• 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. 19
  3. 20
  4. 21
  5. 22
  6. 23
  1. Explain how water moves from the soil into the plant

    Now, the water is transferred to the xylem. The xylem is located in a central column of the root. As there is a water concentration gradient within the root, the water can after having entered the root via the root hairs continue across the cortex to the endodermis of the xylem by osmosis. In the endoderm cells, the water is forced to move through the cytoplasm. Root pressure occurs, the gradient of water concentration that is present across the cortex.

    • Word count: 484
  2. Genetically Modified Food

    Before applying genetic technique in food, farmers also practiced the artificial selection on agriculture and cattle. They always choose the better quality crop which imply having better gene to produce next generation so that the overall quality of food was improving. Using advanced biotechnology can do it in a faster and accurate way. Scientists know that the genes of an organism determine its feature and appearance. So the scientists use a special technique to alter the genetic material inside. It is like the ?copy and paste? method on the computer.

    • Word count: 1326
  3. Are Viruses Alive?

    The viruses are then passed out in the bloodstream, the airways, or by other routes. Structure of a Virus: ?A virus particle, also known as a virion, is essentially a nucleic acid (DNA or RNA) enclosed in a protein shell or coat. Viruses are extremely small, approximately 15 - 25 nanometres in diameter.? 1. Certain viruses contain ribonucleic acid (RNA), while other viruses have deoxyribonucleic acid (DNA). Flu Virus (H1N1 Virus) 1. The nucleic acid portion of the viruses is known as the genome. The nucleic acid can be single-stranded or double-stranded; it could also be linear or a closed loop; it may be continuous or occur in segments.

    • Word count: 663
  4. Ecological studies of rice (Oryzae Sativa) populations

    and are the standard deviation values for the first and second populations respectively. 3. and are the number of replicates for the first and second populations respectively. T-test value for populations A and B: For a degree of freedom of 58, (, the critical value in the probability table is 2.001 at a significance level of 95%. Since the calculated t value is higher than that of the critical value, there is a significant difference in the lengths of the rice grains.

    • Word count: 1518
  5. Monohybrid Crosses in Maize Cobs

    Genotypes = Cc Cc Parental Phenotypes = Coloured Fruits x Coloured Fruits Phenotypic Ratio =1 Colourless Fruit: 3 Coloured Fruits Genotypic Ratio = 1 Homozygous Dominant: 2 Heterozygous: 1 Homozygous Recessive Comparison between Theoretical Result and Expected Result According to my results, the ratio of colorless kernels to colored kernels is 1:2.5 or in other words for every 2 colourless kernels, there are 5 coloured kernels.

    • Word count: 402
  6. Ecosystem Field Walk

    Lady bugs and honey bees use pollen as a source of food. 6. The gestation period for a lady bug is 3 or 4 days and hatch a few to several dozen lady bugs. After a few days lady bugs are able to reproduce once again. Only the queen bee reproduces for the honey bees, and can lay up to two thousand eggs a day. The queen bee has one mating flight where she stores enough eggs to lay for the rest of her life.

    • Word count: 876
  7. IB ESS Practical DCP - Study of Compost and DiAmmonium Phosphate

    The next day we measure the weight of the beaker and then we microwave it. Then again we measure the weight of the beaker to measure how much water was lost during the microwave. Repeat it 6 times to find a good degree of accuracy. 2 min 110 degrees under micro convection Variables: 1. Input Variable : DAP, Compost 2. Controlled Variable: Weight of Compost, Weight of DAP, Type of soil, 3. Output variable: Water Raw Data: Weight Of soil+compost+water (BEFORE MICROWAVE) Weight of soil+compost+water (After Microwave) Difference Soil sample A 180.10 176.80 3.3 Soil Sample B 182.24 181.12 1.12 Soil Sample C 177.15 176.15 1 Soil sample D 187.15 186.16 -1.01 Soil Sample E 200.53 200.27 0.26 Soil Sample F 184.53 184.05 0.48 Mean: 0.858333 Standard Deviation: 1.293708 Weight Of soil+DAP (BEFORE MICROWAVE)

    • Word count: 630
  8. Identification of Carbohydrates ,Lipids,and Proteins lab

    Living things need lipids for long term energy storage, insulation, and to form structural components of cells. Lipids are formed when a glycerol combines with three fatty acids. Lipids can be detected through the means of rubbing substances on paper. If lipids are present, the paper will turn translucence. Lipids can also be identified through the means of an emulsion test. When a sample is soaked in ethanol, the lipids dissolve. The solution is then poured into water. Since lipids don?t dissolve in water, when the ethanol is diluted, it falls out of solution.

    • Word count: 1512
  9. Investigation Of Factors That Affect Carbon Dioxide Production In Yeast

    Therefore, a two-tailed t-test was conducted by using the formula TTEST in Excel . Since the p-value is equal to 0.003, it indicates that there is a lower than 0.05 probability (5% chance) that the two sets of data are from the same population. As a result, it can be concluded that the two sets of data are significantly different. Figure 2: Figure 3: Conclusions: The immediate conclusions that can be drawn from the results in accordance to the collective data are that the optimal temperature for yeast to metabolize sugars is in the range between 40.00C and 50.00C (Figure 2), fructose is the type of sugar that is most readily metabolized by yeast (Fig.

