Investigating Electricity.

GNVQ Science Unit 1 and 3 Investigating Electricity Section A: Voltage, Current and Resistance and Ohm's Rule Firstly, to being this assignment I will be introducing what exactly Ohm's rule is and what voltage, current, and resistance is and how they are measured. * Resistance: - resistance is a measure of the degree to which an electrical component opposes the passage of current. It is the ratio of the potential difference (i.e. voltage) across an electric component (such as a resistor) to the current passing through that component: R is the resistance of the component. If the resistance of a material is low then charges can pass through it easily. (Resistance = Voltage ÷ Current) * Current: - Electric current is the rate of charge flow past a given point in an electric circuit, measured in coulombs/seconds which is named amperes. In most DC electric circuits, it can be assumed that the resistance to current flow is a constant so that the current in the circuit is related to voltage and resistance by Ohm's law. (Current = Number of Coulombs per second) & (Unit of current = Amps) * Voltage: - Voltage is a measure of the energy required to move a charge from one point to another. A difference in the amount of electric charge between two points creates a difference in potential energy, measured in "volts," which causes electrons to flow from an area with more

  • Word count: 2351
  • Level: AS and A Level
  • Subject: Science
Access this essay

What different methods exist for studying genetic variation at a molecular level? How could an allele polymorphism mutation be shown to contribute to a disease/ trait?

What different methods exist for studying genetic variation at a molecular level? How could an allele polymorphism mutation be shown to contribute to a disease/ trait? Almost all human genetic variation is relatively insignificant biologically- that is, it has no apparent adaptive significance. Some variation such as a neutral mutations, alter the amino acid sequence of the resulting protein but produces no detectable change in its function. Other variation, for example, silent mutations, do not even change the amino acid sequence of a polypeptide. Furthermore, only a small percentage of the DNA sequences in the human genome are coding sequences (sequences that are ultimately translated into protein) or regulatory sequences (sequences that can influence the level, timing, and tissue specificity of gene expression). However, these supposedly silent variations may be useful in mapping specific genes in the human genome, is not allowing the study of variation amongst individuals in a population flourish. The co-existence of more than one variant of an allele is called genetic polymorphism. More precisely, an allele is usually defined as polymorphic if it is present at a frequency of >1% in a population. Variation among individuals however, need not only occur in base sequences in deoxyribonucleic acid (DNA), which codes for the production of a polypeptide molecule

  • Word count: 3230
  • Level: AS and A Level
  • Subject: Science
Access this essay

Objective:-To prepare a buffer solution and observe the properties of a buffer

Experiment E5 Preparation and Properties of a buffer Date: 23.3.2011 Name: Leung She Ting Cherry Class: 6A 20 Objective To prepare a buffer solution and observe the properties of a buffer Introduction Buffer is a solution that can resist dramatic pH change when a small amount of acid or alkali is added to it. It is made up of equal amount of a weak acid/alkali and its conjugate base/acid. The working principle of buffer can be demonstrated as below: Ethanoic acid is a weak acid that undergoes slight dissociation, CH3COOH (aq)+H2O(l) CH3CHCOO-(aq) + H3O+(aq) where the equilibrium position mainly lies on the left side. At the same time, sodium ethanoate undergoes complete dissociation, CH3COONa (aq) CH3COO- (aq) + Na+ (aq) in which its equilibrium position lies mainly on the right side. When a small amount of acid is added to the solution, the addition of H3O+(aq) will shift the equilibrium of CH3COOH (aq)+H2O(l) CH3CHCOO-(aq) + H3O+(aq) to the left. The increase of [CH3COOH] does not cause a significant change in pH, thus the pH of the solution is kept almost constant. On the other hand, if a small amount of base is added to the solution, CH3COOH(aq) will react with the base, giving out salt i.e. CH3COONa. This shifts the equilibrium of CH3COONa (aq) CH3COO- (aq) + Na+ (aq) to

  • Word count: 1288
  • Level: AS and A Level
  • Subject: Science
Access this essay

In this experiment, we investigated the relationship between the difference in work and mechanical advantage. Furthermore, we wanted to determine the difference between total work done lifting a 1kg mass up a height

The Relationship between Changes of Mechanical Advantage and Work Done Abstract (Moe Okubo) In this experiment, we investigated the relationship between the difference in work and mechanical advantage. Furthermore, we wanted to determine the difference between total work done lifting a 1kg mass up a height and dragging up a ramp as a function of mechanical advantage. We planned to change the height each times with pile-upped books and change the angles. Firstly, we measure the height of the books we piled up, the length. Then measure the angle of the ramp and we use a plank, and a spring balance to lift up and drag up the mass we repeat these steps for five times. In the result, when we changed height the work of lifting up the mass would not change but the work of dragging up the ramp would affect and we could see that when the angle of the ramp changed, work of dragging up would use more work. Also we could see that the mechanical advantage would affect too, it has getting less act when the angle of the ramp going bigger. Abstract (Eric Liu) Basically, in this lab we're going to determine the difference between total work done lifting a 1kg mass directly up a height h and dragging a 1kg mass up a ramp of length l as a function of mechanical advantage. How much easier and faster a machine makes your work is the mechanical advantage of that machine. In our experiment,

  • Word count: 1532
  • Level: AS and A Level
  • Subject: Science
Access this 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.

