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International Baccalaureate: Biology

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  1. Carrot growth with differing wavelegnths of light

    White light is a combination of all visible colors giving it a wavelength range of 400-700 nm. Even though the plant reflects much of the green light, some photosynthesis still occurs in this range (Allot 2007). While chlorophyll is the main light absorber in the plant, accessory pigments are able to absorb wavelengths that chlorophyll cannot (Allot 2007). Photosynthesis is a process involving much more than pure light absorption. After the chlorophyll absorbs light energy, an electron in the chlorophyll molecule is raised to a higher energy level and is referred to as excited and photoactivated (Allot 2007).

    • Word count: 3107
  2. Osmotic Concentration Lab: Abstract (Design)

    This gives us an indirect way to measure the osmotic concentration within living cells, in this case, plant cells. In this laboratory activity I will investigate the processes of osmosis in a model of a semi-permeable membrane system. I will also investigate the effect of solute concentration on percent change in mass as it relates to living plant tissues. B. Hypothesis If the percent change in mass of carrot cells is related to solute (sucrose) concentration then as the concentration of solute (sucrose) is increased, the mass of the carrot will decrease thus demonstrating an inversely proportional relationship. C.

    • Word count: 886
  3. Drosophila Lab: Eye Color

    Variables: Independent Variable: Phenotype and Genotype for the Eye Color of Drosophila parents (wild type red vs. white) Dependent Variable: Phenotype and Genotype for Eye Color of Drosophila offspring Constants: Other Phenotypes and Genotypes including: body type, bristles, antennae, eye shape, wing size, wing shape, wing vein, and wing angle; room temperature; temperature of the incubator; duration of incubation. Method (Procedure): Materials: Male White-eyed Drosophila (fruit fly), Female wild-type red-eyed Drosophila (fruit fly), Beakers(6), Incubator, Cork stopper (6), Microscope, Sorting Brush, Slide, Ether, Calendar, Computer Procedure: 1. Obtain a vial of wild- type flies. Practice immobilizing and sexing these flies.

    • Word count: 1743
  4. Biodiversity loss

    Biodiversity plays a huge impact on our daily lives even though many of us don't recognize it. It affects us from the foods we eat to the clothes we wear to the medicine we use. There are about 1.4 million discovered species and another 10 to 20 million yet undiscovered species. These organisms might hold the key to many of the world's problems. Even the smallest microbes and bacteria are responsible for transforming waste to useful products. Unfortunately human activity has been threatening biodiversity and has already left its marks. Losing one species can have a ripple effect where all the other organisms' dependant on the endangered organism can face a serious threat of extinction.

    • Word count: 857
  5. Lab Enzymes Activity

    Hypothesis: As amylase is secreted in saliva and pH of saliva is 7,0 pH we assume that this value of pH is an optimal value for the activity of this enzyme. The amylase therefore will best digest starch when pH is neutral (7,0 pH) - when no acidic or basic solution is added. Planned method: In the examination usage of substances of different pH is planned. To obtain: - acidic solution: 0,1 mol of HCl will be prepared - basic solution: 0,1 mol of NaOH will be prepared.

    • Word count: 823
  6. Design Activity Enzymes

    Lactose (also called milk sugar) is a disaccharide found in milk only, and is an important source of energy for young mammals. Lactase, secreted by mucosa and active in microvilli of epithelium of small intestine, with an optimum pH of 8.5 is an enzyme which breaks lactose into glucose and galactose. Method and equipment: In this experiment we are going to prepare 14 trials of lactase with lactose. In order to do that, we will need the following: - a bottle of pills of enzyme lactase (can be bought at pharmacy)

    • Word count: 501
  7. Reciprocal Altruism in Vampire Bats

    � Reciprocal altruism - altruistic behaviour appears generally towards members of the same species rather than close relatives. Vampire bats are example of mammals that show altruistic behaviour. They share food (in this case blood) with other bats without any benefits for themselves. True reciprocal altruism is very rare. In most cases altruism is a combination of kin selection and other forms of cooperation. Reciprocal altruism is described as when one animal acts for the benefit of another animal and in doing so decreases its own fitness.

    • Word count: 514
  8. Plant Lab. What effect does the amount of light have on the growth of a bean plant measured by the height of the bean plant?

    In a plant growing in the dark the chlorophyll will slowly be destroyed causing them to use their food reserves. Once the reserves have been used the plant will die. This is what happens in plants that are not grown in sunlight. Etiolating is a phenomenon that occurs in plants not being grown in sunlight, where the stem of the plant rapidly elongates to increase the probability of the plant finding light. In order to carry out this etiolation the plant must use its food reserves, so if the plant does not find light having used these reserves, it will die seen there is no useable energy for the cells of the plant to grow.

    • Word count: 2375
  9. What effect will a change in temperature of hydrogen peroxide (C) have on the activity of the enzyme Catalase in potatoes measured by the height of the bubbles created by the reaction in a test tube?

