Question

In a certain flowering plant long leaves are dominant to short, and purple petals are dominant to white. The leaf length gene and the petal color gene are linked. A cross is conducted: Ll Pp X ll pp. The following offspring are produced: 44 long leaf & purple petal, 42 short leaf & white petal, 8 long Leaf & white petal, 6 short leaf & purple petal. What is the estimated distance between the two genes?

a. 10 map units
b. 20 map units
c. 30 map units
d. 40 map units

Answer 1

The estimated distance between the two genes is 24.1 map units, which is closest to option d. 40 map units.

Step-by-step explanation:

The estimated distance between the two genes can be determined by calculating the recombination frequency. Recombination frequency is the percentage of offspring that show combinations of traits different from those seen in the parents. In this case, there are 44 long leaf & purple petal, 42 short leaf & white petal, 8 long leaf & white petal, 6 short leaf & purple petal offspring. The recombination frequency can be calculated by adding the number of recombinant offspring (short leaf & purple petal + long leaf & white petal) and dividing it by the total number of offspring. In this case, the recombination frequency is (6 + 8) / (44 + 42 + 6 + 8) = 0.241. Since one map unit is equivalent to a recombination frequency of 1%, the estimated distance between the two genes is 24.1 map units. Therefore, the correct answer is d. 40 map units.