Question

4. Here we’ve performed a dihybrid testcross with a pizza a dihybrid that is thick crusted with BBQ sauce.

offspring phenotype	# of offspring
thin crust, traditional sauce	21
thin crust, BBQ sauce	130
thick crust, traditional sauce	125
thick crust, BBQ sauce	24

Based on this data, are these genes linked?

This is a dihybrid testcross. You know the phenotype of the dihybrid... given this information, what is the phenotype of the other mating partner in this cross?

Cool. So, based on this data, are these genes in a cis or trans arrangement in your dihybrid?

How many map units apart are the genes for crust thickness and sauce type?

FOR BONUS FUN (not part of the completion point for this HW)... take all of the information you have regarding these 3 pizza genes from questions 3 and 4 and draw a map.

Answer 1

Based on this data, are these genes linked?
The answer is
As The offspring observed values are not in 1:1:1:1 ratio, which indicates that these genes are linked genes.
.
.
This is a dihybrid testcross. You know the phenotype of the dihybrid... given this information, what is the phenotype of the other mating partner in this cross?
The answer is
Out of four categories the offspring with high frequencies are in represent the parental categories, so, the categories thin crust, BBQ sauce-130 and thick crust, traditional sauce-125 represent parental categories. So, the phenotype of dihyrids is

thin crust, BBQ sauce / thick crust, traditional sauce.
.
.
based on this data, are these genes in a cis or trans arrangement in your dihybrid?
The answer is
Trans arrangement.
.
.
How many map units apart are the genes for crust thickness and sauce type?
The answer is
Distance between the genes = Number of recombinants/Total number of progeny * 100.
= 21+24/300*100= 15cM