Pairs of socks are used to represent chromosomes in order to model the processes of mitosis and meiosis. By replicating socks to make sister chromatids and arranging them in stages, students can visualize how diploid cells divide and how haploid gametes are produced.

1. Gather 6–7 homologous pairs of socks, each pair distinct in color or pattern (e.g., two green pairs, two red pairs). Each homologous pair represents the same type of chromosome from two parents.
2. G1 Phase: Place one sock from each pair on the table to represent unreplicated chromosomes (single chromatids).
3. S Phase (Replication): Add the matching sock to each original sock so that each chromosome now has two identical “sister chromatids” (joined at the heel as the centromere).
4. Mitosis:
   1. Line up the duplicated sock pairs along the middle of the “cell.”
   2. Separate the sister chromatids and move them to opposite sides.
   3. Form two new identical “cells,” each with the same chromosome number as the original (diploid).
5. Meiosis (start with diploid cell):
   1. Line up homologous pairs of socks side by side.
   2. Separate homologous pairs into two cells (Meiosis I). Each new cell is haploid but with replicated chromosomes.
   3. In each haploid cell, separate sister chromatids (Meiosis II). This produces four haploid cells, each with one sock from each homologous pair.

Meiosis - Dr. Steve Griffiths:

• Begin with only one homologous pair to demonstrate the simplest case of diploid mitosis and meiosis.
• Increase to two or three homologous pairs to show independent assortment and genetic shuffling in meiosis.
• Have groups compare results of mitosis vs meiosis using drawings or charts.

• No hazards—safe classroom activity.
• Keep socks clean and organized for future use.

• What is the difference between diploid and haploid cells? (Diploid cells have two of each chromosome; haploid cells have only one.)
• How do the products of mitosis compare to the parent cell? (They are genetically identical diploid cells.)
• How do the products of meiosis compare to the parent cell? (They are genetically unique haploid cells.)
• Why does meiosis create genetic variation while mitosis does not? (Because homologous pairs shuffle and separate independently during Meiosis I.)