Quiz 6

Question 1

In parakeets (Budgerigar, Melopsittacus undulatus) coat color is determined in part by one autosomal (not sex linked) gene with two alleles. Green is the dominant allele, Blue is the recessive.You are given a population of pure breeding green parakeets, and a population of pure breeding blue parakeets. What is the phenotype and genotype ratio of these two populations?

Answer 1

The green parakeets are 100% Green and their genotypes are 100% G/G. The blue parakeets are 100% Blue and their genotypes are 100% g/g.

Question 2

You breed individuals from the green population of individuals from the blue population to produce an F1 generation. You produce a statistically significant number of baby parakeets. What is the phenotype and genotype ratio of the F1 generation?

Answer 2

100% will be Green, and 100 % will have the genotype G/g

Question 3

You breed members of the F1 generation to each other to produce the F2 generation. You produce a statistically significant number of baby parakeets. What is the genotype and phenotype ratio of the F2 generation.

Answer 3

Around 75% will be Green, and around 25% will be Blue. For genotypes, 25% will be G/G, 50% will be G/g, and 25% g/g.

Question 4

You repeat the above experiment, but this time the parental generation has pure breeding white and green parakeets. The F2 generation has the following phenotype ratio 9/16 Green, 3/16 Blue, and 4/16 are white. The sex of the baby parakeets does not matter. What is the mode of inheritance:

Answer 4

Epistasis

Question 5

Lets say in Dwarves (you know with the axes and mining and stuff) height is determined by one sex linked gene. Normal sized is the dominant allele, shorter is a receive allele. Dwarves have an X/Y sex determination system like us. A shorter female Dwarf marries a normal sized male Dwarf. What is the genotype and phenotype of both parents?

Answer 5

The Female is phenotypically short and is homozygous recessive (s/s). The male is phenotypically tall and has a dominant allele and a y chromosome (S/y).

Question 6

What is the expected sex ratio of the children?

Answer 6

Half will be male and half will be female.

Question 7

What is the expected genotype and phenotype ratio of the female children produced?

Answer 7

All of the female children will be tall, and will be heterozygotes (S/s)

Question 8

What is the expected genotype and phenotype ratio of the male children produced?

Answer 8

All will be short, and will have a recessive allele and a y chromosome. (s/y)