Final Exam Review - General Biology | BIOL 1001, Study notes of Biology

Download Final Exam Review - General Biology | BIOL 1001 and more Study notes Biology in PDF only on Docsity! Monohybrid crosses 1. The ability to roll the tongue inwards in humans is determined by the dominant gene R. From a couple both able to roll the tongue, a child is born. The child is unable to roll the tongue. What is the genotype of both parents? Explain your answer. a. The child must be a genotype rr, so the parents both MUST be Rr. 2. The ability for humans to taste a bitter chemical, phenylthiocarbamide (PTC) is due to the domininant gene T a. If one parent is a homozygous taster and the other is heterozygous, is it possible for them to have a non-taster child? i. Half of the offspring are homozygous tasters, and the other half are heterozygous tasters. ii. If both parents are heterozygous, is it possible for them to have a non-taster child? 1. Yes. They have a 25% chance 3. In some breeds of dogs, a dominant gene B controls the characteristic of barking while trailing sheep. If a breeder wants to produce a pure breeding strain of barkers, but knows that the allele for silent trailing b is present in her kennels, how would he determine which dogs to breed? Show your work. a. Identify the true breeding male dog, and then mate it with a female and if the children all bark, then they are homozygous dominant. 4. Hemophilia is an X related recessive disorder due to the recessive gene h. If an affected male mates with a heterozygous female, what percentage of their sons will be affected? What percentage of their daughters will be affected? a. 50% of the sons will be effected. b. 25% of the daughters will be affected.