Asked by Jaclyn Franco on Jun 25, 2024
Verified
You want to determine if black coat color (B) and long tail length (T) are linked in a new breed of dog (white coat and short tails are recessive). Design a two-point test cross to determine if this is indeed the case. What results would you expect if the genes were linked? What would you expect if the alleles sorted independently?
Two-Point Test Cross
A genetic cross performed to determine the linkage between two genes by crossing a homozygous recessive individual with a heterozygous individual for those two genes.
Alleles
Different forms of a gene that can exist at a specific locus on a chromosome, contributing to genetic variation within a population.
Independent Assortment
The principle by Mendel stating that genes for different traits can segregate independently during the formation of gametes.
- Understand the theoretical foundation and practical implications of test crosses in studying genetic linkage and inheritance patterns.
Verified Answer
EC
Elisha ChopraJun 29, 2024
Final Answer :
Concepts to Consider: A two-point test cross is a dihybrid cross between an individual that is heterozygous for both traits and an individual that is homozygous recessive for both traits. If the genes for alleles B and T are not linked, a 1:1:1:1 ratio of all possible phenotypes will be observed in the F1 generation. Any deviation from this ratio will indicate gene linkage. In complete linkage, only parental phenotypes will be observed in the F1 generation.
Learning Objectives
- Understand the theoretical foundation and practical implications of test crosses in studying genetic linkage and inheritance patterns.