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International Baccalaureate: Biology

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  1. Genetic Technology Biology Lab

    Extension 1. Lane A (BanHI): 16841bp, 7233bp, 6770 or 6527bp, 5626 or 5505bp Lane B (EcoRI): 21226bp, 7421bp, 5804 or 5643bp, 4878bp, 3530bp Lane C (HindIII): 23130bp, 9416bp, 6557bp, 4361bp, 2322bp, 2027bp, 564bp, 125bp Lane D (Control): 48514bp 2. 3. I saw only five fragments with EcoRI when there should be 6, and four fragments with BamHI when there should be 6 because some of the fragments were masked by other fragments since the masses of those fragments were fairly similar, thus it appears that there is only one fragment in a certain band, but there is actually 2.

    • Word count: 1027
  2. Human Pedigrees Biology Lab

    However, research has shown that heterozygous individuals. However, research has shown that heterozygous individuals have enhanced resistance to malaria. What effect might this factor have had on the frequency of the sickle-ell gene in populations of North American blacks? Since heterozygous individuals have a enhanced resistance to malaria, then that means that the homozygous dominant and recessive individuals are more susceptive to malaria, thus they are more likely to die. Meaning that, the heterozygous population would be greater than that of the homozygous population. Thus there is high probability that children come from heterozygous parents, and if heterozygous individuals have children, then the probability that the child would carry the gene is 75%, but only a 25% chance that they will have the sickle-cell disorder.

    • Word count: 933
  3. Biology Cell Lab

    Data Collection and Processing Raw Data Table Length (�m �50�m) Width (�m � 50�m) 26.7 22.9 150 33.3 56.3 34.6 84 42 84 52.5 100 50 100 50 67.4 31.8 55 22.5 70 40.7 70 44.5 70 21 Mean= 77.7 Mean= 37.2 Class values of the sizes of Elodea Class values of the sizes of Human Cheek Cell Length (�m�50�m) Width (�m � 50�m) 46.7 30 32.1 40 34.3 30 53 53 36.2 38.2 32 31.6 70 26 51 38.2 46.7 30.5 52.5 28 26.3 Mean= 45.5 Mean= 33.8 My values of the sizes of Elodea Length (�m�50)

    • Word count: 1098
  4. Influence of pH on the activity of potato catalase

    PH dependence on enzyme's activity is one of the most essential factors regulating the speed of the reaction. Small changes in pH does not deactivate the enzyme, but they lower the speed of the reaction, because they influence ionisation degree of enzyme and substrate, changing the conditions of creating enzyme-substrate complex. Strongly acidic or strongly basic enviroment usually denaturates, destroying irreversible bonds stabilizating the enzyme molecule. Variables: * Dependent = time that water needs to pass 5 cm in manometer tube, time * Independent= pH of the buffers * Controlled= size and number of potato discs, volume of buffers, distance of 5 cm, pressure, temperature, level of buffer in manometer tube Method: 1) Prepare Create buffers (Table 1)

    • Word count: 1889
  5. Experimental Design Notes

    -> data table or graph o Things to consider: How are you going to arrange your data? o Data presentation: Table: allows one to organize data in a way that shows relationships o Graph: Visual image is easier to see Statistical Analysis * Why use it? o Science requires observations and collections of measurable data o Ex. Investigation question is what is the height of bean plants growing in the shade? o How many bean plants to study? * Can't study thousands of bean plants b/c time, money and land, labor o Need to take a sample of bean plants

    • Word count: 1893
  6. seed lab

    It is anticipated that the seeds that are presoaked for 36 hours will be the most responsive. Since 36 hours is the median for 3 days, the seeds will be exposed to favorable conditions. However, it will not absorb too much water in 36 hours to become exceedingly sensitive and fail to germinate. The independent variable is the length of time of the presoaking. The seeds will be presoaked for varied amounts of time, specifically 12 hours apart; they will be underwater for 0 hours, 12 hours, 36 hours, 48 hours, 60 hours, and 72 hours.

    • Word count: 952
  7. Osmosis in potato

    Explanation: If we put the piece of potato in distilled water molecules pass from high concentration (the water itself) to low concentration (in the potato piece). The water moves towards higher concentrations of solution (from high concentration of water to low concentration of water). That means that if the water outside the cell is saltier (has lower concentration of water) than the water inside, water will move from the inside of the cells to the outside. Therefore, the piece in higher concentrations of water will have a larger mass than the piece in salt concentrations.

    • Word count: 1027
  8. gmf. positive and negative drawbacks.

    Scientists have been working already for centuries on how to produce stronger and better producing crops. Hybrids are undoubtly a common element in the world of living plants either by pure coincidence of nature or by the hard work of scientists who have been pursuing different alternatives for seeds, plants and trees. For example, 99% of the fruit we eat today is produced by trees that have some form of hybrid contexture which makes them much more effective in producing their respecting produce fruits and etc. 1 Why therefore, do we see such lively debates about GMF these days?

