Question

Given the following data, what is the recombination frequency between these genes for squash color (red, yellow) and squash shape (log, oval)? What is the distance between the two genes in centiMorgans (or map units)? For full credit, you must show your work, i.e. how you made your calculations. (4 points)

Answer 1

Answer-

According to the given question-

Question 3-

Epistasis Here the phenotype for a particular traits or a phenotype of one gene is depends on the phenotype of the other gene which means that both the genes are responsible for controlling that particular phenotype or in other word we can say that the epistasis is defined when the locus of one genes responsible for particular phenotype changes or masks the phenotype of other genes.

Dogs have the gene responsible for their coat such as gene  TYRP1 and gene MC1R . both genes are responsible for controlling the expression of other gene. gene TYRP1 is produces the eumelanin which are color depend upon nature of gene. The  dominant allele of TYRP1 gene produces black eumelanin while the recessive allele of  TYRP1 gene produces brown eumelanin but the dog which are homozygous recessive for gene MC1R then there are no production of eumelanin this means that the dog have no colour so they appear as yellow or chacolate color. So we can easily understand that the those dogs that have the homozygous recessive gene MC1R will get yellow color either they have the gene TYRP1. so here we can say that both genes TYRP1 and MC1R are epistatic gane and show the phenomenon of epistasis. because the activity of gene MC1R are controlling the expression of gene TRYP1 and the phenotypic effect of gene TRYP1 is depends on the phenotype of gene MC1R. It can also be understand as that the dogs which have one dominant allele of gene MC1R then its genotype at the gene TRYP1 can be easily observed or seen and the dogs which have one domimant allele of gene TRYP1 the color od dog will be black and if it has two recessive allele for that genes then its color will be brown.

According to the information given in the question-

The fur color in a dog species of labrador is a polygenetic trait with epistasis and there are two genes and two allele for each genes.the Gene 1 contains coat colour one is Black which is dominant and represented as B while other id brown which is recessive and represented as b. While the second gene contains the pigment added to fur. one is dominant and represented by T while other is recessive and yellow color when no pigment is added and represented by t.

here we have to make a cross between

male having genotype BbTt (Black with pigmented fur ) with a female having genotype of bbTt (Brown without pigment or yellow color pigment)

BbTt   $\times$ bbTt

So here we can make a punnet square for this type of dihybrid cross with gametes are BT, Bt, bT, bt and bT, bt, bT, bt respectively from male and female parents so placing the data in table

	bT	bt	bT	bt
BT	BbTT (Black with added pigment )	BbTt (Black with added pigment )	BbTT (Black with added pigment )	BbTt (Black with added pigment )
Bt	BbTt (Black with added pigment )	Bbtt (Black with no pigment )	BbTt (Black with added pigment )	Bbtt (Black with no pigment )
bT	bbTT (Brown with added pigment )	bbTt (Brown with added pigment )	bbTT (Brown with added pigment )	bbTt (Brown with added pigment )
bt	bbTt (Brown with added pigment )	bbtt (Brown with no pigment )	bbTt (Brown with added pigment )	bbtt  (Brown with no pigment )

Here we can easily observed from the above table that from the 16 individuals the number of individuals having

Black with added pigment = BbTT or BbTT = 6

Black with no pigment= Bbtt= 2

Brown with added pigment= 6

Brown with no pigment= 2 (Yellow color dog)

Here we can observed that the number of brown color dogs are 6 out of total 16 so the probability of getting brown dogs out of 100 dogs= 6 / 16 * 100= 37.5 %

So the correct answer for the question is the probability of having a labrador retriver puppy from the cross made between a male having BbTt genotype with a female having bbTt genotype are 37.5 %

Question 4- Please provide data for this question related to the genes for squash color and squash shape so that we can easily get the answer. thanks.