• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

International Baccalaureate: Biology

Browse by
4 star+ (6)
3 star+ (10)
Word count:
fewer than 1000 (206)
1000-1999 (212)
2000-2999 (67)
3000+ (57)
Submitted within:
last month (9)
last 3 months (9)
last 6 months (10)
last 12 months (12)

Meet our team of inspirational teachers

find out about the team

Get help from 80+ teachers and hundreds of thousands of student written documents

  1. 1
  2. 2
  3. 3
  4. 4
  5. 23
  1. 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
  2. Testing the effect of characteristics of leaves on the transpiration rate of * Rubiaceae, Verbenaceae, Oleaceae, and Rutaceae

    The first stage is called photolysis. Light energy is to split water into one oxygen and two hydrogen atoms. Oxygen as waste product leaves a plant and ATP energy is also produced by absorbed light (Clegg, 2007). The second and last step is carbon fixation. In this part, carbon dioxide (CO2), hydrogen atoms from photolysis, and energy from ATP together form organic molecules of sugar, or glucose (Clegg, 2007). As mentioned before, oxygen leaves a plant. Not only oxygen but also water leaves the plant. More exactly, water evaporates from the plant mainly at leaves.

    • Word count: 4469
  3. The aim of this investigation is to examine the difference in the mass of potato after keeping the in sugar solutions of different concentrations for 24 hours. The water potential will also be calculated.

    - Paper towels - Plastic wrap Method: Step 1: Pour 100ML of sugar solution 250ML beaker. Step 2: Measure the mass of the potato cores together. Step 3: Put the potato cores into the beaker of sugar solution. Step 4: Cover the beaker with plastic wrap and allow it to stand for a 24-hour period. Step 5: After keeping the potato cores in the solution for 24 hours remove them from the beaker, blot with a paper towel, and measure the mass of the fore cores after soaking.

    • Word count: 920
  4. Enzyme Lab. pothesis: If liver and potato tissue are tested for the amount of catalase and peroxidase, then it will show that liver tissue has more catalase than potato tissue has peroxidase.

    Placed the rubber stopper in the test tube. 8. Observed for 30 seconds, collected data, and recorded it in the data table. 9. Cleaned and dried the test tube and placed it back in the test tube rack. 10. Massed 2g of finely chopped potato tissue. 11. Measured 1 mL of 3% H2O2 and added it to the test tube. 12. Placed potato on the side of the test tube so that it was not touching the H2O2. 13.

    • Word count: 1151
  5. Osmosis Lab. What is the effect of concentration of blackcurrant squash on osmosis in chipped potatoes?

    This is because there is a higher concentration of water in the chipped potatoes. In other words, the water moves outside the potato chip through the permeable membrane since there is a higher solute concentration outside the potato chips. Variables Independent Dependent Control Blackcurrant Squash Concentration (%) Change in mass of chipped potatoes (g) Total amount of solution Size of chipped potatoes Type of blackcurrant Squash Distilled water Control of Variables We controlled the variables by keeping the same amount of solution using a measuring cylinder, same size of chipped potatoes using the ruler and same size of borer, the same type of blackcurrant squash and distilled water throughout the experiment for consistency and accuracy of data.

    • Word count: 1185
  6. To stimulate the effect of acid rain on plant life, students to set up a lab experiment to compare the effect of varying levels of acidity on plant seed germination.

    Method for control Sunlight The lab's to be conducted after the curtains are drawn and the bags to be placed in a wooden drawer in a cupboard Purity of water The vessels to be cleaned properly before use so that the water oes not get contaminated and to test the pH of water before use so that water purity can be known. Amount of air in the zip bag Gently press the bags before zipping them and make sure that the max amount of air is lost.

    • Word count: 739
  7. Title: separation of pigments of photosynthesis using paper chromatography. Goal (main aim): Calculating the Rf of every single pigment, in order to distinguish it and identify its solubility.