    The exact formula of this breakdown is shown here. In a catabolic reaction, the enzyme molecule can bind with more molecules of substrate. Each enzyme may multiple times. The Substrate molecule fits into the active site of the enzyme. The active site splits the substrate molecule into smaller molecules. The substrate molecule can now reacts to form the product of two smaller molecules, which exit the active site. Temperature affects the activity of enzymes since an increase temperature speeds up the movement of substrate molecules, so that when they collide with the enzyme they have more energy and are more likely to bind with the active site speeding up the reaction more.

    • Word count: 2016
  10. Free essay

    Effect of Nitrate Concentration on Plant Growth

    9 (9 grey) 26 (4 grey) 6 (6 grey) Day 9 25 (5 grey) 5 (5 grey) 30 (18 grey) 9 (9 grey) 12 (3 grey) 14 (10 grey) 32 (4 grey) 9 (4 grey) 34 (9 grey) 8 (6 grey) Day 10 19 (5 grey) 5 (5 grey) 28 (9 grey) 9 (11 grey) 11 (7 grey) 7 (4 grey) 32 (9 grey) 9 (9 grey) 28 (8 grey, with bug) 8 (6 grey) Relationship Between 10mg/ml Nitrate Concentration and the Growth of Duckweed 10 mg/ml (�1) Nitrate Concentration Beaker 1 Beaker 2 Beaker 3 Beaker 4 Beaker 5 Beaker 6 Beaker 7 Beaker 8 Beaker 9 Beaker 10 Day 0 6 6 6 6 6

    • Word count: 3094
  11. Digestion Lab discussion

    For test tube 1, one scoop of pancreatin powder was added, a few drops of distilled water was added to test tube 2 and both were placed in a 37-40�C incubator for 45 minutes. The conditions for the absorption in the small intestine included the equal addition of starch solution and glucose solution to the dialysis tubing in which it was submerged in distilled water. Then 20 drops of Benedict's solution was added to the vial in which it was then placed in boiling water.

    • Word count: 1211
  12. biology extended essay - How different diets: vegetarian, vegan and a meat centered diet has an effect on the health in areas like weight, blood pressure, body mass index and how often you get sick(common cold).

    this was seen by the number of people that claimed to be vegetarian and the increase in published literature promoting the health benefits of vegetarian diets.[1] Becoming a vegetarian, vegan and non vegetarians (meat eaters) can all be resonable alternatives for health if intelligent practices such as making sure your diet is balanced are followed and if certain principles of healthy eating and lifestyle are payed attention to. Many people practicing different diets tend to pay more attention on the positive sides than the negative sides of adapting a diet, that is why I decided to investigate how the weight

    • Word count: 5300
  13. Biology Internal Assessment Peas Lab

    7.) Once you have seen a temperature change in both flasks, open the flasks and observe their contents. Observe and notice if either of the flasks have peas that have sprouted and if either of the flasks have peas that have begun to decompose (ferment). Results Temperature (+/- 0,5 �C) Days Morning 8:10 Evening 4:10 Boiled Peas Not-boiled Peas Boiled Peas Not-boiled Peas Week-1 Monday 25,0 25,0 Tuesday 24,0 25,5 24,0 26,0 Wednesday 24,0 25,5 24,5 26,0 Thursday 26,0 26,0 25,5 26,0 Friday 24,0 26,0 24,5 26,0 Saturday - - 24,0 26,0 Sunday 23,0 24,0 - - Data Processing After gathering all of my data together, I divided them in 2 different sections.

    • Word count: 1221
  14. Biology Internal Assessment Soil pH

    5.) Collect the soil that is 5 meters away from water. In order to collect dry soil: 1.) Collect the soil that is 11 meters away from water. 2.) Collect the soil that is 12 meters away from water. 3.) Collect the soil that is 13 meters away from water. 4.) Collect the soil that is 14 meters away from water. 5.) Collect the soil that is 15 meters away from water. Method 1.) Collect all the apparatus listed above. 2.) Locate a relatively dry spot (>10m) and a spot close to water (<5m) using a meter stick for both cases.

    • Word count: 1355
  15. The impact of external factors: water and the carbon dioxide on the rate of photosynthesis.

    Photosynthesis demands also a free energy taken from the sunlight that falls on the plant. After that, chlorophyll which is a green chemical substance contained in chloroplasts, in green parts of the plant, enables to trap it and use in the further process. Those organelles are filled with a matrix, called stroma and inside stroma there are membranes - thylakoids where photosynthetic pigments can be found. Thylakoids are grouped in grana. Photosynthesis requires two steps: a) the light-dependent stage in which the light energy is used to make high-energy molecules b) and the light-independent stage in which a carbohydrate is produced.

