Genetics Ch007

1. Questions and Problems, 7.1 Two yeast strains differing in three linked genes were digest over: A B C a b c. Among the tetrads that were analyzed, superstar contained the following spores: A B C, A b C, a B c, and a b c. How did this tetrad get down? autonomic nervous transcription: A two-strand double crossing voter must have occurred. Feedback: 7.1 obstacle: easy 2. Questions and Problems, 7.2 If two loci atomic number 18 13 cM apart, what proportion of the cells in pro chassis of the first meiotic division will contain a single crossover in the region in the midst of them? autonomic nervous system: 26%. Feedback: 7.2 Difficulty: easy 3. Questions and Problems, 7.3 Genes a and b are 20 cM apart. An a+ b+/a+ b+ individualistic was mated with an a b/a b individual. (a) diagram the cross and show the gametes produced by each set up and the genetic constitution of the F1. (b) (c) What gametes can the F1 produce, and in what proportions? If the F1 was crosse d to a b/a b individuals, what offspring would be expected, and in what proportions? (d) Is this an example of the duo or repulsion linkage phase? (e) If the F1 were intercrossed, what offspring would be expected and in what proportions?

Ans: (a) marker: a+ b+/a+ b+ a b/a b Gametes: a+ b+ from one parent, a b from the other F1: a+ b+/a b (b) 40% a+ b+, 40% a b, 10% a+ b, 10% a b+ (c) F2 from testcross: 40% a+ b+/a b, 40% a b/a b, 10% a+ b/a b, 10% a b+/a b (d) Coupling linkage phase (e) F2 from intercross: compend of phenotypes: a+ and b+ 66% a+ and b a and b+ 9% 9% a and b 16% Feedback: 7.1, 7.2 Diffic ulty: medium 4. Questions and Problems, 7! .4 From a cross between individuals with the genotypes Cc Dd Ee cc dd ee, 1000 offspring were produced. The household that was C- D- ee include cd individuals. Are the genes c, d, and e on the same or different chromosomes? Explain. Ans: The class delineated by 400 offspring indicates that at least two of the three genes are linked. Feedback: 7.1 Difficulty: easy 5. Questions and Problems, 7.5 If a is linked to b, and b to c, and c to d, does...If you motivation to get a skilful essay, order it on our website: BestEssayCheap.com

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