Experiment. Hypotheses: The higher the concentration of caffeine the higher the heart rate of the daphnia.
The effect of caffeine concentration on daphnia's heart rate Hypotheses: The higher the concentration of caffeine the higher the heart rate of the daphnia. Biological information: caffeine speeds heart rate, and circulation. Caffeine is a stimulant drug, which causes increased amounts of stimulatory neurotransmitters to be released. It belongs to a Group of chemicals called methylxanthines. Caffeine and similar compounds also inhibit a class of enzymes known as cyclic nucleotide Phosphodiesterases. These enzymes are, in part responsible for degrading a stimulatory signal produced when excitatory neurotransmitters activate different neurons in the central nervous system (CNS). When they are inhibited by caffeine, the stimulatory signal remains active for a longer period of time resulting in a greater sense of alertness (a CNS effect). Independent variable: concentration of caffeine 0- 0.5% Dependant variable: this is the heart rate (BPM) Controls: 0% caffeine to check that water alone does not have an effect on the heart rate compared to pond water. Other fixed/controlled variables: The temperature must always stay constant this means that it must be fixed at room temperature. This can be done by removing the light source from the microscope when not counting because it increases the temperature which leads to an increase in metabolism and therefore an increase in the
Mendel: Extra Biology Credit
Dear Dad, I've been in the Monastary discoving the basic of genetics. I've been experimenting with my garden peas for the past couple of years. The organisms that are used as the original mating in an experiment (tall and short plant) are called the parental generation in abbreviation is the P generation which stands for parent. When I mated the two offsprings in the p generation, the offsprings are in the F1 generation. When I breed the F1 generation I ended up with the F2 generation. For the F1 generation I selected a six foot pea plant and a short pea plant and crossed them. In the F1 generation I noticed that all the offspring were tall and didin't even show short. In the F2 generation I crossed 2 tall pea plants and noticed that 3/4 of the offsprings were as tall as the tall plants in the P generation. I also noticed that 1/4 of the offspring were as short as the short plants in the P generation. I noticed that one trait kept disappearing in the F1 generation. I gave a capital letter to the trait which showed up in the first generation and the small letter to the trait which was hidden in the F1 generation. The trait that appeared in the F1 generation I called dominant and the traits that were hidden I called recessive. I observed that some tall plants crossed with each other showed both and tall and short offspring. I came to the conclusion that an organism may look
What effect does substrate have on respiration in yeast?
What effect does substrate have on respiration in yeast? AIM The aim of this investigation is to find out how the rate of respiration in yeast is affected when different respiratory substrates are used. Five different respiratory substrates will be used and the amount of carbon dioxide produced will be measured for each substrate. The five substrates that will be used are glucose, fructose, maltose, sucrose and lactose. HYPOTHESIS Null hypothesis, H0: There is no significant difference between the amounts of carbon dioxide produced by yeast during respiration, regardless of the respiratory substrate used. Alternate hypothesis, H1: There is a significant difference between the amounts of carbon dioxide produced by yeast during respiration, depending on the respiratory substrate used. PREDICTION Natural habitat of yeast is the skin of fruit, which usually contains fructose and glucose and in some cases sucrose. Yeast is also found on malt so it is familiar with maltose as well. Therefore it will be able to secrete the enzymes needed to break down glucose, fructose, sucrose and maltose. However, lactose is present in milk and other dairy products, where yeast does not live. As a result, it is likely that yeast would not have the enzyme, lactase, needed to break down lactose. The table below shows each substrate, the enzyme needed to hydrolyse this substrate and
Case study - Outbreak of food poisoning at scientific conference.