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

  • Ranking:
  • Word count: 1708
  • Level: AS and A Level
  • Subject: Science
Access this essay

"Only god has the right to interfere with our genes"

03.11.04 Greg Judge 1O4 RE COURSEWORK - PART B 845 WORDS "Only god has the right to interfere with our genes" Genetic engineering is when scientists manipulate the human genome to alter 'bad' genes; these genes are responsible for all types of diseases and conditions from cancer to the acclaimed 'fat' gene which is responsible for the obesity crisis that the modern world is currently facing. This practice has been controversial one because religions and other organizations across the world believe that genetic engineering is playing god as it allows man to create people with any mental and physical characteristics possible. As well as this, scientists would also be able to create food, livestock and even grow human transplant parts on animals that are grown to precise specifications. These could include food that lasts longer and animals that have more meat, all this is possible using genetic engineering and that makes genetic engineering a very controversial topic both in the political and religious communities. In my essay I am going to consider whether man should have the power of god to do this, I will look at the opinions and beliefs of 2 religions and my own personal opinion. The 2 religions will be looking at are Christianity and Islam. Christians agree that only god should have the right to manipulate our genes and characteristics because 'it is wrong to try

  • Word count: 891
  • Level: AS and A Level
  • Subject: Science
Access this essay

How has the Invention of Contact Lenses affected people's Sight?

Manon Mollard MP5a 14.12.04 Biology: The Impact of Man's Inventiveness on the Human Body. How has the Invention of Contact Lenses affected people's Sight? Introduction People with sight troubles have had the possibility of wearing glasses for a really long time, but the new technology made available contact lenses. In this essay, I am going to look at the different contact lenses types that exist, at who invented them and when, for which vision problems they are solution, at how to take care of them, at how common they are in our society and finally, I will write about my own opinion. What contact lenses are According to the Macmillan Dictionary (2002), contact lens may be defined as "a plastic lens that you wear in your eye to help you see more clearly". A very wide variety of contact lenses are available in today's society, including hard and soft (even if soft is by far more common now), disposable and extended wear; this makes it easy for each person to chose the appropriate type of contact lens for her. The main types of contact lenses are listed below: * Soft lenses: As these lenses are soft, they are made of a large percentage of water, and this allows oxygen to pass through the lens and reach the cornea. They are also more comfortable and easier to adapt to. * Rigid-gas

  • Word count: 2286
  • Level: AS and A Level
  • Subject: Science
Access this essay

Find out what kind of effect the strength of an electromagnet has if the number of turns on the coil and the current going through the coil are increased.

Physics Investigation Electromagnets Aim My aim for this experiment is to find out what kind of effect the strength of an electromagnet has if the number of turns on the coil and the current going through the coil are increased. Background Electromagnetic induction is the idea that magnetism can travel from one object to another even though they are insulated. A greater number of coils in the solenoid around the core will increase the strength of the field produced by that electromagnet. This is because the amount of power given to the solenoid and core is increased so the core receives an increase in power, so the domains become aligned strongly, and more domains become aligned. In addition, with an increase in coils the coils cover a greater surface area of the core. This means the coil covers more domains and therefore more domains are influenced. Each turn has it's own field so more turns mean more fields. The greater amount of turns causes constructive interference, which increases the size and strength of the magnetic field. The type of wire also affects the strength of the electromagnet. If a wire is thicker then current can flow more easily and the current will increase so the strength of the electromagnet will increase. In addition, the length of wire may also affect the

  • Word count: 1131
  • Level: AS and A Level
  • Subject: Science
Access this essay

Objective: To investigate the effect of using different carbon source on the growth of yeast cells.

NAME: FARAH NADZIRAH ROSLI CLASS: ALM 7 M 13 Title: Using Different Carbon and Source for Growth Objective: To investigate the effect of using different carbon source on the growth of yeast cells. Background summary: Growth depends upon both the type of the nutrients available and their concentration. Cells are largely made up of the four elements: carbon, hydrogen, oxygen and nitrogen with smaller, but significant, quantities of phosphorus and sulphur. Accounting as they do for 90% of the cell's dry mass, all six elements are essential for growth. Hence, like all living organisms, microorganisms require an energy source, a carbon source and a range of nutrients for metabolic and cell growth. Microorganisms are small, easily dispersed and quick to multiply given a suitable environment. They grow on a wide diversity of substrates making them ideal subjects for commercial application. The microorganisms need organic carbon source, such as carbohydrates, as most of them are heterotrophic. Carbohydrates act as a respiratory substrate of cells. Microorganisms also need a nitrogen source for synthesis of DNA, RNA, ATP, coenzymes and chlorophylls. Apart from that, each species has its own optimum conditions within which it grows best. Respiration involves a series of metabolic pathway, which is a series of enzyme-controlled chemical reaction, where the product of

  • Word count: 1936
  • Level: AS and A Level
  • Subject: Science
Access this essay

Of all of the early scientists of the scientific revolution I am most impressed by Sir Isaac Newton.

Of all of the early scientists of the scientific revolution I am most impressed by Sir Isaac Newton. Newton is important because he contributed more to the development of science than any other person in history. Isaac Newton is remembered as the greatest scientific genius who ever lived. His discoveries about physics, light, and mathematics changed the world. I am even more impressed by what he overcame to reach his goals. He came to surpass even his own expectations. I am more impressed with the man than with the discoveries. So many people in history are viewed as larger than life, which can be dehumanizing. Newton was very much a human with very human emotions. Isaac Newton came from a family of farmers. His father dies three months before he was born. Isaac's father was a wealthy landowner but was uneducated and could not even sign his own name. Isaac did not lead a privileged life; he was basically treated like an orphan. Isaac had a very unhappy childhood. Isaac is only ten when his grandfather, James, dies and James left him nothing in his will. There is also no doubt that Isaac felt very bitter towards his mother and stepfather. When he was reflecting on his sins at age 19 he wrote: "Threatening my father and mother to burn them and the house over them." Upon the death of his stepfather, Isaac lived with his extended family including his mother, grandmother,

  • Word count: 1026
  • Level: AS and A Level
  • Subject: Science
Access this essay