What Are the Possible Genotypes of the Bull and Cows in This Monohybrid Cross?

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In summary, crossbreeds between normal birds and creepers produce offspring with a 2:1 frequency of creeper vs normal.
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Chickens with shortened wings and legs are called creepers, when creepers are mated to normal birds, they produce half creepers and half normal birds. When creepers aremated to creepers they produce 2 creepers to 1 normal. Crosses between normal birds produce only normal offspring. How must thesee results be explained?



Determine the geotypes of the bull and the 3 cwos. Hornless is recessive when Cow A is mated with the bull, the calves are all hornless. When cow B is mated with the bull the calvbes are all hornless. When cow C is mated with the bull a horned calf results. Cow A is horned. Cow B is hornless and Cow C is hornless



Thanks any help will be appreciated
 
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  • #2
It is difficult to give hint without answering the question but here goes:

Call the creeper allel C and the normal one N, then a creeper may have genotype CN or CC, normal ones could be CN or NN. See what genoptypes the offspring would have assuming the different possible genotypes of the parents (you will have to assume that one genotype is letal in order to explain the "2 creeper 1 normal" frequency of the offspring of creepers corssed with creepers).


Call hornless allel H and the horns allel N, since hornless is recessive you know that all hornless cows must have genotype HH, using the results of the crossings you can easily figure out whether the others are HN or NN.
 
  • #3
Karma, first figure out which trait is dominant and if the parent are heterozygous or homozygous


gerben said:
(you will have to assume that one genotype is letal in order to explain the "2 creeper 1 normal" frequency of the offspring of creepers corssed with creepers).

No you don't. Creeper is probably dominant and the parent are probably heterozygous
 
  • #4
iansmith said:
No you don't. Creeper is probably dominant and the parent are probably heterozygous

but then you would get 3 creeper 1 normal (not 2:1)
 
  • #5
My bad. Maybe I should avoid answering question right after I wake up.
 

1. What is a monohybrid problem in genetics?

A monohybrid problem in genetics involves studying the inheritance patterns of a single trait from one generation to the next. This can be done by crossing two organisms that differ in only one trait and observing the traits that are passed down to their offspring.

2. How do you set up a monohybrid cross?

A monohybrid cross involves crossing two individuals that are heterozygous for a specific trait. This means that they have two different versions of the gene for that trait, one dominant and one recessive. The offspring will inherit one version of the gene from each parent, resulting in a 3:1 ratio of dominant to recessive traits in the offspring.

3. What is the purpose of performing a monohybrid cross?

The purpose of performing a monohybrid cross is to study the inheritance patterns of a single trait and determine the probability of certain traits being passed down to offspring. This can help scientists understand how traits are inherited and how different versions of genes interact with each other.

4. How do you calculate the probability of certain traits in a monohybrid cross?

To calculate the probability of certain traits in a monohybrid cross, you can use the Punnett square method. This involves creating a grid with the possible combinations of genes from each parent, and then determining the probability of each trait based on the ratio of dominant to recessive genes in the offspring.

5. What is the difference between a monohybrid cross and a dihybrid cross?

A monohybrid cross involves studying the inheritance of a single trait, while a dihybrid cross involves studying the inheritance of two traits at the same time. This means that in a dihybrid cross, there are four different versions of the gene being considered, resulting in a 9:3:3:1 ratio of offspring traits.

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