QUESTION 5 When determining the relative genetic distance between two genes, why
ID: 140711 • Letter: Q
Question
QUESTION 5
When determining the relative genetic distance between two genes, why is dihybrid back-cross preferable over traditional dihybrid cross?
9:3:3:1 phenotypic ratio is easier to work with than 1:1:1:1 ratio.
Genotypes of the offspring can be determined based on their phenotype.
Unlike the traditional dihybrid cross, dihybrid back-cross produces all possible combinations of genotypes.
All of the above
Why do we map genes?
To understand how genes interact with each other
Comparative genomics analysis
To determine the genotype of an organism
All of the above
a.9:3:3:1 phenotypic ratio is easier to work with than 1:1:1:1 ratio.
b.Genotypes of the offspring can be determined based on their phenotype.
c.Unlike the traditional dihybrid cross, dihybrid back-cross produces all possible combinations of genotypes.
d.All of the above
Explanation / Answer
Back cross is the cross with one of the parent or organism which have same genetic composition as of parent.
Back cross is used to determine the genotype of organism with unknown genotype ,and dihybrid back cross has 1:1:1:1 ratio with only 4 genotype and 4 phenotype .
So,option2 is correct- genotype of the offspring can be determined based on their phenotype..
Gene mapping is the method to determine locus of Gene and distance between genes. The essence of all genome mapping is to place a collection of molecular marker on to their respective position on the genome.
We map gene for all of the above reason-
To understand how genes interact with each other
Comparative genomics analysis.
todetermine genotype of organism