    Volume & concentration of extraction The extraction sample will be taken using the same tweezers. Materials and procedure: Materials: 1- Chromatography Jar. 2- Plant. 3- Chromatography paper. 4- Solvent (organic). 5- Tweezers. 6- Pipette. 7- Mortar and Pestle. 8- Scissors. 9- Ruler. 10- Calculator. Procedure: * Preparation of the mixture: 1- Place a piece of the obtained plant leave into the pestle. 2- Add 5ml (approx.), of 90% isopropyl alcohol. * Preparation of the chromatogram: - Attain a chromatography paper. - Cut the paper, in order to have a triangular end. - Draw a line above the triangular end, with 1 cm, draw a point in the center of that line, the previous line is considered the start line.

    • Word count: 765
  8. Chromatography lab. Title: separation of pigments of photosynthesis using paper chromatography.

    Materials and procedure: Materials: 1- Chromatography Jar. 2- Plant. 3- Chromatography paper. 4- Solvent (organic). 5- Tweezers. 6- Pipette. 7- Mortar and Pestle. 8- Scissors. 9- Ruler. 10- Calculator. Procedure: * Preparation of the mixture: 1- Place a piece of the obtained plant leave into the pestle. 2- Add 5ml (approx.), of 90% isopropyl alcohol. * Preparation of the chromatogram: - Attain a chromatography paper. - Cut the paper, in order to have a triangular end. - Draw a line above the triangular end, with 1 cm, draw a point in the center of that line, the previous line is considered the start line.

    • Word count: 768
  9. Yeast lab. Question: how does the yeast concentration affect the rate of anaerobic respiration?? Measured by the concentration of released CO2.

    Controlled variables: Variable Why to control How to control Concentration of sucrose Because sucrose is the reactions substrate. It will be kept constant for all the trials. Temperature Higher temperature increases the rate of reaction The experiment will be initiated in room temperature away from air sources. Time 2 minutes for each trial Equipments and procedure: Equipments: - PASCO GLX with (CO2 sensor). - 200 ml, 3 % sucrose solution. - Variety of yeast solutions (g/ml) (2%,4%,6%,8% and 10%). - Cylinder. - Beaker (200 ml). - Plastic cover. Procedure: - Prepare at least 5 different concentrations of yeast (2%, 4%, 6%, 8% and 10%)

    • Word count: 844
  10. Experiment to find the water potential of the cytoplasm of potato cell (Solanum tuberosum linnaeus

    strips/g (0.02g) % Change of mass of the potato (Solanum tuberosum linnaeus) strips/% 0.1 1 0.05 9.43 2 0.04 7.27 3 0.04 6.90 4 0.04 7.02 5 0.04 7.02 0.2 1 0.02 3.57 2 0.03 5.17 3 0.03 5.26 4 0.02 3.17 5 0.01 1.54 0.3 1 -0.01 -1.79 2 0.00 0.00 3 0.00 0.00 4 -0.01 -1.39 5 -0.01 -1.00 0.4 1 0.02 -3.23 2 -0.02 -3.03 3 -0.01 -1.00 4 -0.01 -1.82 5 -0.02 -3.33 0.5 1 -0.05 -8.20 2 -0.04 -6.56 3 -0.04 -5.71 4 -0.03 -5.00 5 -0.04 -6.67 X 100% = % change in mass Table 1.2 % Change in mass of the potato (Solanum tuberosum linnaeus)

    • Word count: 1840
  11. Investigation Question: How does Body Mass Index affect heart rate with respect to exercise?

    After jumping jacks, immediately take subject's heart rate by counting pulse for exactly one minute 5) Record value in data table 6) Calculate % increase of heart rate using the formula provided below. Record value in data table 7) Repeat process for multiple trials (20 total) Formula for calculating percent increase of heart rate: (Heart rate after jumping jacks) - (resting heart rate) % Increase= __________________________________________________________________ X 100 (resting heart rate) Trial Body Mass Index Resting Heart Rate Heart Rate after jumping 1 20 66 127 2 19 60 129 3 22 72 118 4 26 66 93 5 21 84 126 6 29 84 140 7 24 78 120 8 22 96 98 9 22

    • Word count: 964
  12. Biology lab. Observing plant and animal cells using the light microscope

    They zone tightly to each other. Each cell has a dense transparent cover (cell wall, which supports the form of the cell) with the more subtle areas - pores, which can be discerned only under high magnification, using them cell gets the nutrients and take out unwanted substances. The composition of membranes of plant cells is of special substances - cellulose, which gives them durability. Inside is a colorless viscous substance - cytoplasm. In the cytoplasm there is a small, dense nucleus (containing the genetic information), where we can see the nucleoli. Some cells do not have any nucleus, it means that they are already dead.

