15. Do you have a dimple in your chin? Yes or No = Partner A Partner B Having no dimples in your chin is a recessive trait. For the purposes of this exercise, if you have a dimple in your chin, you are homogynous dominant for this trait (DD). Absence of a dimple in your chin indicates a homozygous recessive genotype for this trait (dd). Complete the Punnett Square below and calculate the percentage probability of inheritance: Probability (percentage) of having Child with dimples? Child without dimples? PTC Tasting: Complete this exercise with a partner of the opposite sex. PTC (phenylthiocarbamide) is a bitter-tasting chemical found in some plants. Similar chemicals are found in broccoli and grapefruit. PTC is not found is human food, but if it was, it would be a powerful deterrent to eating that food. 16. PTC tasting is a dominant trait. People who can taste PTC very strongly are called supertasters". Most people (about 70% of most populations) are "tasters", but about 30% of any random group usually is made up of "non-tasters". Let's find out which YOU are. 1) Can you taste a slightly bitter taste when you eat brussel sprouts, broccoli and cabbage? a. Yes or No 2) If you answered Yes lets pretend you can taste PTC. If you answered No we'll say you cannot. 3) PTC tasting is a Dominant trait. If you can taste the PTC, your genotype for this particular allele is either TT (homozygous dominant) or T(heterozygous). For this experiment, if you can taste the PTC, your genotype for this trait is Tt If you cannot taste the PTC, your genotype is to Fill out the following Punnett Square with your and your partner's genotypes for PTC tasting: Probability (percentage) of having PTC-tasting child? % Non-PTC tasting child?