Trihybrid Cross Video Lessons

Concept

# Problem: A geneticist is using a three-point test cross to map three linked Drosophila recessive mutations called a, b, and c, where a is associated with anomalous gait; b is associated with buckled wings; and c is associated with curved bristles. She first crosses homozygous anomalous, buckled flies to homozygous curved flies. Next, she test crosses the F1 progeny to anomalous, buckled, curved flies. She obtains 1000 progeny distributed as the following results. From this data, calculate the map distance between a and c.

###### FREE Expert Solution

Genotypes: The genotypes of the given phenotypes are:

• gait = a+, a (anomalous gait)

• wings = b+, b (buckled wings)

• bristles = c+, c (curved bristles)

Parent Generation:

Female = a b c+

Male = a+ b+ c

###### Problem Details

A geneticist is using a three-point test cross to map three linked Drosophila recessive mutations called a, b, and c, where a is associated with anomalous gait; b is associated with buckled wings; and c is associated with curved bristles. She first crosses homozygous anomalous, buckled flies to homozygous curved flies. Next, she test crosses the F1 progeny to anomalous, buckled, curved flies. She obtains 1000 progeny distributed as the following results. From this data, calculate the map distance between a and c.