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

    A living cell would not survive if oxygen only penetrated 81.8% of the cell so this shows us that living cells need to be very small and have a large surface area to volume ration in order to survive and make sure all the essentials can diffuse quickly and easily all the way through the cell.

  2. 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.

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

    The subjects appeared to be annoyed and agitated and found it hard, heavy and tiring to hold their arm above their heart. For this experiment, the subject was required to hold the monitored arm directly in front of them, in line with their heart.

  2. Allelopathy. Open Investigation Will increasing the number of allelopathic sunflower plants effect the ...

    each plant - Plant and leaves are green - Sunflower plants have a greater height in comparison to the bean plants - Sunflower leaves are medium in size and green - Size of leaves are small - Presence of 3 leaves on each plant - Plant and leaves are green

  1. Biology Cell biology

    All steps were repeated for the temperature 30C, 35C, 40C, 45C and 50 C. 2.0 Data collection and processing 2.1.1 Raw data table- (table 5 raw data table) Table showing the time for a full hydrolysis reaction to occur at differing temperatures at what colour they were at the end of five minutes.

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

    8 in C Minor (Movement 3) 916,430 Symphony No. 5 (Movement 4) 359,685 Piano Sonata No. 8 in C Minor (Allegro of Movement 1) 381,600 Student 3 Song Score No Music 7,069,155 Serenade for Strings in C Major 4,986,270 Piano Sonata No. 8 in C Minor (Movement 2)

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

    I would ensure that all of my seeds smooth seeds that matched the dark olive green of the seeds below. I would also ensure that the length of the seeds was consistent at 5-6mm. Varying cotton wool thickness The cotton wool varied in thickness across the different petri dishes.

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

    As carbon dioxide is produced by the yeast cell the gas will rise as gas is lighter and less dense than the water and yeast solution, the foam we see is bubbles of gas the are trapped in the solution, this is only possible due to the slow dispersion of

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