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International Baccalaureate: Biology

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  1. Bio lab - Oxygen Consumption in germinating and non-germinating seeds

    10 seeds were placed in the test tubes and a layer of non-absorbent cotton was placed on top of the KOH solution cotton. 5. For equal volume, beads were added to each of the test tubes with the dormant seeds since dry peas take up less space than the same quantity of germinating peas. The test tubes were capped with the stopper fitted with a pipette, tip pointing outwards. 6. The pipette was put into the water to find out the consumption of the oxygen.

    • Word count: 6392
  2. Biology Lan - factors affecting enzyme activity

    - Hydrogen peroxide (3% solution) - Forceps - Trough - Graduated cylinder - beakers (5) - test tubes (5) - thermometer (5) - clock - tube with rubber stopper - Hot plate - Ice cubes Procedure: All the materials were gathered to start the experiment. All the beakers were filled up with water in order to adjust the temperature. Catalase was filled into five tubes and the trough and the graduated cylinder were filled up with water to prepare for the experiment. Five thermometers were put into each beaker to keep track of the temperature.

    • Word count: 2636
  3. Lab 2 : Microscopy OBJECTIVES Describe how to care for a compound light microscope Recognize and give the function of the parts of a compound light microscope Accurately align a compound light microscope

    The course knob is then adjusted by turning it both ways. When the knob is turned in an anti-clockwise direction, the stage moves downwards; however when the knob is clockwise, the stage moves upwards. 5. next , using the eyepiece , the course adjustment knob is focused on a letter 6. As the letter 'I' was observed under the low magnification, the image seems to be inverted. Moving the slide to the left makes the image move right and vice versa. The image is then centered once again and then when the slide moves away, the image moves forward.

    • Word count: 850
  4. Ecology Open Investigation Does the geographic location affect the biotic and abiotic factors in Brown Lake and 18 Mile Swamp located at North Stradbroke Island.

    [3] Beside the swamp is a four wheel drive track that extends from the Causeway. This track was built for vehicles. Because Brown Lake and 18 Mile Swamp is located in different parts of the island, in this investigation, biotic and abiotic features of Brown Lake and 18 Mile Swamp will be compared to see if the geographical location affect the features of the site. Abiotic features such as colour, turbidity, oxygen levels, pH level, salinity, nitrites, nitrates and temperature will be sampled and tested in this investigation.

    • Word count: 6399
  5. Lung Capacity Fitness Level

    [6] Vital Capacity = IRV (inspiration) + ERV (expiration) Diagram 1.1: Graph showing the different breathing activities [7] There are several factors which affect one's potential lung capacity. Factors such as: * Gender - as males have larger lung capacity than females * Height of person - the taller the person is the tendency that they will have a larger lunch capacity then a shorter height person * Smoking - smoking damages the lungs and slowly diminishes its functions thus causing the lungs to become weaker * Exercise - athletes have a larger lung capacity then non-athletes * Breathing illnesses - eg; asthma can affect one's breathing activity as the lungs are weak and have difficulty handling rapid changes in physical breathing activity (such as sprinting)

    • Word count: 6468
  6. Allelopathy. Open Investigation Will increasing the number of allelopathic sunflower plants effect the height growth of a non-allelopathic bean plant when the two types of plants are grown next to one another?

    * Reduce the ability of plants to compete with allelopathic plants which are excreting the chemicals Plants that are under stress from such things as the existence of pests and diseases, less than optimum access to nutrients, sun or moisture, possess a higher risk of being eliminated by allelopathic plants. Diagram 1.1: Plant external structure [8] Allelopathic chemicals can be released from any part of the plant, it merely depends of what type of plant it is. Allelochemicals can be released from can plants' leaves, flowers, roots, fruits, or stems.

    • Word count: 7463
  7. Stem Cell Reflection

    By researching these stem cells, humans will no longer be at risk. We will be able to have organs and limbs grown from scratch rather than having a donor. The con side said that religious figures claim that the use of stem cell research would be immoral and would be playing "God". They feel that only God can determine how long one should live, or how they should die. They claim that by using stem cells, scientists would be altering the lives of humans and sinning.

