Mitosis and Meiosis

Cells shape the basic unit of the life of dwelling organisms. For the continuous growth, the cells divide and give upward shove to new ones by cell division. There are two kinds of cell division that living organisms undergo. These are mitosis and meiosis. Mitosis entails the boom as well as the replacement if the somatic cells. On the different hand, meiosis involves the production of gametes or spores that are necessary in the reproduction of the organism. This experiment ambitions at observing mitosis, where mother or father cells divide to give rise to two daughter cells. Further, the test will also touch on meiosis the place the daughter cells have similar number of chromosomes as the adults.
Materials and methods
For this lab session, you will need:

Whitefish blastula

Some onion root tips, and Sordaria

A pencil

A paper

A light microscope

A chromosome to be used as a simulation kit

Method

The first approach is to observe mitosis. In this case, the slides are prepared and the onion tips observed under the 10X and 40X objective lens of microscope. The cells in each stage were identified and then sketched

Cell replication were then observed. High power objective lens was used and each cell was observed and then recorded.

The next stage was the simulation of meiosis where a simulation kit comes into play to demonstrate meiosis. Two strands of the similar color connected so as to begin the DNA replication of both the homologous pairs.

After that, the chromosomes were intertwined to show synapsis. The anaphase gets stimulated as the homologous pairs are separated. The homologous is stimulated by pushing the chromosomes into separate cells.

Finally, the prepared slides of the sordaria are observed under the light microscope and then identified as either 4:4 or asci. Crossover is seen and then recorded. Calculation is then made to determine the map units and percentage of each.

Results

Number of 4:4

Number of Asci Showing Crossover

Total Asci

% Asci Showing Crossover Divided by 2

Gene to Centromere Distance (Map Units)

53

64

117

27.35%

27.35

Sordaria

Comparison of Mitosis and Meiosis

Mitosis

Meiosis

Chromosome number of parent cells

Diploid (2n)

Diploid (2n)

Number of DNA replications

Once

Once

Number of divisions

One

Two

Number of daughter cells produced

Two

Four

Chromosome number of daughter cells

Diploid (2n)

Haploid (n)

Purpose

Growth and repair

Production of gametes or spores

Number of 4:4

Number of Asci Showing Crossover

Total Asci

% Asci Showing Crossover Divided by 2

Gene to Centromere Distance (Map Units)

53

64

117

27.35%

27.35

Cell replication

Cell Replication

Number of Cells

Field 1

Field 2

Field 3

Total

Interphase

42

36

47

125

61.27%

14 hours 42 minutes

Prophase

10

13

18

41

20.10%

4 hours 49 minutes

Metaphase

6

5

4

15

7.35%

1 hour 46 minutes

Anaphase

2

3

2

7

3.43%

49 minutes

Discussion and Conclusion

There is an observation of mitosis. The stages that were evident during mitosis were prophase, metaphase, the anaphase and the telophase. The prophase is the longest while telophase is the shortest. On the other hand, meiosis gets simulated and then crossing over goes on in Sordaria. The map from this can thus be determined. From the observation, it is seen that the gene to centromere distance in the Sordaria is 27.35 map units.