Question

The purple spots on colorless background of corn kernels observed by Barbara McClintock were the result of _______.

a) environmental factors

b) transposition of the Ds elements into the color gene

c) mutation in the transposase gene

d) transposition of the Ds elements out of the color gene

Answer 1

The purple spots on colorless background of corn kernels observed by Barbara McClintock were the result of transposition of the Ds elements into the color gene.

Step-by-step explanation:

The purple spots on colorless background of corn kernels observed by Barbara McClintock were the result of transposition of the Ds elements into the color gene. McClintock discovered that the Ds (Dissociator) gene could change position within the chromosome and disrupt the function of the Bz gene responsible for kernel color. This transposition resulted in some aleurone layer cells producing purple pigment, creating the spotted or streaked phenotype.