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International Baccalaureate: Biology

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    Osmosis Internal Assessment (Biology)

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    to the area of lower water concentration (potato cell). However, as the duration given for osmosis to occur increases, the volume of fluid in the cell will increase as water continually enters the cell, increasing its turgidity (when pressure inside the cell increases as the volume of its contents increases). Eventually, the cell wall will be stretched to the maximum, achieving full turgor, which will then force water back out of the cell due to the high pressure within the cell.

    • Word count: 2612
  2. Stimuli and Response. Investigation Question: How do different tempos of music affect response time (tested by Response Timer app[1]) and performance quality in students during the game of Temple Run[

    After 1 minute, I will continue to play the music, but I will test their response time in the app, Response Timer and record the data. 5. After recording the student's response time, the student will then proceed to play Temple Run, and I will record the score, distance and amount of coins collected for that play. This will be the data for the performance quality. 6. Repeat the steps for each song 7. Repeat the procedure for each student.

    • Word count: 2683
  3. Testing the solute concentration of potato cells

    Those components basically include phospholipid bilayer, integral protein, peripheral protein, glycoprotein, and cholesterol (Clegg, 2007). Phospholipid bilayer means that lipid with phosphate head is two. This has hydrophilic phosphate heads adjacent to the cytoplasm and extracellular fluid which contains water and hydrophobic hydrocarbon tails protected from the water, being 'sandwiched' in between. Proteins among the membrane are very significant. Together with the dual nature of phospholipid bilayer, they assist control the exit and entry of substances out of and to the cell. They can act as transporting electrons, binding hormones, and providing channels (Clegg, 2007).

    • Word count: 2913
  4. IB Biology notes on infection and the body's responses.

    results in redness and increase in temperature ii. Swelling from escaped fluid and proteins occurs iii. A protein called bradykinin stimulates nerve endings resulting in the sensation of pain d. neutrophils and monocytes move to the site of injury by squeezing through the capillary wall i. neutrophils phagocytize bacteria ii. Monocytes differentiate into macrophages that phagocytize bacteria iii. Macrophages also stimulate the growth of white blood cells, especially neutrophils, by releasing a growth factor e. Inflammation can also result in fever i. inhibits the growth of microorganisms and stimulates immune cells f. Pus forms from dead neutrophils, dead cells, dead bacteria and some living white blood cells 4.

    • Word count: 2650
  5. The aim of the investigation is to find out how an increase in surrounding temperature affects the activity of the plasma cell membrane of beetroot cells.

    Variables: Type of variable: Independent Temperature - measured in �C. I will be changing the temperature by placing the different test tubes in different water baths. I will use the following temperatures: 0, 20,40,60 and 80 degrees. Dependent The percentage of absorbance (%) I will do this by using a colorimeter, as this will show me the percentage of absorbance in the samples. The dependent variable will be recorded using quantitative data instead of qualitative, this is because as we want to plot a graph, we cannot do that using qualitative data and therefore must use the appropriate type of data.

    • Word count: 2453
  6. Osmosis Investigation - effect of different strength of glucose solution on potato and apple strips.

    Volume of the glucose solution which is fixed to 20 ml. The volumes are kept constant at 20 cm3 by measuring them using a measuring cylinder at each trial. Materials: 50cm3 of 1.0 mol dm-3 glucose solution, distilled water, potato tuber, apple and filter paper. Apparatus: Boiling tube, cork borer, 15 cm ruler, razor blade, tile, 25.0 cm3 measuring cylinder, forceps, covered Petri dish, stop-watch, marking pen, labelling paper and a 50 ml beaker, 10 cm3 pipette. Data collection and processing: Quantitative data : Table 1.1: Table shows the recorded data for the initial length of the apple strips, cm and the final length of the potato strips, cm.

    • Word count: 2285
  7. How the Heart Works

    The middle layer is called the myocardium which consists of all the contracting muscles (cardiac muscles). The inner layer is called the endocardium, and the smooth inner lining is in contact with the actual blood of the heart. Endocardium is also present in the soft inner lining of blood vessels. In humans, and all other vertebrates (backbone), the heart is composed of cardiac muscle (cardiac comes from kardia, the Greek word for "heart", and literally means "related to the heart"), a special type of muscle fiber not found anywhere else in the body, and connective tissue.

    • Word count: 2950
  8. Independent Research Project Vital Lung Capacity

    Individuals with asthma have trouble breathing due to blockage of the airways. A spirometer was used in order to measure and determine the vital capacity of each of the two participant groups: individuals with asthma and individuals without asthma. Respectively, the mean vital capacity values of both these groups were calculated and compared and contrasted with each other. Based on medicinal investigation, it is hypothesized that there will be a minor difference between the average lung capacity of individuals with asthma and individuals without asthma. Confounding variables in this experiment such as the age of the subjects, the equipment used and the environmental factors in the testing situation are closely inspected to avoid any invalid results.

