Question

What is the maize kernel phenotype (visual appearance) when a Ds element jumps out of a gene coding for red/purple pigmentation relatively late during seed development?

(This is assumed to restore the original color to the kernel.)
a Colorless (yellow) kernel
b Yellow kernel with red/purple spots
c Dark purple, almost black kernel
d Completely red kernel

Answer 1

The maize kernel phenotype is a mosaic kernel with dark spots/streaks against a colorless background when a Ds element jumps out of a gene coding for red/purple pigmentation relatively late during seed development.

Step-by-step explanation:

The maize kernel phenotype (visual appearance) when a Ds element jumps out of a gene coding for red/purple pigmentation relatively late during seed development is a mosaic kernel with dark spots/streaks against a colorless background.

This occurs because the Ds gene can cause chromosomal damage in some aleurone layer cells, resulting in an inactivated C' allele. Without a functional C' allele, these cells revert to producing brown pigment directed by the bz allele. When these cells divide, they create clusters of brown cells surrounded by cells with an active C' allele, creating the appearance of pigment spots or streaks in the kernel.