    • Word count: 1005
  8. Outline the control of the heart beat in terms of myogenic muscle contraction, the role of the pacemaker, nerves, the medulla of the brain, epinephrine (adrenaline)

    In the atrial systole the blood is squeezed from the contracting atria into the relaxing ventricles. In the ventricle systole the ventricles contract and pump the blood out of the heart whereas the atria relax and refill. In the diastole the whole heart is relaxed and it refills. The frequency of the cardiac cycle is called heart rate. A normal adult should have a heart rate of 70bpm when in rest. The heart has an own inherent rhythm, that means that the heart muscle, the cardiac muscle, contracts myogenic. This is an independent of external nervous stimulations rhythmic contraction of the cardiac muscle, which is unique for its branched interconnection.

    • Word count: 996
  9. Structure and functions of the human brain

    Pituitary gland: The pituitary gland is made up of two parts: the anterior pituitary gland and the posterior pituitary gland. The anterior pituitary gland consists of endocrine tissue and secretes hormones like FSH, LH, GH ect. These hormones produced in the anterior pituitary gland are released after a stimulus given from the hypothalamus in the form of neurosecretions and control and regulate many body functions. The posterior pituitary gland does not produce hormones but stores those produced in the hypothalamus.

    • Word count: 1013
  10. I.V.F. stands for In Vitro Fertilisation and is also known as the Test-Tube Baby technique. In this process the egg cell is fertilised by the sperm outside the womb, in vitro, and then artificially implanted in the uterus.

    34-36 hours after this injection the egg cells are aspirated from the ovaries. Aspiration is performed with a very thin needle through the vagina wall. Usually 10-30 eggs can be removed by this method. In the laboratory the removed eggs and the sperms are prepared for fertilisation and then incubated together for about 18 hours. After this time the eggs are usually fertilised but they are not yet ready to be implanted into the mother. The fertilised eggs are left in a special growth medium until they have reached the 6-8 cell stage.

    • Word count: 654
  11. Biodiversity of Ethiopian Forest

    The older the area being assessed the more diverse the species will be. Variables * Old plantation (120 years old) * Young Plantation (60 years old) * Natural Forest A (500 years old) * Natural Forest B (500 years old) Method We looked at four different areas in the Menagesha forest. As mentioned before a twenty by twenty meter area was assessed in each case. One person stood at each corner of the square and the other people were made to count the different species that inhibit the area and the number of species.

    • Word count: 790
  12. The biodiversity of Warai woods, Warai river and Dixel Lake. Observing the flora and fauna in different ecosystems and determining the biotic and abiotic factors influencing them.

    But if there was a higher biodiversity in that area, even though mosquitoes were isolated from that area, lizards would still have a chance to feed on flies and other insects and hence they would survive thus keeping the ecosystem in a more stable condition. Hence the stability of the ecosystem and the survival of its species depends on the biodiversity of the species. You could use the Simpson's diversity index to calculate the biodiversity of an ecosystem, where greater the index, the greater the biodiversity.

    • Word count: 778
  13. Missin carbon footprints

    "There is good evidence that the missing carbon went north of the equator. A much higher volume of carbon dioxide is released in the northern hemisphere, but the concentration of carbon dioxide is the same in the northern hemisphere as it is in the southern hemisphere. 4. How can tree-ring data be used to provide evidence of the changing atmospheric carbon dioxide concentrations? Trees absorb carbon dioxide through photosynthesis and convert the carbon dioxide into wood. A trees' growth is shown through its annual rings, with the width of ring indicating the amount of growth.

