Bio 202 EXAM 3 QUESTIONS AND ANSWERS VERIFIED 100% CORRECT A+ GRADED

Bio 202 EXAM 3 QUESTIONS AND ANSWERS VERIFIED 100% CORRECT A+ GRADED A dihybrid was test-crossed. 400 progeny were counted. How many would we expect in each phenotypic category? - ANSWER 100:100:100:100 A dihybrid test-cross was performed followed by a chi-square analysis. The p value was less than 0.05. What does this mean? It is likely that... - ANSWER The two genes are not independently assorting. Autosomal Recessive - ANSWER *look for children with unaffected parents 1. skips generations 2. males and females equally affected 3. rare Autosomal Dominnt - ANSWER *MUST have affected parent 1. does NOT skip generations X-linked recessive - ANSWER 1. affects more males 2. skips generation 3. never have father to son transmisson 4. unaffacted individuals have affected children x-linked dominant - ANSWER 1. males and females affected 2. no father to son transmission 3. an affected male passes to all his daughters A sex-linked recessive allele produces a red-green colorblindness in humans. A normal woman named Kate whose father was color-blind marries a color blind man named William. Of the girls produced from this couple, what proportion can be expected to be colorblind? - ANSWER 1/2 of the girls 2 hetero: incomplete dominance - ANSWER 1:2:1 phenotypic ratio 2 hetero: complete dominance - ANSWER 3:1 pheno ratio 2 hetero: co-dominance - ANSWER 1:2:1 pheno ratio Polymorphic - ANSWER "many forms" (two or more common wildtypes alleles in a population) *blood type Human leukocyte antigen (HLA) - ANSWER used to math bone marrow donor 0 it is a protein or marker found on body cells monomorphic - ANSWER When all individuals in a population are identical with regard to a particular trait All wild type or mutant Pleiotrophic - ANSWER an allele that affects several properties of an organism Penetrance - ANSWER number of individuals with a particular genotype that demonstrate the expected phenotype. i.e. 100% means complete penetrance Four people, clearly have the dominant allele, yet only 3 have the phenotype. - ANSWER 75% penetrance variable expressivity slide 24 - ANSWER range of expression of a given phenotype (the degree or intensity) Less than ? phenotypic classes indicates gene interaction - ANSWER 4 Mendelian ratio for two dihybrid cross with no gene interaction - ANSWER 9: both dom 3: one dom 3: one dom 1: both rec Mendelian ratio for two dihybrid cross with complementary interaction - ANSWER 9:7 Mendelian ratio for two dihybrid cross with dominant gene interaction - ANSWER 9:6:1 Mendelian ratio for two dihybrid cross with recessive epistasis - ANSWER 9:3:4 Mendelian ratio for two dihybrid cross with dominant epistasis - ANSWER 12:3:1 complementation test - ANSWER 1. Performed by crossing homozygous recessive mutants, and assaying for their phenotype 2. identifies how many genes are involved in a phenotype When two mutants with the same phenotype are crossed, and their offspring are wild-type then they are said to ? one another. - ANSWER complement what term best characterizes catabolite repression associated with the lac operon in E. coli? - ANSWER positive control T/F Lactose is an inducer of the lac operon - ANSWER True *lactose stimulates transcription of genes involved in its metabolism