Question

Human Mendelian Traits Like most complex organisms, humans possess an enormous number of genetically inherited characteristics. Some of these are Mendelian in nature, i.e., one gene with two alleles (one true dominant, one true recessive) producing two easily observed traits. You and your partner will evaluate yourselves and each other for your phenotypes, then list the appropriate genotype possibilities. If you are dominant for the trait then assume you are heterozygous unless you know your parents phenotype. 1. Rolling the Tongue: You can either roll your tongue to form a tube or you cannot do so. Tongue rolling (R) is dominant to non-rolling (C). The alleles are represented by the appropriate case of the letter 'R'. Your Phenotype _Your Possible Genotype(s) 2. Crossing Thumbs: Without thinking, quickly clasp your hands together so your fingers interlace. Is your left thumb on top of your right (dominant trait), or right on top of left (recessive trait)? NOTE: try doing it the opposite way, it will feel "weird". The alleles are represented by the appropriate case of the letter 'L'. Your Phenotype Your Possible Genotype(s). 3. Presence of Cleft Chin - Does your chin have a distinctive inward folding of the skin (think of John Travolta) or not. If so, you exhibit a dominant trait, if not, you are recessive. The alleles are represented by the appropriate case of the letter 'C. Your Phenotype Your Possible Genotype(s)_ 4. Ear Lobes: Does the lower margin of your ear attach directly to your head (recessive trait), or does it hang, forming a distinct 'lobe' (dominant)? The alleles are represented by the appropriate case of the letter 'F'. Your Phenotype Your Possible Genotype(s) 5. Widow's Peak: This term refers to a distinct downward point along the hairline around the center of the forehead. If prosent, you exhibit a dominant trait, if your hairline is straight across, you are recessive. The alleles are represented by the appropriate case of the letter W. Your Phenotype_ Your Possible Genotype(s) 6. Hair on Fingers: Hold your hands out straight and point the backs of your hands towards the light. Look along your fingers and see if there is hair on the fingers between the joints if present, this is referred to as "mid-digit hair" and is dominant, if no hair is present along the backs of the fingers, the trait is recessive. The alleles are represented by the appropriate case of the letter T. Your Phenotype Your Possible Genotype(s).

Answer 1

Q. 1. Phen R, geno r

Q.2. Pheno L , geno l

Q. 3. Pheno C , geno c

Q.4. Phen F , geno f

Q.5. Phen W, gen w

Q.6. PhenT, Gen t