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

Osmosis Internal Assessment (Biology)

Extracts from this document...

Introduction

BIOLOGY INTERNAL ASSESSMENT STANDARD LEVEL OSMOSIS OSMOSIS IN POTATO STRIPS i. Aim To investigate the change in the mass of potato strips as a result of the process of osmosis in potato strips over varying periods of time. ii. Research Question How does time affect the mass of potato strips (measured in grams) when immersed in distilled water (H20) over a period of five hours at one hour intervals: 1 hour, 2 hours, 3 hours, 4 hours, and 5 hours? iii. Introduction Osmosis is the passive movement of water molecules from a region of high water concentration to a region of lower water concentration (lower solute concentration to higher solute concentration), across a partially permeable membrane.1 The plasma membrane is selectively permeable, and it controls the movement of substances in and out of cells, but water is able to move freely in and out of the cell, allowing osmosis to occur.2 Potato cells have selectively permeable membranes and therefore can be used to show the process of osmosis. As plant cells generally have a higher solute concentration than their surroundings (lower water concentration), when immersed in H20, the potato strips will be surrounded by a region of high water concentration since water has a solute concentration of 0.3 This would mean that the distilled water is hypotonic whereby it has a higher concentration of water than the potato cells, causing water to flow from the area of higher water concentration (water solution) ...read more.

Middle

Dispose of all used material appropriately. vii. Results Table 1. Initial and final mass of the potato strips after immersion in distilled water () over a period of five hours at one hour intervals Duration given for osmosis to occur (hours ? 1min) Initial and final mass of potato strips ?0.1g Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Initial Mass Final Mass Initial Mass Final Mass Initial Mass Final Mass Initial Mass Final Mass Initial Mass Final Mass 1.0 3.0 3.0 3.0 3.0 3.0 3.1 3.0 3.2 3.0 3.0 2.0 3.0 3.2 3.0 3.3 3.0 3.3 3.0 3.2 3.0 3.1 3.0 3.0 3.4 3.0 3.4 3.0 3.6 3.0 3.5 3.0 3.4 4.0 3.0 3.5 3.0 3.6 3.0 3.5 3.0 3.7 3.0 3.7 5.0 3.0 3.6 3.0 3.6 3.0 3.6 3.0 3.7 3.0 3.6 *Note that the initial mass of all the potato strips are the same Table 2. Mean, standard deviation, and 33.33% of the mean for the final mass of potato strips immersed in distilled water () Duration given for osmosis to occur (hours ? 1min) Mean, S.D, and 33.33% of mean of final mass of potato strips ?0.1g Mean S.D. 33.33% of mean 1.0 3.1 0.09 1.02 2.0 3.3 0.08 1.09 3.0 3.5 0.09 1.16 4.0 3.6 0.10 1.19 5.0 3.6 0.04 1.19 *As the Standard Deviation is less than 33.33% of the mean for all the values of final mass of the potato strips, it can be seen that these mean values are accurate. ...read more.

Conclusion

Way in which mass was measured The mass of the potato strips were recorded using an electronic weighing scale up to only one decimal place, thus resulting in minimal differences in data collection, making conclusions more general and vague. Using a weighing scale with up to two decimal places will allow the data collected to be more accurate. Frequency of data collection* The mass of the potato strips were recorded after immersion in distilled water for 1 hour, 2 hours, 3 hours, 4 hours, and 5 hours, meaning large gaps between the data points, causing conclusions to be less accurate as the data was less reliable, and trends were more general and rather vague. Collection of data should occur at half an hour intervals over a period of six hours, providing ample data to make detailed conclusions. 1 Andrew Allot. IB Study Guide: Biology Standard and Higher Level (2nd edition). UK: Oxford University Press, 2007. 2 Alberts B, Johnson A, Lewis J. Molecular Biology of the Cell (4th edition). New York: Garland Science, 2002. 3 M B V Roberts. Biology, A functional approach (4th edition). UK: Thomson Nelson and Sons Ltd, 1986. 4 Ibid. 5 Regina Bailey. "Diffusion and Passive Transport" About.com Guide. Biology. 11 May 2011. <http://biology.about.com/od/cellularprocesses/ss/diffusion_3.htm>. 6 Alberts B, Johnson A, Lewis J. Molecular Biology of the Cell (4th edition). New York: Garland Science, 2002. ?? ?? ?? ?? Biology Internal Assessment - Osmosis Page 1 of 11 ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Here's what a teacher thought of this essay

4 star(s)

****
An excellent investigation into the effect of osmosis on the potato chips.
The introduction gave a good scientific foundation for the investigation and was well laid out with relevant information.
The method was very thorough and gave enough detail for the investigation to be repeated.
One limitation to the experiment was the independent variable. By choosing time it left the scientific analysis a little basic as osmosis continuing to happen over time is rather obvious.
The analysis of the data was excellent. The graphs clearly shown the general trend of the results.

Marked by teacher Jon Borrell 22/05/2013

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. Marked by a teacher

    The effect of Pectinase Concentraton on the production of apple juice

    Results Fig 2. As seen in fig 2., the average volume of apple juice was used to plot the graph to illustrate the trends of the results. The error bars used also display the degree of accuracy and uncertainty of which the results can range in.

  2. Potato and Sweet Potato Water Potential in Different Sugar Solutions

    10% 2. 17.6% 3. -0.66% 4. -5.66% 5. -11.66% - For sweet potato: 1. 17.3% 2. 15% 3. 4% 4. -7% 5. -10.66% Graph 1 (Potato): Graph 2 (Sweet Potato): Conclusion: What was found was that the concentration of the sugar solution increased while the weight of the potato decreased and this therefore, supports the hypothesis.

  1. Biology Lab Report-Osmosis

    the potato cell, then water from the potato cell will move out into the solution, through the semi-permeable membrane by osmosis. This means that each cell of the potato chip will decrease in size and mass as water leaves the cell.

  2. To investigate the amount of protein present in different types of milk by measuring ...

    Almost milk contain casein, but the soya milk is a special kind of milk. This is formed from soy bean. Almost protein present in soy milk is soy protein, thus the soya milk contain very little casein or has lack of casein.

  1. Biology HL IA - Transpiration lab report

    Then, approximately one third of all leaves were cut, cutting places were immediately covered with nail polish. After 10 minutes of rest records were started to be taken every 5 minutes for a period of 25 minutes. Then, the same procedure was made with second third and last third of all leaves until the plant had no leaves at all.

  2. Biology HL IA - Photosynthesis of elodea lab report

    The bubbles that collected on the highest point of photosynthometer were pulled to the measuring pipette by pulling the plunge of syringe gently. The volume of the gas bubbles released was recorded (mL) and experiment was repeated 4 more times using the same position of lamp in order to obtain reliable results.

  1. Investigating an enzyme-controlled reaction: catalase and hydrogen peroxide concentration

    All measurements were taken so that the stopwatch was started once the rubber tubing was sealed and the stopwatch stopped once the manometer fluid had reached the base of the highest marked point. To judge accurately, the point at which the fluid reached the marked line, it was examined at

  2. Explain how water moves from the soil into the plant

    The process of water moving upwards the stem through the xylem tissues is called transpiration. As transpiration takes place, water diffusing into the air spaces from the spongy mesophyll cells takes its place. This sets up a concentration gradient across which the water moves by osmosis out of the xylem into the leaf.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work