    • Word count: 562
  14. Energy Audit

    225.26 6757.8 31166.80 PYP. Admin 267.52 5885.35 48152.88 Dp block- 1st , 2nd floor 444.70 9783.29 80045.10 Hostel, road 439.24 966.28 79063.20 All areas combined: Total energy used per day: 1896.96 kWh Total energy used per month: 35358.40 kWh Total energy used per year: 612573.31 kWh Graph to show the contrast between the energy used per day in different areas: Chart 1: Graph to show how much energy is used by each appliance: Chart 2: Graph to show how much energy an AC consumes in one day: Chart 3: Money saved in on a day when AC's were not used:

    • Word count: 1941
  15. Heart rate deisgn

    Hydration Failing to stay hydrated can result in an increase in heart rate7 9. Lack of sleep Lack of sleep causes tiredness and annoyance, heart rate rises8 10. High Bp Hypertension is due to high heart rate9 11. Age Older person, higher heart rate10 12. Gender Male have higher heart rate10 13. Smoking status Tobacco addiction causes hypertension, due to higher heart rate11 14. Activity of thyroid gland Overactivity of thyroid gland rises heart rate12 15. Height of a person Smaller people have higher heart rate than average adults13 Possible effect on heart rate 16.

    • Word count: 1063
  16. How pH effects enzyme Catalase in potato cells

    Factors that influence the catalytic activity of enzymes and how to control them: 1. Temperature is known to have the most influence on catalytic activities. As temperature rises, more energy is transferred to the molecules, giving them more kinetic energy, increasing the chance of successful collision1, and so influencing the rate. However, too high temperature can cause too much energy and the molecules will be damaged by the vibration. To prevent this factor influencing the data, the experiment will be taken in the same environment (biology laboratory). Due to the limited time and equipment, this factor cannot be entirely controlled, so I do expect there to be slight differences in temperature at different times of experimentation.

    • Word count: 2485
  17. The effect of temperature on membrane stability

    The amount of water to increase the temperature of the beetroot. When the membrane breaks down, the substances will diffuse in the water, so the water must be the same amount used in each experiment. The time the beetroot is warmed by the water. There must be a time for the beetroot to be in the water for this will affect the colour intensity and influence the results. The aperture used on the colorimeter. It must not change when measuring the colour intensity.

    • Word count: 1574
  18. The effect on osmosis on the egg shell

    VARIABLES Apparatus Units Range INDEPENDENT VARIABLE 1. Different concentration of salt solution - [%] 0-10 % DEPENDENT VARIABLE 1. Mass change of eggs* Electronic balance [g] [�0.01 g] *thanks to this, indirectly mass change In eggs will be measured Possible effect(s) on result UNCONTROLLED VARIABLE 1. Size of air cell inside the egg It affects degree of egg's immersion and may affect process of osmosis as it reduces contact surface between surrounding and content of egg (which is separated by semi-permeable membrane 2.

    • Word count: 3500
  19. Environmental systems revision notes

    N= the total number of organisms of all species n= the total number of organism of a particular species. Measuring abiotic factors Acuatic ecosystem: ph (water acidity, PH meter or litmus paper), salinity (hydrometer), Temperature (determines soluvility of oxygen, thermometer), dissolved oxygen (oxygen sensor), flow velosity (impellor measure), turbidity(cloudiness of water, nephelometric). Terrestial ecosystem: temperature (thermometer), light intensity (footcandle meter), wind (anemometer), mineral content (important for soil water holding capacity), particle size, slope (use water in a bottle). Using Biological Dichotomous keys Biological keys: groups of organisms that have several characteristics (invertebrates). Dichotomous keys: helps the scientists to identify stuff in nature by asking simple yes/no questions.

    • Word count: 730
  20. FOOD LAB Purpose: To test food and beverages to find its chemical properties

    For flour-Mix small amount of flour with distilled water to make a 'flour' solution 8. Add in chemicals Iodine - Add a few drops of the iodine solution to the solution (positive result - dark purple color) Benedicts solution - Add 5mL of benedict's solution to 8 drops of unknown solution in a test tube. Place the test tube in a boiling water bath for 5 minute. (positive result - yellow) Paper Test (pH Level) - Drop a small amount of the food or beverage on the pH paper and match the color change with the chart on the bottle to find its pH level.

