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

Do the different dilutions of yeast cell suspension affect the number of yeast cells per cm3 that counted using haemocytometer under the microscope?

Extracts from this document...

Introduction

DCP & CE Title The effect of the different dilutions of yeast cell suspension on the number of yeast cells per cm3 that counted using haemocytometer under microscope. Aim To investigate the effect of the different dilutions of yeast cell suspension on the number of yeast cells per cm3 that counted using haemocytometer under microscope. Research Question Do the different dilutions of yeast cell suspension affect the number of yeast cells per cm3 that counted using haemocytometer under the microscope? Introduction ?The typical yeast cell is approximately equal in size to a human blood cell?[1]. It is so small and present in such huge number that it is hard to be counted. To verify accurately the number of yeast cells, a haemocytometer need to be used as it is the most suitable for counting microorganisms under the microscope. Haemocytometer has a grid that is etched into the glass. The grid is an arrangement of squares of different sizes that allows for an easy counting of cells. It is also carefully crafted so that the area bounded by the lines is known, and the depth of the chamber is also known. Thus, it is possible to determine the number of cells in a specified volume of fluid. Hypothesis As yeast cell suspension become more diluted, the number of yeast cells per cm3 that counted using haemocytometer under the microscope decrease. ...read more.

Middle

1. Loading the haemocytometer 1. The yeast cell suspension is gently shaken and well stirred to ensure the suspension is properly mixed. 2. The end of capillary tube is inserted into the suspension and risen the liquid into the tube. 3. The end of capillary tube is run along the edge of the cover slip between the arms of the ?H?. The area between the cover slip and the top half of the ?H? is filled with the suspension. 4. The slide is turned through 180O and repeated for the opposite edge of the cover slip. 5. The haemocytometer is placed on a damp tissue in a petri dish for at least two minutes to equilibrate. 1. Counting the cells 1. The haemocytometer is placed on the microscope stage. 2. The grid lines of the haemocytometer are focused using the 10X objective of the microscope. 3. The numbers of cells in the area of primary squares are counted using a hand tally counter. 4. The haemocytometer is moved to another primary squares and the counting is carried on until all 4 sets of primary squares are counted. 5. Steps 1-12 are repeated using each of the serial dilutions. 6. The number of yeast cells in the original yeast suspension into cells/cm3 is estimate. Quantitative Data Test tube Dilutions of yeast suspension Number of yeast cells per cm3 that counted using haemocytometer under microscope. ...read more.

Conclusion

Conclusion The number of yeast cells per cm3 that counted using haemocytometer under the microscope decrease when the yeast cell suspension becomes more diluted. This means that there is a larger proportion of water compared to yeast suspension, which explains why there are less yeast cells per cm3 in a diluted suspension. Thus the hypothesis is accepted. Evaluation Limitation and Weaknesses 1. The yeast cells did not spread equally in the central main grid of haemocytometer. Therefore, the result obtained is not precise and not reliable. 2. The process of counting the yeast cells under the microscope is not repeated. 3. The counting of yeast cells that touched the chosen two grid lines are not consistent in every observation. Some observation used the top and right grid lines while the other observations used the bottom and left grid lines. Suggestion 1. The yeast suspension must be stirred thoroughly before being dropped into the haemocytometer. This to ensure that the cells would spread equally and consistently in the haemocytometer. 2. The counting should be repeated at least three times to get certain yeast cells counted by calculating the average of the counting from each observation. 3. Only two grid lines should be considered as the area for counting the yeast cell. It is either top and right lines or bottom and left lines. ________________ [1] I S Dept (2006). What Is Yeast: http://www.dakotayeast.com/yeast_what.html, visited August 3, 2012. ...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

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. The effect of the tempereature on yeast metabolism.

    that, with an increase in temperature, the rate of reactions will increase. This is due to the increase of speed of the particles, brought about by the extra energy given to them by heat. The faster particles will bring about more particle collisions and so the reaction will take place faster.

  2. Modelling Surface Area to Volume Ratio in Cells with Agar Cubes

    4. Write down any qualitative observations you see. 5. After 6 minutes, take the agar cube out onto a paper towel and cut the cube in half. 6. Using a ruler, measure the uncoloured and coloured areas of one side of the cube. 7. Calculate the volume and record all your results.

  1. Stimuli and Response. Investigation Question: How do different tempos of music affect response ...

    8 in C Minor (Allegro of Movement 1) Suspenseful, intense, fast, loud Student 2 Song No Music Quiet Serenade for Strings in C Major Light as a feather Piano Sonata No. 8 in C Minor (Movement 2) Slow, moderately content Violin Concerto No.

  2. How are interactions between neural cells established and maintained?

    It is the interactions between the growth cone and the surrounding structures and chemicals that govern the route along which the axon grows. Chemotactic guidance is the name given to guidance derived from close physical contact between the growth cone and structures it comes into contact with.

  1. Research Question (RQ) How does the position of the arm (cuff) in relation ...

    This resulted in three values for both systolic and diastolic pressures for each subject. Method for controlling variables: - Environmental conditions: * The aim to control the environmental conditions is to carry out the tests under similar weather conditions. The experimental tests were also run at roughly the same time of day so as not to disadvantage the participants.

  2. How does the salinity of water affect the germination of mung been seeds as ...

    The solutions we were adding to our seeds with the exception of 0.0 contained water and dissolved NaCl. When dissolved in water the ions in the salt dissociate resulting in the ions Na+ and Cl- to be present in the water.

  1. How does changing the percentage of sucrose added to yeast affect the rate of ...

    with a more accurate value of 16mm and thus we were able to preserve more of the integrity of our data and reduce the size of our error bars for that trial. There was another abnormality in our results which we kept in our calculation, this outlier occurred during the

  2. Overview of Cells & Energy (Revision)

    Rough sort contains ribosomes which stud the outer surfaces. Manufactures and transports proteins. Smooth Endoplasmic reticulum: stores proteins, but does not have ribosomes Turgid: plant cell turning stiff Turgor pressure: pressure inside the cell Vacuole: stores excess liquids Two similarities between prokaryotic and eukaryotic: both contain a cell membrane, two phospholipid sheets.

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