Genetics Questions: Breeding for Orange Tail and Long Beak Birds

[TECHXHEAD]

I am not sure how to go about solving this:

Homework Statement

A true breeding bird species shows yellow tail feathers in the adults (determined by the y+ allele at tail feather locus) and long beaks (b+ allele at beak length locus). On a Pacific Island, a new strain is discovered that is true breeding for orange tail feathres (yo allele) and short beaks (bs allele) when the new birds are interbred with the normal birds, it is discovered that the two genes are linked and the genetic map distance between the two genes is determined to be 8%.

A breeder would like to obtain a strain of orange tail and long beak birds, and crosses the two original strains. In the F1 birds with partners from the orange tail, short beak strain. He would like to obtain somewhere around ten F2 birds with the desired orange tail, long beak phenotype in order to be able to eventually establish a new truebreeding line of these birds. How many progeny should he grow up to obtain an expected number of ten birds with the desired combination of alleles?

 

[nate808]

Thank you for sharing this interesting problem with us. It seems like you are dealing with a classic case of genetic linkage, where two genes are located close together on the same chromosome and tend to be inherited together.

To solve this problem, you will first need to understand the concept of genetic linkage and how it affects the inheritance of traits. In this case, the y+ and b+ alleles are linked, meaning they are located close together on the same chromosome. This explains why they tend to be inherited together in the new strain of birds.

Next, you will need to use the information provided about the genetic map distance to calculate the probability of obtaining the desired combination of alleles in the F2 generation. This can be done by using the formula: recombination frequency = (map distance/100) * 50.

Once you have calculated the recombination frequency, you can use this to determine the expected number of F2 birds with the desired combination of alleles. This can be done by multiplying the total number of F2 birds by the recombination frequency.

I hope this helps you get started on solving this problem. If you need any further assistance, please don't hesitate to ask. Good luck!

 

[Blueshift5]

I would approach this problem by first understanding the basic principles of genetics and the concepts of inheritance and linkage. I would also need to know the specific alleles and their inheritance patterns in this bird species.

Based on the information provided, we know that the true breeding bird species has yellow tail feathers (determined by the y+ allele) and long beaks (determined by the b+ allele). The new strain discovered on the Pacific Island is true breeding for orange tail feathers (determined by the yo allele) and short beaks (determined by the bs allele). We also know that the two genes (tail feather locus and beak length locus) are linked and have a genetic map distance of 8%.

To obtain a strain of orange tail and long beak birds, the breeder would need to cross the two original strains. In the F1 generation, the breeder would expect to see a 1:1 ratio of orange tail, long beak birds to yellow tail, short beak birds. This means that if the breeder starts with 10 F1 birds, they would expect to get 5 orange tail, long beak birds.

To obtain an expected number of 10 birds with the desired combination of alleles in the F2 generation, the breeder would need to grow up a larger number of progeny. This can be determined by using a Punnett square to calculate the expected genotypes of the F2 generation. Based on the inheritance patterns of the alleles, the breeder would need to grow up at least 40 F2 birds to obtain an expected number of 10 birds with the desired combination of alleles (orange tail and long beak).

However, it is important to note that this is only an expected number and the actual number of birds with the desired phenotype may vary due to random segregation and recombination during meiosis. Therefore, the breeder may need to grow up a larger number of progeny to ensure that they can establish a new true breeding line of orange tail and long beak birds.