    • Word count: 733
  16. Virtual Genetic Lab

    Parents: Blue Male (1) x Blue Female (1) gave offspring: Cage 2: 15 Blue Males; 22 Blue Females. Parents: Pink Male (1) x Pink Female (1) gave offspring: Cage 3: 19 Pink Males; 19 Pink Females. Parents: Blue Male (1) x Pink Female (1) gave offspring: Cage 4: 14 Blue Males; 11 Blue Females. Parents: Pink Male (1) x Blue Female (1) gave offspring: Cage 5: 3 Blue Males; 3 Blue Females 9 Pink Males; 5 Pink Females. Parents: Blue Male (2) x Pink Female (3) gave offspring: Cage 6: 16 Blue Males; 17 Blue Females. Parents: Pink Male (5)

    • Word count: 2397
  17. Aim: To investigate whether the temperature effects the production of yeast and hydrogen peroxide by measuring the oxygen gas given off for each temperature.

    These variables are: Control variables: - 10ml of hydrogen peroxide - 1ml of yeast solution - Same length of time recorded for each experiment for 1 minute each to measure the bubbles produced - Temperature needs to be maintained at given temperatures Methods of keeping the control variables controlled: I will use a water bath to help maintain the desired temperature of hydrogen peroxide. If the thermometer indicates the temperature is decreasing, then I will add more hot water to the water bath in order to sustain the temperature.

    • Word count: 1452
  18. An alternative solution to environmental issues

    Before, people did not worry about some natural issue that some people are worried about in the modern world. The only problem that they could ever have was that the natural resources that were used for human consumption were not enough. This can be seen with the theory that Maltius, an important person from the English Classic Economy; he said that natural resources that people used and consume grew arithmetically, while the human population grew geometrically. In other words, he said that human population had a bigger proportion of growing than the proportion that the resources had.

    • Word count: 501
  19. Effect of Temperature on Membranes

    tube (6ml), number of discs on each needle (6 discs), time which needles are placed in water bath (1 min), time with samples are left in test tubes after being heated (20 min) Raw Data of Absorbancy Temperature ( ) Sample blank control Readings Actual Readings Average Standard Deviation Standard Error Order of redness (1 being the lightest) 30 a 0.922 -0.616 0.306 0.352 0.0657 0.0465 1 almost colourless b 0.078 0.321 0.399 40 a -0.914 1.349 0.435 0.433 0.0028 0.0020 2 b -0.012 0.443 0.431 50 a 0.006 0.481 0.487 0.471 0.0226 0.0160 3 faint pink b 0.009 0.446

    • Word count: 1014
  20. Transpiration Investigation

    in order to mitigate water loss. However, I think that overall the direct effect of increasing light intensity will result in increasing rate of transpiration. In other words the two would be expected to have a proportional relationship. Equipment * Laptop * Vernier go-link computer interface x 2 * Vernier gas pressure sensor x 1 * Philip Harris light intensity sensor * Clamp stand x 2 * Clamps x 3 * Scalpel * 100cm ruler (�0.5cm) * 100 Watt light source (lamp)

    • Word count: 4255
  21. Effects of Temperature on Enzymes

    6. Fill the burette with water and introduce into it the tube that comes from the flask bung. Invert carefully into the beaker that contains water. 7. Measure 5cm3 of hydrogen peroxide into the syringe and connect it to the flask. The H202 has to be at the same temperature as the water in the container, if the water is at 70�C, the H2O2 ha to be at 70�C as well. 8. Inject the H2O2. Immediately, start counting time with a stopwatch and record measures of the level of water in the burette every 30 seconds. 9. Repeat the experiment but now at 60�C, 50�C, 40�C and 30�C.

    • Word count: 881
  22. Design Lab - experiment to discover whether or not listening to house music affects ones heart rate.

    and the activity which that person is doing. Stronger people and athletes generally have low resting heart rates because they have more endurance. The factor that has the greatest effect on heart rate, however, is the amount of CO2 in the blood, the higher the density the faster your heart rate will go. Hypothesis: I do think that listening to house music will make a person's heart rate go up, maybe not as much as actual physical exercise does, but certainly adding a couple (5-10) more beats per minute.

    • Word count: 788
  23. G4 planning lab

    Background Knowledge: The Brick Kiln where the study was conducted was an intermittent brick kiln. In intermittent kilns, bricks are fired in batches. Generally, bricks and fuel are stacked in layers and the entire batch is fired at once, the fire is allowed to die down and the bricks allowed to cool after they have been fired. The kiln must be emptied, refilled and a new fire started for each load of bricks. In intermittent kilns, most of the heat contained in the hot flue gases, in the fired bricks and in the kiln structure is thus lost.

    • Word count: 1191
  24. Environment science lab soil planning lab

    And thus the Soil at 3 metre from road will be having the highest content of water and thus it can be said that the soil in different areas of road at a certain distance will have different soil texture, ph and water content. The pH of the soil will be basic because some vegetation was seen. Variables: 1) Controlled Variables: Time of collection of samples Method of collecting samples 2) Independent variables: Distance from the road 3) Dependent: Amount of pH, soil texture and the water content in each soil present.

    • Word count: 1872

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