Case Study "Outbreak of food poisoning at scientific conference" In order to investigate the outbreaks described, the following table (table 1) was presented. The table concentrate at the critical points of the outbreak. The range of onset illness was generated in the table as the incubation period of unknown micro-organism. The duration of the reported symptoms from victims was generated as the duration of illness. The temperature at which the sample was held was generated in the table as environment. Table1. Critical points of the outbreak Outbreak title Outbreak of food poisoning at scientific conference Symptoms Abdominal pain, diarrhoea, fever, nausea, vomiting Incubation period 5-48 hours Duration of illness 3-7 days Likely source of the outbreak Cooked meats (ham, roast beef, chicken) Environment 24°C Examined samples Meats left over Laboratory findings Rod, Gram -ve, facultative anaerobe From the critical points given on the table 1, it could be assumed that the micro-organisms that could be involved in this outbreak were Salmonella enterica (S. enterica), Escherichia coli (E.coli) or Campylobacter jejuni (C. jejuni). These micro-organisms are very common cause of food poisoning and they have very similar properties. They are Gram -ve rods. S. enterica and E. coli are facultative anaerobic micro-organisms and they temperature range is 10 ºC -
Making sense of data - For my Physics coursework I was given the results of an experiment.
Physics coursework - Making sense of data For my Physics coursework I was given the results of an experiment, which involved rolling two differently sized balls (initially 3 however one was marble and did not work with the light gate because it gave 2 readings as it reflected light) one small, silver, with a diameter of 0.006 m and weighing 0.00708 kg and one large, slightly rusty, with a diameter of 0.011 m and weighing 0.01672 kg, down a ramp from different heights and measuring the velocity they travelled at using a light gate, connected to a computer which worked out how long the light beam was broken for. The diagram bellow shows how the experiment was set up: I then had to decided what I was going to use these results for, I decided that I would use them to see if the height the ball is dropped from effects the amount of energy change by working out the difference of potential energy and kinetic energy of the ball. This would mean I would have the amount of energy at the start from calculating potential energy, then the amount of energy at the end of rolling it down the ramp by calculating kinetic energy. I could then find the amount of energy change by subtracting kinetic energy from potential energy. I will calculate the potential and kinetic energy from the mean of 3 tests per experiment. To calculate potential energy I will use the formula: PE = mass (kg) x
How plants have adapted or become acclimated to shade conditons.
Noreen Mc Quaid U5400636 TMA 05 Question 2 HOW PLANTS HAVE ADAPTED OR BECOME ACCLIMATED TO SHADE CONDITIONS. Conditions of shade present low average light intensity for plants, along with a difference in the quality of light (in terms of the numbers of quanta of different wavelengths). Shade light contains more far-red and infra-red quanta and fewer quanta in the range 400 - 680nm. Additionally, light quality and quantity can vary enormously and rapidly due to the occurrence of sunflecks, (a valuable source of light, yet potentially damaging.) Adaptation to shade conditions can be determined genetically or be due to acclimation. Obligate shade plants have evolved genetically to exist in permanent shade and cannot acclimate to long-term levels of high light intensity. However there are plants that show an element of phenotypic plasticity and can acclimate to low (and others to high) light intensities. * Shade plants can absorb and utilize low light intensities more efficiently than sun plants; they have a lower light compensation point and achieve net carbon fixation at lower light fluxes. It is their structural and biochemical characteristics which facilitate these properties. * At a structural level, shade plants have thinner leaves, with a shallow layer of palisade mesophyll and patchy spongy mesophyll containing more air spaces. They have fewer cells per unit area
World distribution and economic effects of AIDS
AIDS - Acquired immune deficiency syndrome World distribution and economic effects of AIDS AIDS was first diagnosed in the USA and although now a world wide pandemic, the main extent of the AIDS problem is concentrated in the continent of Africa, especially south of the Sahara desert. In 2004 30 million Africans were infected and living with AIDS, it is estimated that up to a third of central African are infected with the virus HIV. In other parts of the world the AIDS problem at this time is not so severe however the virus is spreading rapidly, especially in Russia and the former Soviet Union countries. In South East Asia the problem is growing the fastest, due to half the world's population living in that corner of the world. It is thought that by 2010 the AIDS problem in South East Asia will have dwarfed the problem in Africa. Currently in western MEDC countries the percentage of populations with AIDS is low in comparison and the percentage with AIDS is generally concentrated in needle injecting drug users and homosexuals. This lower infection rate is generally due to education, prevention schemes that cannot be afforded in other less wealthy countries and the availability of protective contraceptive methods. The main impact of AIDS in African countries is the reversal of much needed development. It is generally the working population that are being wiped out by AIDS
The negative portrayal of genetic advancements.
