Using our trial subscription to Explore Learning, Miss Em explored genetic inheritance using a Gizmo that allowed her to construct aliens and examine their offspring. She could change the skin colour of the aliens, give them straight or curly antennae, give them tattoos, and select their body size. By manipulating these characteristics and performing experiments to test her hypotheses, she learned about acquired traits (skin colour, antennae shape) versus inherited traits (tattoos are not passed down to offspring; body size depends on food availability – which could also be manipulated in the Gizmo).
She then learned that there are two copies of each gene, and one can be dominant over the other. In the case of the antennae, straight dominates curly and there is no “sort-of curly”. However, with colour, while one colour dominates the other colour shows up as spots. By manipulating colour, and crossing offspring back to parents, she was able to determine that Green dominates over Pink, and Blue dominates over Pink, and Green dominates over Blue.
We recorded our experiments, the variables we selected, and the outcome on paper. She soon learned to predict what combinations of traits would be seen in the offspring, and with what frequency (and she also learned that Nature doesn’t always follow the frequency exactly: the first four offspring will not necessarily represent all possible gene combinations).