Chapter 5, Problem 13P

Researchers cross a corn plant that is pure $\text{-}$ breeding forthe dominant traits colored aleurone ( $\text{C1}$), full kernel ( $\text{Sh}$),and waxy endosperm ( $\text{Wx}$) to a pure-breeding plant with

the recessive traits colorless aleurone ( $\text{c1}$), shrunken kernel( $\text{sh}$), and starchy ( $\text{wx}$). The resulting $\text{F1}$ plants were crossedto pure-breeding colorless, shrunken, starchy plants.

Counting the kernels from about $\text{30}$ ears of corn yields thefollowing data.

$\begin{array}{cc}KernelPhenotype& Number\\ Colored,shrunken,starchy& 116\\ Colored,full,starchy& 601\\ Colored,full,waxy& 2538\\ Colored,shrunken,waxy& 4\\ colorless,shrunken,starchy& 2708\\ colorless,full,starchy& 2\\ colorless,full,waxy& 113\\ colorless,shrunken,waxy& 626\\ & 6708\end{array}$

a. Why are these data consistent with genetic linkageamong the three genes?

b. Perform a $\text{chi-square}$ test to determine if these datashow significant deviation from the expected phenotype distribution.

c. What is the order of these genes in corn?

d. Calculate the recombination fraction between the genepairs.

e. What is the interference value for this data set?