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International Baccalaureate: Biology

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  1. Measuring the diversity of plant species in an area.

    5. Use a random number generator to obtain 3 numbers each for each of the given species. You should have 3 plants from each species equating to 15 selected plants on the map. 6. For those chosen, find the area for all 15. Take the average of the three of each species to find the average area that will be used. This will later be used to obtain the raw sum of trees for the quadrants later. 7. Using a random number generator, obtain 2 random numbers, one being the range from 1 to the length of the width of the map and the second being from 1 to then length of the map.

    • Word count: 1503
  2. The effect of NaCl solutions on the mass of potatoes

    This experiment can be used on other vegetables as well, in order to increase the production of the fields. Materials used: * 1L beaker * 6 40mL test tubes * 1 100mL measuring cylinder * Test tube rack * Salt * Electronic scale * Two-Three potatoes * Scalpel * Ruler * Distilled water * Oil pen * Paper towels * Aluminum cover Procedure: 1. Cut six potato pieces using the scalpel and ruler a. Each piece should be rectangular b.

    • Word count: 734
  3. Experiment - The amount of cell division in the Allium cepa root tip cell

    It is important to know how fast plants can grow, in order to determine how long does it take them to develop, and as well this experiment could be used on corn roots, to know when people can plant them and as well harvest them. Procedure: 1. Set up the microscope with the sample a. Pick a thin layer of the onion root tip b. Put it on the slide i. Make sure the sample does not bend/fold c. Put one drop of water d.

    • Word count: 662
  4. The variation of rate of enzymatic activity of Bos primigenius liver with respect to surface area

    area will be comparable, and from there the data as well Amount of hydrogen peroxide poured into the container 10 mL Being one of the reactors, the amount of hydrogen peroxide is a potential factor for the enzymatic activity rate, so it will be controlled Amount of time of recording data 1 minute In order to receive adequate data for processing, every trial should be run at the same conditions, including time, because pressure might keep on going to build up in the nalgene bottle Procedure: 1.

    • Word count: 795
  5. Osmosis Experiment. This experiment is to consider how salinity influences osmosis in potato cells.

    But my prediction is that for the control experiment, the mass of the potato will increase as the pure water has a weaker concentration than the potatoes and thus the water molecules will enter the cell making it heavier. Background Information Osmosis As explained earlier, osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. (1997 - 2000, Purchon)A semi-permeable membrane refers to a very thin layer of material, also known as a membrane, which allows some substances through its membrane but doesn't allow other substances.

    • Word count: 4287
  6. The effect of the tempereature on yeast metabolism.

    Enzymes are catalysts that speed up reactions; they are made from protein and are specific as to which substrate they work on. For example a zymase-complex enzyme will only bind with a glucose molecule to produce the ferments carbon dioxide and alcohol. Yeast has to make energy, stored as ATP to carry out all cellular functions. To do this they respire. They can respire both aerobically (when there is plenty of oxygen and the cells reproduce rapidly), or, where oxygen is short, they can respire anaerobically; in this process they are called partial anaerobes.

    • Word count: 1767
  7. Osmosis. By this investigation, I tried to find out the changes in potato cylinders masses dependently on sucrose solution

    * Potato cylinders in 1.0 M, 0.8 M, 0.6 M, 0.4 M solutions were floating while in 0.2M and 0.0 M solutions it was fully on the bottom. On the other hand in 1.0M solution it was on the top, while in 0.8 M solution a bit lower, 0.6 M more lower etc. That's because of density's differences. * Levels of solutions looked different (it looked that volumes are not the same) (lowest in 0.6M and 0.2M solutions, highest in 0.4 M, 1.0 M solutions.).

    • Word count: 1490
  8. Cell Organelles summary table

    SMOOTH It's a system with of membranes within the cytoplasm, which enclose a space known as the lumen. It has no ribosomes on its surface. Detoxification of drugs and lipid synthesis (including phospholipids and steroids) etc. Both Golgi Apparatus It's a series of flattened membranous sacs (cisternae) looking like a stack of Pita bread. It's dynamic structure as vesicles are constantly being added from the ER, and new vesicles are budding off. Cells may have a few to several hundred of these structures. It receives vesicles full of protein from the ER, then may be modified and packaged into vesicles which may transport them to other organelles or to the plasma membrane for secretion.

    • Word count: 541
  9. This practical aims to demonstrate the effect of osmosis on potatoes in sucrose solutions of varying concentrations.

    Figure 1: Initial and Final Mass of Potato tubes Sucrose to Water Initial potato tube mass(g) Final potato tube mass (g) Percentage change in mass 0mL:20mL 2.88 2.72 -5.56% 5mL:15mL 3.1 3.03 -2.26% 10mL:10mL 3.16 3.15 -0.32% 15mL:5mL 3.17 3.21 1.26% 20mL:0mL 2.8 2.93 4.64% Figure 2: Graph depicting the percentage change in mass of the potato tubes in increasing concentration of a sucrose solution with the red line representing the line of best fit. Conclusion: The difference between the potato in the complete sucrose solution compared to potato in the distilled water is extremely high.