    • Word count: 1791
  10. Experiment Plan. What effect does 2 minute of each leg muscle stretch (hamstring, calf stretch, thigh stretch) before exercise have on the rate of increase of heart rate during the exercise?

    By definition, stretching is movement of a joint or muscle to full extension by lengthening the tissues. People stretch to increase their flexibility and range of motion; they stretch before intense work out sessions and to prevent injuries and rehabilitation. Stretching leg muscles before exercise leads to an increase in blood flow. This leads to a higher requirement of oxygen and this causes a higher than normal heart rate before the actual exercise. Since the blood is already flowing at a quicker rate the heart rate should increase at a slower rate.

    • Word count: 886
  11. Testing the effect of substrate concentration on enzymes

    This type of reaction where a molecule is broken down into smaller pieces is called an anabolic reaction. RESEARCH QUESTION What will be the effect of increasing the concentration of the hydrogen peroxide on the rate of activity of the enzyme liver catalase reacting with it in a given period of time? HYPOTHESIS If all other factors such as temperature and pH are kept constant, increasing the substrate concentration will increase the activity of the enzyme to a point where it will reaches a maximum and remains constant because at its maximum rate the active sites of all the enzyme molecules in solution are occupied by a substrate molecule.

    • Word count: 2787
  12. Sleep is a normal part of human life. Investigate the neurobiological basis of normal healthy sleep and sleep-deprivation.

    and rapid eye movement (REM) sleep. NREM sleep if further divided into progressively deeper stages of sleep: stage N1, stage N2, and stage N3 (deep or delta-wave sleep). As NREM stages progress, stronger stimuli are required to result in an awakening. Stage R sleep (REM sleep) has tonic and phasic components. The phasic component is a sympathetically driven state characterized by rapid eye movements (rolling eyes, opening and closing), muscle twitches, and respiratory variability. Tonic REM is a parasympathetically driven state with no eye movements.

    • Word count: 6388
  13. Biotechnology Assignment: Genetic Screening/Testing

    2. Pre-symptomatic testing: For predicting or estimating risks of developing certain diseases such as Huntington?s or Alzheimer?s, 3. Conformational diagnosis of a symptomatic individual 4. Forensic/identity testing: To identify specific diseases from the trace evidence they leave 1. Diagnostic Testing: Diagnostic testing is used to diagnose or rule out a specific genetic or chromosomal condition. In many cases, genetic testing is used to confirm a diagnosis when a particular condition is suspected based on physical mutations and symptoms. Diagnostic testing can be performed at any time during a person's life, but is not available for all genes or all genetic conditions.

    • Word count: 2927
  14. An investigation of the effect enzyme concentration has on the rate of catalase activity

    Materials Refer to Handout. Procedure Refer to Handout. Variables Independent Variable: Amount of Catalase Dependent Variable: Volume of oxygen gas produced Controlled Variables: The numbers of discs are controlled to enable the noting of difference in volume of oxygen gas produced. The amount of hydrogen peroxide, the substrate is controlled to be 10.0mL so that the effect of substrate concentration is not recorded as changing the rate of reaction. The difference in the intervals recorded for time is consistent because it makes it easier and more distinct to see if there is a pattern in the volumes recorded.

    • Word count: 1585
  15. Therapeutic Uses of Stem Cells

    The major purpose of the production of embryonic stem cells is for therapeutic treatments on living organisms such as humans or animals. Scientists that attain the right conditions for these cells are able to cultivate them for repair or replacement of injured, diseased, or dead organs and tissues.

    • Word count: 466
  16. The Effect of Indicators on the presence of Macromolecules in a McMush slurry

    Carbohydrates are used by living organisms as an important source of energy. Examples of carbohydrates include glucose, fructose, sucrose, galactose, ribose, deoxyribose, cellulose and chitin. Lipids are made of carbon, hydrogen and oxygen (CHO) is not 1:2:1. Instead, lipids have a much higher number of carbons and hydrogens with few oxygen atoms present. The nonpolar bonds that form between the carbon and hydrogen atoms of a lipid cause them to be hydrophobic, or water-repellent, molecules. This explains why water and oil do not mix. The large number of carbon to hydrogen bonds also serves to make lipids energy rich storage molecules.

    • Word count: 1079
  17. Talking Parrot - review of "Alex and Me" by Irene Pepperberg

    I love you.? Pepperberg compared losing Alex to be the same as losing her baby several years earlier. People all around the world who were touched by Alex wrote in to Irene sending their condolences. Irene Pepperberg began her interest in birds when she received a baby parakeet for her 5th birthday. She can?t remember its name and it never talked, but it played with her and flitted around on her shoulder wherever she was in their house. She grew older and kept getting more birds, with her first bird to talk being Charlie Bird number one. The summer before her senior year, she was in an introduction course at MIT for chemistry.

    • Word count: 1147
  18. Beet Lab. Aim: To determine the effects of temperature on the permeability of the beetroot cell membrane.