    • Word count: 1255
  21. Aim: To observe the orientation response of fly larvae (maggots) to light. Hypothesis: Fly larvae are photophobic and tend to move from light to darkness.

    3. 10 maggots were placed on the light half of the tray and start the stopwatch. The distribution of maggots over dark and light areas was recorded over a period of three minutes. 4. The procedure was repeated (using other maggots) 10 times. 5. The data was recorded as following. Results: Table 1: The distribution of maggots over fly larvae Number of maggots in the light half � 0 Number of maggots in the dark half � 0 1 9 2 8 2 8 2 8 5 5 3 7 1 9 4 6 4 6 2 8 Fig.1: Depicting the proportion of maggots which exhibited a negative phototaxis (74%)

    • Word count: 486
  22. Germination lab experiment

    This continues until enough leaves get matured to produce through photosynthesis faster than it is used for growth. In this picture you can see the process of germination Requirements for the process of germination: ==> Water - It is required to make the seed burst and break the seed coat and it is also needed to moisten the seed. ==> Oxygen - It provides the seed with metabolism. ==> Temperature - It effects the growth rate and cellular metabolic. ==> Light or darkness- needed for growth and energy. Aim To answer the research question. Research question How does the change in salinity affect the process of germination of a seed?

    • Word count: 1988
  23. Reaction Time

    Introduction To be able to participate in certain sports activities one needs to, to some extent, be fit. Strength, endurance, flexibility, balance and agility are some of the factors which might decide who wins a game of some sport. Another factor that contributes to having an advantage in sports is a fast reaction time. Reaction time is the time between a stimulus and the beginning of the reaction to given stimulus.1 The time to respond to the stimuli, which is the time it takes to carry out an action or the movement speed to carry out the reaction, is not included in the reaction time.

    • Word count: 5267
  24. Biology Industrial Melanism of Peppered Moth Lab

    8. Materials were returned to where they belong Data Collection and Processing Raw Data Tables Table 1. Number of Melanic Moths and Light-Coloured Moths left on Light-Coloured "Tree Bark" Trial Number Number of Melanic Moths Number of Light-Coloured Moths 1 13 17 2 11 19 3 7 23 4 3 27 5 1 29 Table 2. Number of Melanic Moths and Light-Coloured Moths left on Light-Coloured "Tree Bark" Trial Number Number of Melanic Moths Number of Light-Coloured Moths 1 11 19 2 10 20 3 7 23 4 6 24 5 6 24 Table 3. Number of Melanic Moths and Light-Coloured Moths left on Light-Coloured "Tree Bark" Trial Number Number of Melanic Moths Number of Light-Coloured Moths 1 12 18 2 9 21 3 7 23 4 10 20 5 8 22 Table 4.

    • Word count: 4182
  25. Continuous and discontinuous variation in ivy. Width and lenght (in centimeters) of 16 ivy leaves (Hedera sp.) were measured and raw presented in Table 1. The leaves were obtained at four different locations in Maribor, shown in the table.

    5 6 4,9 6,5 7 5 6 7 9,3 5,5 7,4 8 7,3 8 4,9 5,5 4,3 5,9 5 6,5 6,9 7,1 9 7,2 9,1 5,9 9,2 5 6 6,8 8 10 6,3 6,6 5,2 7 6,7 9 8,4 7,4 11 6,6 8,3 4,5 7,1 4,5 6,8 7,6 7,9 12 6,5 7,3 4,6 5,6 8 10 7 7,8 13 6,4 7,3 3,9 5,2 5,1 7,4 5,2 6,4 14 6,5 7,5 5,6 7,5 5,2 7 8,7 9,8 15 6,4 8,1 3,8 6 4 5,4 5,5 5,9 16 5,2 5,5 4,2 5,2 6,5 9,3 8,9 9,9 Table 1 - Measurements (width and lenght)

    • Word count: 636

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