Answer Happy

Considering Chromosomes-CHAPTER 12 A. Make a Karyotype In this activity, chromosomes will be represented as socks. COLLECT 12 SOCKS from your house. These will represent a complete complement of 12 Chromosomes for species X. We will assume of species X, the 2n-6 and n-3. You have 12 SOCKS because we are assuming these chromosomes have already gone through replication in S phase and contain Sister Chromatids. 1. Cells used for karyotypes have already gone through S phase of the cell cycle (they are arrested in M phase, usually metaphase of mitosis,. Describe the appearance of a real chromosome at this stage in the cell cycle (condensed or decondensed, one chromatid or two) 2. As the "chromosomes" in this activity have come from cells that ha e already completed S phase, be sure that all of your "chromosomes" have two "chromatids"- use rubbe. bards as centromeres to hold the chromatids together. Pairs of socks that appear identical are homologous chromosomes (chromosomes which contain the same genes). Why do sexually reproducing organisms have two of each chromosome (i.e. where did each come from)? 3. Do all of your chromosomes have homologs? If not, what might this mean? Hint. are there any chromosomes in the cell that don't have an exact matching partner?