The Negative Portrayal of Genetic Advancements Every day scientists get one step closer to unraveling our genetic sequence. While this sounds beneficial, technology undoubtedly has a dark side as well. There is no denying the fact that science has extended and improved the lives of many, but it has also depersonalized them. People are often classified according to their disorders rather than their personalities or names. Furthermore, ethics and questions of morality must be addressed in order to handle some of the sticky issues that are created as a result of such advancements. Until recently, the topic of genetics has been practically non-existent. However, now procedures such as prenatal genetic screening have gone from occasional to routine (nine out of ten women usually have it).i Furthermore, this procedure that is "already designated as a "ritual" of pregnancy, at least for white, middle-class women in North America, is the most widespread application of genetic technology to humans today."ii Fields such as bio-ethics have been spawned from such practices, and medical journals and textbooks have been published to educate. But the information is by no means geared towards the common person. Instead, these resources have a very limited audience of those educated in the field in question. Therefore, the general public is unable to learn or keep up with the
Daphnia experimentation
The effect of Caffeine on the heart rate Aim: To investigate the effect of caffeine on the heart rate of Daphnia (water fleas). Background Knowledge: Daphnia are tiny water fleas with an average size of less than 3mm. Daphnia are translucent invertebrates (have no backbone) and their outer body is made up of a hard shell which protects the whole body except for the head. Daphnia's are found in ponds, lakes, and calm streams where the temperature is between 21-24°C (68-71°F). Daphnia reproduce rapidly. Up to 13 billion related offspring can occur within 60 days for one Daphnia. In winter the eggs are thick-shelled and thin shelled in the summer. In warmer temperatures the eggs will hatch female, and in colder temperatures the eggs will be male. Daphnia's will be used to experiment the on as although they are tiny in size their heart beat can be examined through a microscope because of their transparency. Caffeine is produced by plants as an insecticide. Cocoa in South America, coffee in Africa and tea in Asia has all been used for hundreds of years to produce "pick me up" drinks containing caffeine. These days, caffeine is used as a flavour enhancer in a wide range of cola and other soft drinks. In addition, it has medicinal uses in aspirin preparation, and is found in weight-loss drugs and as a stimulant in students' exam-time favourites like Pro-plus and Red Bull.
This is an experiment to investigate how temperature effects the respiration rate in maggots.
Investigating the effect of temperature in respiration in maggots. Aim: This is an experiment to investigate how temperature effects the respiration rate in maggots. The formula: The simple formula of respiration is: C6H12O6 + 6O2 6H2O + 6CO2 + ENERGY GLUCOSE + OXYGEN WATER + CARBON + ENERGY DIOXIDE The Collins concise English dictionary explains that respiration is 'the processes by which a living organism...takes in oxygen, distributes and utilizes it in oxidation, and gives off products, esp. carbon dioxide'. Background information: Respiration is the chemical process of releasing energy from organic compounds in living cells. The organic molecules are broken down through a series of steps to act as fuel. The most common organic compound for most cells is glucose however, some cells can break down fatty acids, glycerol, and amino acids in respiration. The energy gained from respiration is used to synthesise ATP (adenosine triphosphate) which is required throughout the body, in order to replenish ATP stores. There are two types of respiration; anaerobic and aerobic. Aerobic respiration occurs when oxygen is freely available, whilst anaerobic respiration occurs when free oxygen is not present, and the process is altered. We will investigate aerobic respiration. There are four main stages of respiration (when breaking down
