Review the section Investigating Life Heredity and the Hungr

Review the section \"Investigating Life: Heredity and the Hungry Hordes. \"A researcher is curious if Bt resistant bollworms are susceptible to an insecticide called DDT Bollworms susceptible to DDT have genotype it, while bollworms resistant to DOT have genotypes Tt or TT in an effort to better understand how these two genes are inherited, the researcher crosses an RR tt bollworm with an rr TT bollworm to produce the F_1 generation. Then, the researcher crosses the F_1 generation to produce an F_2 generation. What proportion of the F_2 generation is resistant to both Bt and DDT? Fill in the Punnett squares by dragging and dropping alleles to the answer boxes, first to predict the offspring in the F1 generation and then to predict the offspring in the F2 generation. Then fill in the blanks at the bottom using the product rule. (Assume that the genes that determine DDT resistance and Bt resistance are on different chromosomes.)

Solution

   Allele combination based on given genotype RRtt & rrTT

Bt

F₁

        

DDT

F₁

  

Bt

F₂

DDT

F₂

3/4 3/4 9/16

----------------------------------- X ------------------------------- = ----------------------------------

Proportion of F₂ generation Proportion of F₂ generation Proportion of F₂ generation

that is Bt resistant   that is DDT resistant that is

  both Bt and DDT resistant