Lecture 6

Question 1

Three Factor Test Cross

Answer 1

used to determine map unit distances between genes on the same chromosome

Question 2

Parental Phenotype

Answer 2

phenotype that occurs in the child that must have been the result of a chromosome that didn’t cross over; highest number observed is the parental

Question 3

Recombinant Phenotype

Answer 3

phenotype that occurs in a child when they inherit a chromosome that has undergone crossing over; less frequent/fewer observed

Question 4

Double Recombinant Phenotype

Answer 4

occurs when a chromosome observed in the offspring has crossed over twice; least common/smallest observed number

Question 5

Determining Gene Order

Answer 5

compare the parental (most numerous) and double recombinant (least numerous) to determine the middle gene

Question 6

Linkage Map

Answer 6

shows the map units between different genes; the number of map units corresponds to the probability that a crossing over will occur between the two genes

Question 7

Chi Square Test

Answer 7

tests the fit between a prediction and actual data 
sum of (((observed-expected)^2)/expected)
consult chart to see whether the variation is plausible or too large

Question 8

Degrees of Freedom

Answer 8

number of phenotypes minus 1

for example, if a flower can be red, pink, or white, the degrees of freedom are (3-1=2)