Lab Report №3
By Yerkebulan Yesbolatov
Biology course, tutorial group I
October 18, 2012
Lab partner: Azhar Zhaisanova
Experiment is intend to show mitotic stage of cell cycle, phases of mitotic stage, to define predominance in the number of each phases over the others, if it is possible. Objectivity of lab is to observe the different phases of mitotic stage of cell cycle, to get skills for special technique( by using orcein ethanoic stain) designed for making slide enable to observe mitotic stage of cell cycle. The tip of Garlic bulb’s root is suspected to be relevant for that, for observing the cell cycle. Aim
To observe cell cycle in definite stage-in this experiment mitosis. To get knowledge of which phase is predominate in cell cycle. Precautions
During the procedure it is need to wear eye protection cause hydrochloric acid is irritant It is necessary to wear gloves and coat – Toluidine blue is had ability to ingrain. Don’t ingest- it is harmful. It is necessary to wear goggles and avoiding of content with orsein ethanoic stain, cause it corrosive, irritant, causing burns, has ability to irritate by vapour. In case of making contact immediately necessary to wash with water for 10 minutes. It is necessary to wear eye protection and avoid a skin contact, cause Acetic alcohol is corrosive and highly flammable
Methods and Materials
First method of staining is cancelled. Second method with 1-st step was provided in advance. First, several root tips was cut off, added to watch glass with acetic alcohol(2cm3) for 10 minutes. Then, specimens transferred to second glass, which contain 5cm3 ice cold water,4-5 minutes are needed to wait after that. Later on specimens, dried off with filter paper. Next step, in order to haven’t damage a specimen ,it was poured with pre-heated hydrochloric acid rather than putting the pattern to test tube and vice versa till 5 minutes. Next step is to repeat step with acetic acid (2cm3) for 10 minutes in a watch glass. After 10 minutes, specimen (one of several) was put to glass slide then poured with 1-2 drops of stain called acetic orcein stain, it should cover whole surface of pattern. Note that to stain the wall would be better to leave specimen in a dye more than 2 minutes. Finally, specimen is covered with coverslip and pushed under the filter paper, put to microscope and observed. Result
Question 1 is in separate page
Question 2 Number of cells viewed under visible area x400.
Table of numbers of cells at field of view
Total number of cells
| Names of mitosis phases
| № in each stage
Question 3. Percentage in each stage of mitosis
Interphase =138172x100%= 80.232%
Ranking of stages of cell cycle
As it said, preparation freezed at one time.
Most of cells, about 90% of cell and consequently 90% cycle cell spent in interphase, it is proved by findings. Roughly 20 percent, approximately quarter of interphase are taken by prophase, metaphase, anaphase, telephase.
Question 4 Mitotic index
Mitotic index=28+3+2+1172=34172= 0.197
Mitotic index enable to find a tendency to grow of cells. It is mean that how cell is divide, at which rate it is reproduces.
Question 5 Reliability and validity
If centromeres of chromosomes are draw up at equator, we definitely could say it is metaphase, if we see sister chromatids at inverse poles we could say...
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