    • Word count: 2355
  9. Enzyme IA Biology

    when cooled. Independent Variable: Temperature of enzyme liver -Increased the liver temperature by 22�C from room temperature of the catalase solution to correlate a high temperature at 44�C -Decreasing the liver temperature by 22�C from room temperature of the catalase solution to correlate a low temperature 0�C -Increase is by 22�C because in order to reach 0�C it must be decreased by 22�C from room temperature -Begin with room temperature Dependent Variable: Amount of Oxygen produced from the liver, Hydrogen Peroxide reaction (ml)

    • Word count: 2188
  10. IB biology Respiration IA

    Since increasing time increment of exercise should require more energy, it is expected that the rate of CO2 production will increase; therefore the time it takes for BTB to change color will decrease. Research Question: What is the effect on increasing time of exercise on the rate of CO2 production? Variables: The independent variable is time spent exercising The different levels of the independent variable are 30 seconds, 60 seconds and 90 seconds The dependent variable is the time taken to change BTB color The controlled variables include type of exercise, volume of BTB, straw length, color gauged, same timer per test subject, same test subject per trial.

    • Word count: 2178
  11. ProblemWhat kind of roles the factors of pH levels and temperature have on various reaction rates. What roles inhibitors and activations play on enzymatic reactions.

    Investigating the uncatalyzed rate of decomposition, an individual was picked from the group to come in the following day and test the effect of leaving the H2O2 in room temperature for 24 hours. By comparing the results between the two, we were better able to understand the effects enzymes play in reactions. Emphasis: Data Analysis and Collection Objectives: Before doing this lab you should understand: * the general functions and activities of enzymes; * the relationship between the structure and function of enzymes; * the concept of initial reaction rates of enzymes; * how the concept of free energy relates

    • Word count: 2663
  12. Isotonic Point of Potatoes

    Using a measuring cylinder (+/- 0.05 cm3) the same volume of water will be measured out for each solution. The duration of the exposure of the potato strips to the solution. The duration of the experiment will be the same for all the samples as all the potato strips will be removed from the specified concentration solutions at the same time, thus keeping the time constant Ambient Factors All the samples are kept in an air conditioned room where the room temperature is kept constant at 27.3 Co (+/- 0.1 Co) Surface area of the potatoes (cm2) (for each solution's samples.

    • Word count: 2446
  13. Enzyme Lab

    The amount of water displaced is a result of the enzyme-catalyzed reaction. By using different concentrations of the substrate (H2O2), we are able to find out just how much a change in the concentration of substrate affects the rate of the enzyme-catalyzed reaction. Therefore, by finding out what concentration produces what results, we can apply this to instances where we may want to alter the rate of enzyme-catalyzed reactions to aid us in a way that is in our convenience. Hypothesis The higher the concentration of substrate is, the faster (more water displaced)

    • Word count: 2553
  14. Osmosis Lab

    Hypothesis The higher the concentration of salt solution in the beaker (environment outside of the semi permeable tubing), the faster the rate of osmosis will be out of the "cell". The lower the concentration of salt in the solution, the slower the rate of osmosis will be. This is due to the fact that the salt (solute) decreases the concentration of the water outside of the cell, which contains a 100% water (solvent). Water will go out of the higher concentration inside the cell and out to the lower concentration where the salt is.

    • Word count: 2432
  15. Molecular Genetics: differentiating between various molecular databases

    For this experiment, the amino acid sequences for the protein Insulin were used, mainly because these are short and easier to compare. * The type of family to which the four species belong to is also a control variable. For this experiment, the four chosen species belong to the rodent family. This will help us investigate the differences among the species of the same family. * The characteristics of the species that were compared during the experiment were a control variable.

    • Word count: 2435
  16. Pill Bug Lab

    They are also most active at night and prefer higher levels of soil, so the amount of soil they are living in could affect their activity. I collected my bugs from my family's garden in my backyard and from potting soil that I found around San Bruno park. I created the habitat I would keep them by, first, putting a moist paper two at the bottom of a plastic container. Then I put soil and a little bit of vegetation on top of that, and finally, I put the Pill bugs in their new habitat.

    • Word count: 2087
  17. DNA; Past, Present, and Future

    and prokaryotes do so in the cytoplasm. Chromatin proteins in the chromosomes compress and organize DNA, thus maneuvering the interactions between DNA and other proteins. DNA was discovered for the first time in 1869, by Swiss physician Friedrich Miescher. He discovered a microscopic substance in the cellular nuclei of the pus of discarded surgical bandages, which he named "nuclein". A short while later, in 1919, Phoebus Levene discovered the general structure of DNA; the sugar and phosphate base. Although he thought that DNA consisted of a string of nucleotides through the phosphate groups, he was incorrect in suggesting that the chain was short and the bases repetitive in a fixed manner.

