To provide a tactile opportunity for students with visual impairments to construct a karyotype, an organized model of an organism’s chromosomes, showing the chromosome’s size and shape
Chromosomes in a cell are randomly arranged, except during cell division. To study chromosomes, scientists photograph the chromosomes while the cell is in the process of replicating. The scientists will then cut out the pictures of the chromosomes and organize them into pairs according to size and shape. A popular classroom activity is to give students photographs of human chromosomes and ask them to develop a karyotype. For a student who lacks the vision to see photographs, the clay chromosomes provide a tactile alternative. The number of chromosomes in an organism’s cells varies depending on the species of the animal. For example, the house fly has only 12 chromosomes.