Mitosis is the asexual process of nuclear division that occurs in eukaryotic cells. Mitosis results in two nuclei that are genetically identical. It can occur in either haploid or diploid cells. Usually mitosis is followed by cytokinesis, such that each of the two nuclei ends up in a different cell.
Activity 1: Simulation of mitosis with clay chromosomes
a. Get a piece of white paper from the large roll to protect the lab bench.
b. Obtain modeling clay of two different colors.
c. Make two large replicated chromosomes, one of each color (the chromatids need not be firmly attached).
d. Make two small replicated chromosomes, one of each color, as above.
e. Review your notes, the textbook, and the poster showing mitosis in the lab.
f. Demonstrate the stages of mitosis with the clay chromosomes. (It helps if you draw the outline of cells, the spindle, etc. on the paper.
g. After answering the questions below, demonstrate mitosis with clay chromosomes to the instructor.
1. If an individual chromosome was rotated 180°, around any axis, during metaphase of mitosis, would the resulting daughter cells be any different than they would without the rotation? Explain briefly.
2. What are microtubule-organizing centers (MTOC's), and what is their function in mitosis and meiosis? Do all cells have them? What are centrioles? Do all cells have them?
Meiosis is the nuclear division that produces gametes in eukaryotic cells. Meiosis (accompanied by cytokinesis) results in four haploid cells that are each genetically different from one another.