    • Word count: 2564
  18. Exercise Investigation

    Thus, power walking that has more movement in these muscles than aerobics will have a larger impact on the heart. PROCEDURE The Variables Independent Variable How was it changed? Different types of Exercise By testing 5 people from Aerobics and Power Walking group. Dependent Variable How was it measured? The percentage of increase in heart beat By making the subjects to measure their heart beat before and right after exercise for 60 seconds. This will be done twice per subject so that the result is more valid.

    • Word count: 2126
  19. Bread lab. What effect will the mass of glucose added to yeast have on the rate of reaction of cellular respiration of yeast measured by the growth of bread (CO2 production).

    Mix the glucose, yeast and water in a 250 mL beaker. The amount of water is written on the package which the yeast came in. 3) In order to speed up the dissolving process, put the beaker on a hot plate and heat to a temperature of 300C indicated by a thermometer. 4) Once the sugar has been completely dissolved remove the beaker from the hot plate and allow it to cool back down to room temperature. 5) Using a weigh boat, measure 2 imperial cups of flour.

    • Word count: 2105
  20. To investigate how aerobic exercise affects the heart rate

    Every time the heart beats, it pumps a quantity of blood into our circulatory system. These beats cause a shock wave (pulse) which travels along the walls of the arteries. This pulse can be felt in several parts of the body1. In this experiment, an automatic blood pressure monitor is used on the arm to measure the pulse of the test subject. A person performing physical activity would require a higher demand for energy. In order to get more energy, respiration needs to be increased. This means that a greater amount of oxygen and glucose is required by the body which can be obtained by increasing the rate of breathing so more oxygen can enter into the system.

    • Word count: 2553
  21. Determining the rate of action of an enzyme

    The Hydrogen Peroxide breaks down to form water and oxygen. This reaction can be seen below: 2H2O2(l) --> 2H2O(l) + O2(g) The Catalase molecules are extremely effective as one molecule of the enzymes can interact with six million molecules of hydrogen peroxide in one minute. Hypothesis: It is hypothesised that the rate of action of the Catalase will increase proportionally with the increase of surface area. This is based on the surface area to volume ratio; by having a higher surface area to volume ratio it will in turn allow more substrate to react with the available enzyme's active sites until a plateau is reached in the reaction rates where the maximum number of active sites are being bound to by substrates.

    • Word count: 2630
  22. The effect of antibacterial toothpastes on Micrococcus luteus

    The zone of inhibition is measured using digital callipers. Control of variables * The volumes of toothpaste are controlled by using a cylinder to cut out pieces of the agar * The volume of agar in plates was measured and the same amount of agar was put in each plate (by a professional) * The bacteria in each plate was distributed equally (this was controlled by a professional). * The temperature of the plates was maintained during the investigation by keeping the plates in an incubator.

    • Word count: 2222
  23. Rate of heat loss

    Evaporation of water (for instance in perspiration) from the body surface speeds up the rate of cooling. This is because evaporating particles need energy to overcome the intermolecular forces to escape from the surface. They gain this energy by absorbing it from the body surface, making it lose heat. Therefore the loss of water in the form of sweating increases the rate of heat loss from the body surface. 4. Huddling together in groups keeps bodies (frequently animals) warmer than isolated and single bodies.

    • Word count: 2201
  24. Plant Tropism Lab

    Record data from each day on data table 4. On the 10th day of the experiment, rotate the plastic bags holding the beans 90 degrees counter clockwise, make observations and measurements on bean growth the next day 5. On the 12th day of the experiment, rotate the beans a further 90 degrees counter clockwise, making it 180 degrees from its original position. Make observations and measurements on bean growth the next day DATA COLLECTION & PROCESSING Aspect 1: Recording Raw Data: Qualitative observations: (Group "3 Guys and Vlad) March 3: No growth. (Day 1) March 4: No growth. (Day 2)

    • Word count: 2965
  25. Biology Scientific Events

    Also it creates opportunities to construct more DNA-like molecules that has the ability to store information. The capability to modify DNA's structural characteristics could gives nanotechnologist more control as a material for engineering. It is more evidence of how technologically advanced our world is becoming. Works Cited Barry, Patrick. "DNA, Jim, but not as we know it." Science News 2 Aug. 2008: 15. Current Events November 17, 2008 The Promise and Power of RNA This article talks about the discovery of RNA interference against the production of the protein PCSK9 that causes the body to have high levels of cholesterol.

    • Word count: 2451

IB Biology is the study of living organisms. The four basic concepts which run through the course are: evolution, equilibrium within systems, universality versus diversity, and structure and function. These concepts give the student a strong foundation upon which other detailed knowledge can be built. You will also be completing a significant amount of practical work and an experimental approach is strongly emphasised.

Assessment is both externally and internally organised. The external examinations are a mixture of multiple-choice, short answer and extended answer tests.The extended answer examinations require you express yourself in a concise and scientific manner and some great examples of these IB Biology essays can be found on Marked by Teachers. Science can bring enormous benefits to societies and you will be encouraged to become a responsible and ethically minded scientist.


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