BIOL 366 Mono and Dihybrid Crosses Recitation Problem Set Directions: For problems 1-6, do the following: A. List how many genes B. List how many alleles are involved. С. Identify symbols and genotypes/ phenotypes D. List the genotypes of the parents E. Diagram and complete a Punnett square F. Give the phenotype percentages/ration of the offspring. are involved 1. In dogs, erect eais (E) is dominate dogs have a litter of puppies? oopy ears (e). What are the results if two heterozyBous nt gene while the recessive gene results in the inability to roll the tongue (r). A man and his wife can both roll their tongues and are surprised to find that their son cannot. Explain this by showing t persons. (Note: you do not need to do a Punnett Square for this problem). the genotypes of all three rabbits, the recessive hairless allele (h) is embryonic lethal in the homozygous state in comparison to the dominant normal hair allele. Two heterozygotes cross. What are the phenotypic ratios of the rabbit pups born from this mating? In areas of the very deep and damp southeastern United States lives a giant flying cockroach known as a Palmetto bug. Assume that long antennae (L) are dominant to short antennae and that normal wings (N) are dominant to bent ones. What is the phenotypic ratio of a cross between an individual that is homozygous dominant for antennae and heterozygous for wings with an individual that is heterozygous for antennae and homozygous recessive for wings? 4. About 70% of Americans perceive a bitter taste from the chemical phenylthiocarbamide (PTC), The ability to taste this chemical results from a dominant allele (T) and not being able to taste PTC is the result of having two recessive alleles (t). Albinism is also a single locus trait with normal pigment being dominant (A) and the lack of pigment being recessive (a).A normally pigmented woman who cannot taste PTC has a father who is an albino taster. She has a child with a normally pigmented man who is a taster but who has an albino mother who does not taste PTC. 5. The following Punnett squares show the results of four different crosses Gregor Mendel made with pea plants. In this case, Mendel was looking at flower color with Red (R) being dominant over white (r). Match the letter of the cross with the number of the appropriate Punnett square. (don’t need to do steps D-F here) 6.