    • Word count: 719
  10. Breast cancer. Successfully treating breast cancer means the removal of the cancer or controlling it for a period of time, but because breast cancer is made up of many different sorts of cancer cells, getting rid of all those cells can require all differe

    Successfully treating breast cancer means the removal of the cancer or controlling it for a period of time, but because breast cancer is made up of many different sorts of cancer cells, getting rid of all those cells can require all different types of cancer treatments such as: surgery, radiation therapy, chemotherapy and hormonal therapy. Even though all these treatments have proven to cure breast cancer for millions of people, one treatment may not work for a specific person. At stage 0, There are no signs of cancer cells breaking out of the area of the breast in which they had started or of getting through to or invading normal tissue.

    • Word count: 1648
  11. Research Notes - Genetic Engineering & Biotechnology

    > Extraction of that gene is usually taken out by the molecular level with computer. > Gene is then placed in to Gamete B's nucleus and artificially fertilized with another gamete cell to form a zygote. > New organism is created with modified DNA. > E. coli is the most widely studied plasmid in the world. Therefore, is most commonly used. > Uses: > It has many strains that are fatal to humans. The E. coli gene which produced vitamin k was extracted then added to cows in Africa so the people would receive appropriate amounts of the vitamin.

    • Word count: 1264
  12. Heart Recoil IA. Aim To compare the recoil and subsequent elastic limit of a mammalian aorta and vena cava.

    Vena cava ((length with mass-length without mass)/ length without mass) x100 ((3.6-3.4)/3.4) x 100 5.8% Aorta ((3.8-3.3)/3.3) x100 15.2% Observations From observations, the walls of the aorta are clearly thicker and feel tougher than the vena cava. The aorta is also light in colour (light flesh pink) whilst the vena cava is a darker plum red. Analysis The first two tables of results above shows the elastic recoil of the vena cava and the aorta. It demonstrates as the length of the vena cava/aorta when the mass is put on and when the mass is removed to see if it has stretched. The mass increases down the table from no mass (0)

    • Word count: 1491
  13. Enzyme Investigation. How does the concentration of hydrogen peroxide affect the amount of oxygen produced by the enzyme catalase?

    This means enzyme activity increases and the rate of reaction also increases. Independent and dependent variables Variable measured Method of measuring variable Independent variable Hydrogen peroxide concentration (%) The 5 values I will use for the concentration of substrate hydrogen peroxide would be 20%, 40%, 60%, 80% and 100%. These percentages will be calculated from the hydrogen peroxide to water concentration radio where water is used to dilute the hydrogen peroxide. The concentration percentage/ hydrogen peroxide to water ratio will be as follows: - 4ml: 16ml = 20% - 8ml: 12ml = 40% - 12ml: 8ml = 60% - 16ml: 4ml = 80% - 20ml: 0ml= 100% Dependent variable The volume of oxygen produced (cm3)

    • Word count: 873
  14. Research Question To what extent does watching different genres of movies affect our sympathetic and parasympathetic nervous systems, causing changes in heart rate?

    These neurons release the neurohormone acetylcholine, which inhibits heart rate. The slowing of heart rate is called bradycardia. Another major role playing hormone is adrenaline which causes an immediate hike in the heart rate. Hypothesis Different stimulus causes different changes in heart rate because of varied responses from the sympathetic and parasympathetic nervous systems. Watching horror and action movies should cause a greater increase in the heart rate, whereas, comedy and romance are more probable to cause a slight hike. On the other hand, watching a musical is expected to make the heart rate stable and almost near normal as the softness of the music used this case is supposed to make any living creature calm.

    • Word count: 804
  15. Chromatography of photosynthetic pigments. Aim: To determine the different photosynthetic pigments found in spinach and find their relative front values using paper chromatography.

    b (cm) Experimental Rf Standard Rf Carotene 5.7 6.2 0.91 0.98 Phaeophytin 3 6.2 0.48 0.53 Xanthophyll 2.4 6.2 0.38 0.3 Chlorophyll a 1.9 6.2 0.3 0.42 Chlorophyll b 1.2 6.2 0.19 0.34 Comparison of the Experimental and Standard Relative Fronts of Photosynthetic Pigments Evaluation Carotene travelled the furthest away from the loading line (5.7cm ) while chlorophyll a demonstrated the shortest distance travelled (1.2).

    • Word count: 552
  16. Plant Cromatography Lab Report. How does the use of different colored leaves affect the amount of colour traveled within paper chromatography?