    Any damage to the cell membrane will cause the cytoplasm to leak out of the cell. Energy for the movement of molecules comes from the kinetic energy of molecules. Cell membranes are composed of phospholipids and proteins, which contribute to the selectively permeable nature of the membrane. Small, uncharged molecules can diffuse across the membrane, while certain other substances must be transported across the membrane by proteins. Since the membrane is impervious to some substances except through channel proteins, important solutes can be retained. Beet cells, which are plant cells, contain a water-soluble pigment called betacyanin that is stored in the vacuole.

    • Word count: 2234
  19. Finding the isotonic point for potato tissue

    3.01 + 0.05 2.97 3.03 + 0.06 2.90 3.04 + 0.14 2.91 2.98 + 0.07 2.80 2.86 + 0.06 2.87 2.96 + 0.09 + 1.69 + 2.02 + 4.83 + 2.41 + 2.14 + 3.14 + 2.70 1.04 0.4 2.90 2.84 -0.06 2.87 2.83 -0.04 2.76 2.73 -0.03 2.84 2.77 -0.07 2.83 2.79 -0.04 2.90 2.81 -0.09 - 2.07 -1.39 -1.09 -2.46 -1.41 -3.10 -1.92 0.69 0.6 2.97 2.81 -0.16 2.98 2.74 -0.24 2.99 2.78 -0.21 2.91 2.80 -0.11 2.97 2.79 -0.18 3.00 2.77 -0.23 -5.39 -8.05 -7.02 -3.78 -6.06 -7.67 -6.33 1.45 0.8 2.81 2.61 -0.20 2.88 2.63 -0.25

    • Word count: 2604
  20. How does the concentration of hydrogen peroxide affect the time (s) it takes the enzyme catalase to decompose it into water and oxygen gas?

    Controlled: 1. Mass (in grams) of pureed cow?s liver (catalase) 1. Each test will use 10 grams of pureed cow?s liver, containing the enzyme catalase. 2. If uncontrolled, the reaction time could be either increased or decreased because of the changed amount of the catalyst, create imprecise data. 1. Temperature 1. The lab will be kept at a constant temperature of 20 degrees Celsius. 2. Temperature is a primary factor affecting both enzyme activity and reaction speed.

    • Word count: 458
  21. Investigating the Effect of Increasing Exercise in Aerobic Respiration

    For example, for the Flask #1; 64 ml x 10 = 640 μmol, for Flask #2; 68 ml x 10 = 680 μmol … Before Exercise After Exercise Trials for Experiment Flask # 1 Flask # 2 Flask # 3 Flask # 1 Flask # 2 Flask # 3 NaOH added (± 1 ml) 64 68 56 84 97 66 CO2 produced (± 10 μmol) 640 680 560 840 970 660 Table 1: The results for the effect of 2 minutes of exercise on CO2 production Before Exercise After Exercise Trials for Experiment Flask # 4 Flask # 5 Flask # 4 Flask # 5 NaOH added (± 1 ml)

    • Word count: 1574
  22. Is the rate of passive transport through potato slices and saltwater and distilled water significantly different?

    Electronic balance (Error: ±.01g) 3. Table Salt (NaCl) 4. Potato 5. Corer 6. Knife 7. Distilled Water 8. Graduated Cylinder (±1mL) 9. Spoon 10. Balance paper 11. Ruler (± .1 mm) 12. Cups 13. 10 Plastic bags Procedure: 1. Core potatoes and cut them into 20 mm lengths. Cut 100 slices and put 10 slices in each plastic bag. 2. Set out 10 cup (5 for salt, 5 for water) and label them Cup 1 Distilled Water, Cup 1 Saltwater, etc.

    • Word count: 757
  23. What is photosynthesis?

    Chloroplasts can be found in the mesophyll, which is the ground tissue system of the leaves. The mesophyll consists of parenchyma cells who are specialized for photosynthesis. CO2 needed for photosynthesis enters the leaves through the tiny pores called stomata, which are mostly found on the lower layer of the leaf. The loosely arranged structure of the lower mesophyll layer with the stomata under it is the major site of gas exchange, since air can enter by way of stomata and can circulate freely in the leaf easily until it reaches the chloroplasts.

    • Word count: 1435
  24. Finding the vitamin C content of a lemon

    Then we had to determine the volume of lemon juice that is needed to decolorize the same amount PCPIP. This provided us with the concentration of vitamin C in the lemon juice. RESULTS We got separated into four groups and the results of all of the groups were in the end combined and the average was calculated. Our first result was that the indicator will change the color if we add 0.75 ml of 0.1 % C vitamin solution to it.

    • Word count: 408
  25. Biology SL Lab Report - Genetically Modified Crops and Health

    For my experiment to go through, I will need to travel to India. India is one of the cradles of rice cultivation and, also, the second most populated country in the world. Half of the population is fed by rice daily. Favorable locations for rice cultivation are moist and damp places near rivers. Because of this, the delta of the Cauvery river in south-east India is a good location for planting seedlings of rice plants. The rice in this area is perennial, meaning it lives long and is capable of re-growing without reseeding, year long.

    • Word count: 995

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.