    • Word count: 1041
  9. Determining the relationship between sample size and margin of error

    Table 1: Estimate population size and percentage error Trial Round # Number Recaptured Number of Marked Recaptured Estimated Population Size Actual Population Size Percentage Error (%) 1 1 10 1 200.0 150 33.3 2 15 2 150.0 150 0 3 20 3 133.3 150 11.1 4 25 3 166.7 150 10.9 5 30 4 150.0 150 0 2 1 10 2 100.0 150 33.3 2 15 3 100.0 150 33.3 3 20 2 200.0 150 33.3 4 25 5 100.0 150 33.3 5 30 5 120.0 150 25.0 3 1 10 1 200.0 150 33.3 2 15 3 100.0 150

    • Word count: 1264
  10. affect of age on reaction time

    will socre the worse for the reasons above. Variables: 1. Independent: The ages of the people I test. I will have to vary the ages of the people I test as my aim is to measure the effect of age on reaction time. 2. Dependent: The reaction time. I will measure the reaction time by seeing the point in which the person caught the 45 cm ruler in. Therefore indicating the reaction time by seeing if it increases (the person holds the ruler at a certain point, the reaction time increases when the point the person caught the ruler on decreases)

    • Word count: 1211
  11. Climate Crisis Lab Report

    to use the CO2 levels from the month of June for the first ten years from 1959 to 1968 and from 1997 to 2006 because I wanted a wide range of data selection so I chose the ten most recent years and the first ten years of data collected I Mauna Loa. I did not include the CO2 level from June 1958 because no data was collected in that month. I decided to choose the month of June because of seasonal variation and in order to keep the data constant.

    • Word count: 1120
  12. An investigation into the effect on Osmosis by varying the concentration of water

    Independent Variables- The independent variable would be the concentration of the solution because we are checking to see if the change in concentration effects Osmosis. Controlled Variables- The controlled variables would be the volume of solution, the shape (surface are) of the potato, type of potato. We want to control the surface area of the potato and the type of potato we are using because changing the surface area of a potato can effect the results. Method: 1. Cut the potato into 6 cylinder slices using a cork borer, and calculate the initial mass of the potato pieces using an electrical balance.

    • Word count: 938
  13. Investigating Surface Area to Volume Ratio concerning the rate of Diffusion

    Constant Variable (CV): time, stopwatch, ruler, same bottle of . Method: - Firstly, cut the agar gel using a knife. Then calculate the surface area and volume of each agar cube. Try to make sure each agar cube is as accurate as possible. - Take the (2x2x2) agar cube and place it into a beaker. - After that pour into the beaker and make sure that the agar cube is covered with solution. - All three cubes of the same volume should be covered with. Then start the stopwatch. - Leave the agar cubes in the solution for 2 minutes.

    • Word count: 833
  14. Investigating Variation in Leaf Size

    - After that place the leaves on a piece of squared paper (4mm�) and draw around them with a pencil. Next count all the individual squares and record the numbers in a chart. - Take the number of the squares for each leaf and multiply that number by 4. (For example: 132 is the number of counted squares and multiplied by 4 it equals 528). - After calculating the area of each leaf, record the results in a table. - By adding the numbers together and then dividing that number by two, you will be able to calculate the mean of each leaf type.

    • Word count: 563
  15. Credit River Abiotic Feature Study

    Another abiotic factor that will influence the temperature of the Credit River is the average depth. I hypothesize that quadrants with a greater depth will have a lower average temperature than those with a more shallow depth. Lastly, I predict that quadrants with higher velocities will equate to an increased temperature in the Credit River. Variables There are both independent and controlled variables in this lab. The controlled variables in the experiment encompasses the method, amount of intersects, the height of transect/measurements, size of quadrant, transects, location of site, time of year and day and the place of data collection.

    • Word count: 928
  16. Cellular Respiration. Explain aerobic respiration including the link reaction, the Krebs cycle, NADH + H+, the electron transport chain and the role of oxygen.

    The link reaction occurs between glycolysis and the Krebs cycle. The two pyruvates that are created in glycolysis eventually turn into acetyl CoA. This process begins in the cytoplasm and membrane proteins move the pyruvates into the mitochondria and eventually into the mitochondrial matrix. In the matrix enzymes break down pyruvate, taking off H and CO2 (decarboxylated)(Campbell 167). The H+ is then accepted by NAD+ which turns it into NADH+H+ and the CO2 is a waste product (Campbell 167). The remaining product is an acetyl group which is accepted by CoA and forms acetyl CoA.