    • Word count: 1075
  13. Laboratory work on a theme The dependence of the rate of photosynthesis on light intensity

    Aim Determine intensity of photosynthesis on allocation of ?2, depending on the light exposure. Variables Independent variable is the level of the illumination level, which I changed. Dependent variable is oxygen allocation, which depends on the illumination level. MATERIALS AND METHODS Materials Punch, cups, a solution of baking soda 0.5%, medical syringes with the cylinder 10 ml, glass tubes, the lamp of 100 W, a box, the leaves of plants (Chlorophytum). Chlorophytum Method 1)

    • Word count: 513
  14. Experiment. The dependence of the rate of photosynthesis on light intensity

    And if yes - how and to what extent? Research question How the light level may affect the release rate of oxygen during photosynthesis? Chemical studies of Lavoisier (1775, 1781) led to the conclusion that plants convert carbon dioxide into oxygen only in the presence of light. Light in photosynthesis plays a role not only catalyst, but also one of the reactants. A significant portion of the light energy used by plants during photosynthesis is stored as chemical potential energy in the products of photosynthesis.

    • Word count: 1096
  15. Osmosis Lab. Aim: To investigate the effects of different solute concentrations on osmosis, calculate water potential, and plant cell plasmolysis.

    Tomorrow, remove the potato cylinders from each solution and blot them with paper towel. Data Collection and Processing: For the experiment, data was taken from six different samples. We cut six of the same size potato cores and measured the mass. After we measured the temperature of each cup filled with water and the solutions. Five of the cups had a different amount of sucrose solution and the sixth cup was just filled with water and its constant. Placing the potato wedges in the different solutions, the osmosis began to work and I left the cups sealed for a day.

    • Word count: 1056
  16. Osmosis in potato experiment

    Processed Data: - The average final weight is obtained using the following rule: - The percentage change is obtained using the following rule: table (2): percentage change of potato cubes weight in different sucrose solutions: Percentage change in the mass of potato cubes Difference between final and initial weights in (g) (�0.1) g Average final weight (gram) (�0.05) g Sucrose solution Molarities (mol/L) 33.3 % 0.20 0.80 0.1 18.2 % 0.20 1.30 0.2 14.2 % 0.10 0.80 0.3 00.0 % 0.00 0.90 0.4 -14.1 % -0.24 1.46 0.5 -12.7 %

    • Word count: 614
  17. Lab Report: Coral Reef Ecosystem - LIT Technique. This experiment aims to assess the sessile benthic community of coral reefs in around the Pramuka Island (one of the islands amongst the Thousand Islands located in Indonesia)

    29.5 - 30.2 Sand, dead corals 30.2 - 30.8 Soft coral (Simularia sp) 30.8 - 31.2 CB 31.2 - 31.7 Sand, dead corals 31.7 - 32.8 CSM 32.8 - 33.25 Sand, dead corals 33.25 - 33.55 CB 33.55 - 34.2 Sand, dead corals 34.2 - 34.5 CB 34.5 - 38.4 Soft coral (Simularia sp) 38.4 - 38.7 Sand, dead corals 38.7 - 39 CE 39 - 40.3 CSM 40.3 - 41.6 Sand, dead corals 41.6 - 41.8 CM 41.8 - 42.8 CSM 42.8 - 43.7 CE 43.7 - 45 CB Processed Data: SITE 1 CORAL TYPE CALCULATION CSM CM Soft coral (simularia sp)

    • Word count: 1504
  18. Potato IA Lab. This experiment tested osmosis when dealing with different concentrations of salt on the outside of the membrane.

