Question

Information for Questions 1-4. Smurfs are imaginary creatures popularized by a 1980's television cartoon. You are likely familiar with the village of blue-bodied Smurfs recently revived by in a Hollywood movie. However, you may be unaware that there also once existed a neighboring village of white-bodied Smurfs. Typically, the blue and white- bodied Smurfs remained in isolation due to a vast mountain range separating their villages. One year, however, several adventurous white-bodied Smurfs crossed the mountain range and stumbled upon the blue Smurf village. There they conceived several children with some of the blue-bodied Smurfs. Surprisingly, all of these children had PURPLE bodies! Over the years, these purple-bodied Smurfs kept to themselves and ultimately formed families amongst themselves. While most of their children were purple, the parents were sometimes surprised to discover that they had produced a blue bodied child or a white-bodied child. The ratio of body colors amongst the purple Smurfs children was approximately 9 Purple : 4 White : 3 Blue. Consider this information and answer the following 4 questions. 1. How many genes control body color in Smurfs? 2. Propose an enzymatic pathway for the development of body color in Smurfs by drawing out the pathway. 3. Which mutation is epistatic to the other? 4. If the genes are named after their mutant phenotype as they are in fruit flies (bb genotype produces blue body but BB and Bb genotypes produce a different color, for example), give the genotype of each of the Smurfs showing both alleles of all of their body color genes. A. Original Blue Smurfs B. Original White Smurfs C. Original Purple Smurfs Information for questions 5-6. You have crossed a true breeding red-flowered plant with a true breeding pink-flowered plant and discover that all of the offspring have red flowers. When you self-fertilize these red-flowered Fl plants, you find a ratio of 9 red- flowered plants : 7 pink-flowered plants among the F2 offspring. 5. How many genes control flower color in these plants? 6. Describe the requirement of each of the enzymes for flower color in these flowers. Hint: use a term like only one, both, either, neither, all three, etc....

Genetics smurfs worksheet
help with Genes, enzymatic pathways, and mutations

Answer 1

1) there are 2 genes which control the body color of the smurfs, so when the purple and purple are crossed there are blue, white and purple progenies and the ratio is

purple: white: blue=9:4:3

this is the ratio of recessive epistasis,

that is

having wild type allele for both genes: homozygous recessive for epistatic gene: homozygous recessive for hypostatic gene = 9:4:3

2) let the genes be A and B, A converts white pigment to Blue and the blue pigment is converted to purple by B.

gene A gene B White O White Pro Blue Blue gene B Purple Purn Purplo

3) according to the above pathway mutation in gene A is epistatic to gene B, that is when aa is present the phenotype would be white

4) based on question 4 bb is blue and BB and Bb produces different color  

so A) original  Blue parents are AAbb

B) original white smurfs are aaBB

C) orginal purple smurfs are AaBb ( formed by the crossing between these blue and white)