    • Word count: 911
  17. DNA Structure questions. Outline DNA nucleotide structure in terms of sugar (deoxyribose), base and phosphate.

    Uracil is only present in RNA and thymine is only present in DNA (Eggling 1). The NH groups on the carbon rings will be used to create a bond between the bases and the sugars. The phosphate group can be either an ion or an acid (Eggling 1). 3.3.2 State the names of four bases in DNA. cytosine (C) thymine (T) uracil (U)

    • Word count: 487
  18. Biology Lab Report-Osmosis

    than the potato cells. This creates a concentration gradient. If the concentration of the solution is lower than the concentration within the potato cell, then water from the solution will move into the cell, through its semi-permeable membrane by osmosis. Thus, each cell of the potato chip will increase in size and mass as water enters it. These cells would look like the cell in Fig.1. A solution which brings about such changes in known as a hypo-osmotic solution. Each cell becomes turgid and the chip as a whole shows the net result of these changes.

    • Word count: 1848

    B.)DEPENDENT VARIABLE: THE LENGTH AND Breadth are dependent variables, as they both depend on the area of the plant,whether exposed to bright sunlight or not. C.)CONTROLLED VARIABLE: We controlled that both the branch had come from the same type of plant(same species), while measuring plants from shaded areas for example, we controlled that all leaves are taken from the same tree and same branch,another factor we tried to control would be that both plants (one from shaded area and one exposed to bright sunlight)are taken from the same size of tree(not one young and one old tree.) METHOD: (CONTROLING VARIABLE)

    • Word count: 815
  20. Vitamin C Lab

    This experiment will study temperature, an abiotic factor, on how it affects Vitamin C by calculating its concentration in lemon juice by titrating lemon juice against dichlorophenolindolephonol (DCPIP) and see how much DCPIP is needed to decolourise a controlled amount of lemon juice (2cm3). Aim Design a quantifiable investigation to look at the effect of at least one abiotic factor - in this case temperature - on Vitamin C. Hypothesis I think that as the temperature increases, the Vitamin C concentration within the lemon juice will decrease.

    • Word count: 2402

    Therefore, the percentage coverage of lichen on the trees is going to be higher in an area with sunlight compared to a shaded area. Also the direction of the tree (North, East, West or South) affects in the growth of lichen. Apparatus: * Meter rule (x1) * Compass (to find the north direction) (x1) * Mini transparent quadrat with marked squares (x1) * Pencil / pen * Paper * Calculator Method for controlling variables: * The investigation should take place in two different areas, one which has trees growing in a sunny area and another one which has trees growing in shaded area and it should not be carried out elsewhere from these two selected area.

    • Word count: 2608

    ~ 0-600 lux is used for low levels of illumination ~ 0-6000 lux is generally appropriate for indoor light levels ~ 0-150,000 lux is mainly used for measurements in sunlight. (http://teachers.oregon.k12.wi.us/fishwild/mbl.htm) Method for controlling variables: * The investigation should take place only in a certain part of the area and it should not be carried out elsewhere from that selected area. * The time of the day should remain the same whenever the investigation takes place so as to keep the amount of sunlight constant or similar.

    • Word count: 1254

    * Measure out 0.15g of yeast on the same electronic weighing scale for all tests. * Use a stopwatch instead of a normal wristwatch or a clock so as to have a smaller uncertainty. * Make sure that the temperature of Hydrogen Peroxide is same in all concentrations through out the experiment. * Use the same size of test tubes through out the experiment so that the time does not vary a lot for the reaction to reach the top of the test tube.

    • Word count: 1694
  24. investigating the action of pepsin on egg white

    After some, time the circular muscle between the stomach and the small intestine called pyloric sphincter opens briefly and a small amount of acid chyme is allowed into the duodenum. The wall of the stomach is made of protein, and pepsin works on proteins in order to avoid self-digestion of the stomach wall, pepsin is released as an inactive form (Pepsinosion), which is activated by the acidic environment that's why stomach secretes HCL In this experiment, we are investigating the action of the enzyme pepsin on the egg white (the protein).

    • Word count: 635
  25. Investigating the relationship between diffusion and Size of the Cell

    Variables: Independent- size of the agar cube Dependent - Time taken for diffusion Controlled:- - Room Temperature - Concentration of the Acid - The amount of acid Apparatus: 1) Jelly ( Agar in big Petri dish with phenolphthalein in it) 2) Two small Petri-dishes 3) Scalpel 4) Plastic ruler 15cm 5) Stop watch 6) Four Beakers 7) 0.1 m of hydrochloric acid Method: 1) Obtain the Agar that is in the Petri dish. 2) Using the plastic ruler and the scalpel cut out two agar cubes of 1cm by 1cm.

    • Word count: 790

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