How to Calculate the Number Of Chromosomes in Mitosis

Mitosis is a method of cellular reproduction that involves the replication of a parent cell into two identical daughter cells. In humans, for example, the parent cell contains 23 pairs of chromosomes, which amounts to 46 individual chromosomes prior to replication. In order to produce two identical daughter cells, the parent cell must duplicate its chromosome number to 92 during mitosis. The chromosomes may then be equally divided between the two daughter cells. Different organisms contain different numbers of chromosomes; however, the process of genome duplication is essential for any species to carry out mitosis.

Things You'll Need

• Microscope
• Cell Staining Solution
• Living Tissue Sample

Show More

Instructions

Using a living tissue sample

• 1

  Locate an individual living cell in the organism you want to study. In order to visualize the process of mitosis, you need to employ special staining techniques and the use of a microscope.

• 2

  Identify which phase of the cell cycle your specimen is in. The majority of a cell's life is spent in a resting phase; cells only occasionally enter mitosis and always do so for a short period. This may make locating an actively dividing cell difficult. Additionally, mitosis requires condensation of the cell's genetic material into individual, distinguishable chromosomes. In fact, mitosis is one of the few periods of a cell's life span during which you can count the number of chromosomes by using a microscope.

• 3

  Count the number of individual chromosomes present in the cell.

Use the Known Chromosome Number

• 4

  Use the taxonomy browser (available in resources) to research the organism you want to study. The genus and species name are required for this step.

• 5

  Identify the number of chromosomes the organism you are studying normally has. Many species have already been studied to determine the number of chromosomes present in the parent cells (see resources). Use this information to determine the number of chromosomes present during mitosis.

• 6

  Multiply the cell's chromosome number by two. In order to create two identical daughter cells, the process of mitosis requires the precise duplication of the cell's entire genome. Therefore, the number of chromosomes during mitosis will be equal to 2x the cell's original chromosome count.