Question

In: Biology

You are evaluating genetic linkage between two autosomal genes in a dwarf breed of Nigerian goats....

  1. You are evaluating genetic linkage between two autosomal genes in a dwarf breed of Nigerian goats. At these genes, black fur (T) is dominant to tan fur (t) and pointed ears (R) is dominant to rounded ears (r). You mate true breeding parents and the F1 are TtRr. You conduct a testcross and generate the following phenotypes in the F2.  

Progeny                                                      Number

black fur, rounded ears                              425

tan fur, pointed ears                                   557

black fur, pointed ears                               146

tan fur, rounded ears                                 151

  1. Which alleles are linked on the homologous chromosomes of the true breeding parents?

b. What is the recombination frequency between the two genes?

Solutions

Expert Solution

Answer-

a) T and r alleles are linked on the chromosome of one true breeding parent.

t and R alleles are linked on the chromosome of other true breeding parent.

Genotype of F1 is Tr/tR. So, genotype of one true breeding parent will be Tr/Tr and other true breeding parent will be tR/tR.

b) Recombination frequency between two genes is 23.2%

The explanation is given below:

​​​​​​​


Related Solutions

How would experimental results of the rest cross establish linkage between two autosomal fruit fly genes?
How would experimental results of the rest cross establish linkage between two autosomal fruit fly genes?
You are interested in mapping the genetic distance between two phage genes. You know from your...
You are interested in mapping the genetic distance between two phage genes. You know from your genetics course that relative gene distance in both bacteria and eukaryotes can be determined by finding the recombination frequency of the two genes. You infect a bacterial cell with two phages (h+r+ and hr) and you plate the progeny phages onto a bacterial lawn containing both strains of bacteria susceptible to the h mutant phenotype.   a) Describe all the possible plaque phenotypes you would...
Mention any two autosomal genetic disorders with their symptoms.
Mention any two autosomal genetic disorders with their symptoms.
Genetic analysis has shown that three recessive genes d (dwarf), e (enlarged trunk) and f (fine...
Genetic analysis has shown that three recessive genes d (dwarf), e (enlarged trunk) and f (fine leaf) are all found on chromosome #1 of apple. When a plant that was heterozygous for each of these markers was testcrossed, the following 1000 progenies were obtained: wild type- 130 (+++) fine leaf- 19 (++f) enlarged trunk- 2 (+e+) enlarged trunk, fine leaf – 350 (+ef) dwarf -362 (d++) dwarf, fine leaf -1 (d+f) dwarf, enlarged trunk -16 (de+) dwarf, enlarged trunk, fine...
In a hypothetical breed of dogs, coat color is controlled by two genes. There are six...
In a hypothetical breed of dogs, coat color is controlled by two genes. There are six different coat colors in this breed: black, brown, cream, gray, silver, and tan. Consider the following crosses. Cross 1: Black females from a lineage of all black dogs are crossed with brown males from a lineage of all brown dogs. F1 males and females are all black. When F1 are intercrossed, F2 males and females are black or brown. Cross 2: Black females from...
Two-Point Mapping The general strategy used to determine the genetic distance between linked genes is to:...
Two-Point Mapping The general strategy used to determine the genetic distance between linked genes is to: 1. Make all of the genes of interest heterozygous in an individual or strain 2. Examine the gametes produced in the heterozygous individual(s) Using our example above. You have two pure-breeding lines of plants, one with green seeds and short height (GG tt) the other with yellow seeds and tall height (gg TT). You cross the two strains to make the genes heterozygous. What...
Two double heterozygous normal appearing corn plants for genes A (albino) and D (dwarf), where the...
Two double heterozygous normal appearing corn plants for genes A (albino) and D (dwarf), where the mutant phenotype is recessive for each gene, were crossed. What is the expected frequency of plants with a Green Dwarf phenotype in their offspring?
In the common bluebell, two linked, autosomal genes control flower color and plant height. With the...
In the common bluebell, two linked, autosomal genes control flower color and plant height. With the given information, find the expected F1 generation phenotypes and the frequencies of the F1 generation. B (blue flowers) is dominant to b (white flowers) T (tall plants) is dominant to t (dwarf plants) If the crossover frequency between the two loci is 26%, what will the expected F1 phenotypes and their frequencies from the following cross: a) BT//bt x bt//bt b) Bt//bT x bt//bt...
1. you are evaluating autosomal recessive condition A (alleles A and a) and B (alleles B...
1. you are evaluating autosomal recessive condition A (alleles A and a) and B (alleles B and b) which you hypothesize are on different chromosomes. You are given 7 wildtype (homozygous dominant) female flies and 7 male flies that are homozygous recessive. What genotypic ratio would you expect in the F1 generation produced? 2. you mate the F1 females with males that are homozygous recessive for both disease A and B to produce an F2 generation. What phenotypic ratio would...
You are studying recessive mutations of three autosomal, linked genes in guinea pigs: fur color (y,...
You are studying recessive mutations of three autosomal, linked genes in guinea pigs: fur color (y, yellow); fur texture (wv, wavy); ear size (l, large). The data in columns A and B was obtained from crosses of heterozygous F1 females with homozygous testcross males (recessive for all three traits). Column: A             B                      C                     D                        E F2 Phenotype # Observed Corresponding Genotype P or SCO or DCO Genotype Written in Correct Order on Homologs yellow 310 ywv+l+ P...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT