6. Suppose that brown is the wild-type colour of the iris of eyes. However, dominant autosomal mutations in the genes coding the proteins responsible for the steps of colour determination (shown below) negatively disrupts their functions. The colour of the iris can be either blue, green, brown or no coloration (results in pink iris). B gene represents the pigment transporter; L gene represents the luciferase enzyme; and the C gene represents tyrosinase enzyme). The biochemical pathway for colour determination is the following: Cell of the human iris Blue Blue Luciferase (L) Green Pigment transporter (B) Tyrosinase (C) Brown a. Assuming no confounding factors, which genotype (include all genes mentioned) will result in green iris? b. Assuming that the transporter is composed of 4 subunits of protein coded by the same gene. What will the colour of the iris be if an individual is heterozygote for the gene expressing the transporter? c. Now, assuming the tyrosinase step is incompletely dominant and all the other steps are functional (homozygote recessive for step B and L), what will be the colour of the iris of the eyes?

6. Suppose that brown is the wild-type colour of the iris of eyes. However, dominant autosomal mutations in the genes coding the proteins responsible for the steps of colour determination (shown below) negatively disrupts their functions. The colour of the iris can be either blue, green, brown or no coloration (results in pink iris). B gene represents the pigment transporter; L gene represents the luciferase enzyme; and the C gene represents tyrosinase enzyme). The biochemical pathway for colour determination is the following: Cell of the human iris Blue Blue Luciferase (L) Green Pigment transporter (B) Tyrosinase (C) Brown a. Assuming no confounding factors, which genotype (include all genes mentioned) will result in green iris? b. Assuming that the transporter is composed of 4 subunits of protein coded by the same gene. What will the colour of the iris be if an individual is heterozygote for the gene expressing the transporter? c. Now, assuming the tyrosinase step is incompletely dominant and all the other steps are functional (homozygote recessive for step B and L), what will be the colour of the iris of the eyes?

Biology 2e

2nd Edition

ISBN:9781947172517

Author:Matthew Douglas, Jung Choi, Mary Ann Clark

Publisher:Matthew Douglas, Jung Choi, Mary Ann Clark

Chapter24: Fungi

Section: Chapter Questions

Problem 22RQ: Why are fungal insecticides an attractive alternative to chemical pesticides for growing food crops?...

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