Each student begins with a packet of cards that are the genetic inheritance of their "critter." The cards are color-coded by trait, with two cards for each trait (to simulate the alleles for each gene). We use 5 traits, so each student begins with 10 cards; we give all students the same initial genetic material. Before the game starts, have students draw a picture of their crit- ter based on the traits from their cards (use the template in Figure 1 (see page 506) to insure more consistent pictures; This will be important during later generations for comparisons of crit- ter offspring.) Drawing the critter is a good way to be sure that students understand the expres- sion of dominant vs. recessive, and mixing genes. The picture of the starting critter is given in Figure 2 (see page 507). (The gene cards we use are given on Master Sheets 1-5 (see pages 508-512); others could be used. We reproduced the sheets on lightweight cardstock, using a dif- ferent color for each trait.)