen that we will be finding the water potential of. .00 mol dm-3 sucrose solution - this will be placed in the test tube in which the experiment will take place. We will dilute the solution to produce a range of concentrations. 0.0ml Graduated Pipettes (x2) - I had a choice of 5.0ml, 10.0ml and 20.0ml graduated pipettes. I chose this size pipette because it is time efficient and accurate at the same time. It is an accurate piece of equipment because as opposed to standard pipettes, this graduated pipette has 0.1ml graduations to ensure the utmost accuracy. One pipette will be used for water and one will be used for sucrose solution. 250ml Beakers (x2) - these will be used to hold water and the 1.00 mol dm-3 sucrose solution in a safe environment. Cork Borer - this will be used to cut the precise shape of the celeriac. This will also ensure that the surface area to volume ratio is constant throughout the experiment. Razor - this will be used to cut the pieces of celeriac to a precise length. Ruler - this will be used to measure the length of celeriac that will be used in the experiment. Scales - they will be used to measure the mass of celeriac before and after the experiment with accuracy. Therefore, the mass increase/decrease can be calculated after the experiment. These scales
Preparation of propanone from propan-2-ol
Date: 11/10/2011 Exp. No.: 23 Title: Preparation of propanone from propan-2-ol Aim: The aim of this experiment is to prepare propanone by oxidizing propan-2-ol with acidified potassium dichromate solution. Introduction: Ketones and aldehydes are important series in preparation of other compounds and they are commonly prepared by oxidizing alcohol which is done in this experiment. The experiment is an oxidation reaction where a secondary alcohol (propan-2-ol) is oxidized by acidified potassium dichromate. The reaction does not need to be heated but should be placed in an iced water bath as the reaction is highly exothermic. The product is propanone and no catalyst is needed for the reaction. The propanone is serparated from the reaction mixture by simple distillation and is purified using anhydrous cacium chloride. The equation of this reaction is as follow: Chromic acid is produced in situ by adding potassium dichromate (VI) with sulphuric acid and water. K2Cr2O7 + H2O + 2H2SO4 ? 2 H2CrO4 + 2 NaHSO4 The term chromic acid is usually used for a mixture made by adding concentrated sulfuric acid to a dichromate, which may contain a variety of compounds, including solid chromium trioxide. Chromic acid features chromium in an oxidation state of +6. It is a strong and corrosive oxidising agent. Apparatus and chemicals: Apparatus: Quick-fit distillation setup,