    Temperature Throughout the experiment, the four samples had a room temperature of 23 � 0.05. This is because the use of different temperatures throughout the experiment can have an effect on the colour observed within paper chromatography. Time All four chromatographs were placed within the test tubes at relatively similar times to ensure that there is an insignificant time difference between the four samples. Thus, this could reduce the percentage error within the experiment. I. Methods Materials & Apparatus * 4 Test tubes * Filter papers * Glass rod * Two disposable gloves * Graduated cylinder (50 ml)

    • Word count: 1037
  17. 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
  18. Biology Lab Report - Effects of Mouthwash on Oral Bacteria

    Mouthwash may also be used to help remove mucus and food particles deeper down in the throat. This experiment therefore aims to find out the effectiveness of mouthwash against oral bacteria. Mouthwash 'A' is 'Oral B - Natural Mint', an anti cavity mouthwash designed to prevent the occurrence of cavities in teeth. Mouthwash 'B' is 'Scope-Mint', is anti bacterial in nature. Mouthwash 'C' is 'Listerine-Cool Mint', is antiseptic. The last variable is distilled water, the control in the experiment. 1.

    • Word count: 1085
  19. Protein Digestion Design Lab. To detect the amount of protein molecules or short polypeptide chains in the cooked egg white for this experiment, the biuret reagent will be used.

    Every enzyme functions most effectively at a specific pH. For example, pepsin, the protein-digesting enzyme secreted by the cells of the stomach lining, functions optimally at a pH of 2, depending on the substance being digested. On the other hand, trypsin, a protein-splitting enzyme secreted by the pancreas, functions optimally in an alkaline medium at a pH of 8.5, depending on the substance being digested. Most intracellular enzymes have pH optima near neutrality and do not operate successfully in an acid or alkaline medium.

    • Word count: 1521
  20. Lung Volume Measurement Biology Lab. My hypothesis is that the breathing rate and tidal volume increases after exercise.

    Put your mouthpiece into the hose opening of the spirometer. 4. Inhale normally. Put the mouthpiece in your mouth and exhale normally. Measure the volume and record as your tidal volume. Repeat this step 2 more times. Calculate the average tidal volume and record. 5. Inhale as deeply as possible, put the mouthpiece in your mouth and exhale as much air as possible. Measure the volume and record as your vital capacity. Repeat this step 2 more times. Calculate your average vital capacity and record.

    • Word count: 985
  21. The effect of varying temperature on the permeability of plasma membrane on beetroot.

    nucleus, mitochondrion.1 Beetroot has a betalain pigment, which makes it appear dark red or purple in colour. By putting beetroot cores into water with varying temperature, it affects the cell membrane. The cell membrane is made up of two layers of molecules, so it's called "bilayer" ("bi" means two). The molecules in this bilayer are called phospholipids. Each of these phospholipids has a head and a double tail. The head is hydrophilic.

    • Word count: 528
  22. Research Question: Which method of DNA extraction (using a centrifuge or not) will yield the most DNA, and which fruit (banana, papaya, or strawberry) contains the most DNA?

    extracted from each source Controlled variables: initial amount of fruit used in each trial, identical method of DNA extraction (aside from the use of centrifuge) Materials and Methods Equipment * 90% isopropyl alcohol * 100mL graduated cylinder * dishwashing soap solution * test tube rack * Test tubes for centrifuge * Centrifuge * 500mL beakers * Salt (NaCl) * pipets * coffee filters * fruits (papaya, strawberry, banana) * Plastic zip-lock bags * Electronic balance beam * Glass stirring rods Procedure 1.

    • Word count: 1065
  23. Biology- Extended essay. For this research, I investigated the effects of DDT and an Azo-Dye on the opercular movement of Mrigal (Cirrhinus cirrhosus) a fresh water fish.

    From the results that I recorded, and observed I can say that DDT, the Azo-Dye and the mixture of these two toxins reduce the opercular movement of Mrigal. The graphs show a clear trend of decline in the opercular movement. The results of the three investigations helped me conclude that DDT and the Azo-Dye both have a similar affect on the opercular movement of the fish and that the mixture of these two toxins is collectively more dangerous. These toxins affect the fishes by reducing their opercular movement with an increase in concentration.

    • Word count: 6440
  24. Experiment - Influencing the Rate of Photosynthesis with Light Intensity and Carbon Dioxide Concentration

    However, gradually temperature will decrease the rate of photosynthesis as the enzymes denature. Purpose and Hypothesis Purpose: To determine the affect of light intensity and carbon dioxide concentration on the rate of photosynthesis. Hypothesis: If the light intensity and amount of CO2 increases, then more oxygen bubbles will be produce because the rate of photosynthesis has increased. The rate of photosynthesis will increase because increased light intensity increase the energy chlorophyll absorbs, which then produces more productions including oxygen. The carbon dioxide concentration increase allows the enzymes to be saturated which also increases the rate of photosynthesis.

    • Word count: 1744
  25. Questions on RNA and DNA, bacteria and immunity.

    Step 1 * The DNA double helix is unwound and separated into strands by breaking the hydrogen bonds. * Helicase is the main enzyme involved. Step 2 * The single strand act as templates for new strands * Free nucleotides are present in large numbers around the replication fork * The bases of thee nucleotides form hydrogen bonds with the bases on the parent strand * The nucleotides are linked up to form the new strand * DNA polymerase is the main enzyme involved Step 3 * The daughter DNA molecules each rewind into a double helix (c)

    • Word count: 662

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