    If there is a higher concentration of salt on the outside of the membrane, then water will move across the membrane to the outside in order to reduce the concentration of salt. Variables: Independent variable: Salt concentration Dependent variable: Weight of potato cores Constants: Amount of distilled water Water temperature Size of potato cores Type of potatoes Type of salt Room temperature Apparatus: - 5 Red potatoes - 1500 mL distilled water - 15 Plastic cups - Table salt - 500 mL beaker - 100 mL graduated cylinder - 1 cm diameter corer - Stir plate - Permanent marker -

    • Word count: 1457
  19. 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
  20. Surface Area to Volume Ratio Simulation Experiment. The comparison between surface area : volume ratio and time taken for agar blocks to decolourise.

    Agar blocks Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Average 1 3723.00 3634.80 3624.00 2425.20 3655.20 3332.20 2 2889.00 2895.60 3460.80 2357.40 2459.00 2812.36 3 2160.60 2114.4 2487.00 2238.00 2126.80 2225.24 4 1769.40 1866.00 1920.00 1638.00 1683.00 1784.28 5 1444.20 1324.20 1518.00 1590.00 1419.40 1459.12 Table 1.3: The comparison between surface area : volume ratio and time taken for agar blocks to decolourise. Agar blocks Surface area : Volume ratio Averaged time taken for agar blocks to decolourise/s (�0.01s)

    • Word count: 1622
  21. Research Question: Does the duration of exercise have an increased effect on a persons heart rate?

    - The Type of exercise will be restricted to Jumping Jack. This is done because different exercises are more taxing than others, by at least each individual will be performing the same degree of activity. - Each person will record their base-level heart rate by exercising for 0 seconds. - The Temperature of the room will remain constant by allowing all individuals to exercise in the same room. Materials: -Clock Procedure: 1. Gather at least 10 students for exercise and 1 other student to watch time 2.

    • Word count: 1935
  22. How Does Exercises And Tea Affect Heart Rate And Blood Pressure rate as well.

    I will be testing these factors by two different kind of experiment firstly after drinking a cup of tea, and secondly after doing a hard exercise. FIRST EXPERIMENT (TEA): Materials: -Tea bag - boiling water at 100 Celsius - 275 ml glass cup - Stethoscope. -Sphygmomanometer �5 mmHg -Stopwatch �0.01 sec. General Information: Blood pressure and Pulse rate must be measured with a beat Per Minute (BPM) and the pulse rate with Millimetre of Mercury Variables: a) Independent: amount of tea. b) Dependent: -The results of different values of blood pressure and pulse rates (-Pulse Rate �1 BPM) I reached.

    • Word count: 1628
  23. In this extended essay I am looking at the effect of different kind of music on same species of plant. I will take Chickpeas (gram seeds) to perform a lab showing the effect of music on them. I will choose four different situations to see the effect of mu

    First I will take twenty seeds of chickpeas and divide it into four groups. Then I will germinate them placing them in cotton, soaked in water. At the same time I will write the name of the music on each group and will play the same kind of music written on the plate. I will play music on each group of plant for three hours a day. I will keep the plants that come in no sound group in an isolated room where all the conditions are similar to others but sound cannot be heard from there.

    • Word count: 5724
  24. Catalase lab. This intent of this lab is to investigate how the factors of different pH levels and how they affect catalyze activity on the decomposition of hydrogen peroxide.

    Planning (a) Research Question- What affect does the change in pH level of hydrogen peroxide (??2??2) have on the amount of height of the bubbles (??2 liberated) when hydrogen peroxide (??2??2) reacts with a catalase enzyme after one minute? Hypothesis- When the pH level of the hydrogen peroxide (??2??2) is too high or too low from neutral pH (pH of 7), the oxygen (??2) liberated from the catalase activity will be decrease. Variables- Variables Units Range Independent Variable pH level of hydrogen peroxide (H2O2)??2??2 solution Hg In pH pH levels of 2, 4, 6, 8, 10 Dependent Variable Height of the foam (oxygen (??2)

    • Word count: 1867
  25. 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

Marked by a teacher

This document has been marked by one of our great teachers. You can read the full teachers notes when you download the document.

Peer reviewed

This document has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the document page.

Peer reviewed

This document has been reviewed by one of our specialist student document reviewing squad. Read the full review under the document preview on this page.