Final answer:
The incorrect statement is D. segment polarity genes regulate pair-rule genes. The correct hierarchical sequence is maternal effect genes activate gap genes, which activate pair-rule genes, and these regulate segment polarity genes in Drosophila embryogenesis.
Step-by-step explanation:
The relationship that is INCORRECT is D. segment polarity genes regulate pair-rule genes. During Drosophila embryogenesis, the hierarchy of genetic interactions typically goes as follows: maternal effect genes activate gap genes, gap genes activate pair-rule genes, and pair-rule genes regulate segment polarity genes. Each of these genes plays a vital role in the development of segmental patterns in the embryo. Specifically, maternal effect genes are the first in the sequence, providing instructions for the development of the embryo; these subsequently activate gap genes which define broad areas along the anterior-posterior axis. Pair-rule genes are then expressed in alternating segments and further define the segmentation pattern. Lastly, segment polarity genes refine the segmental pattern and contribute to the development of anterior-posterior patterning within individual segments, but they do not regulate the pair-rule genes. Therefore, the statement that segment polarity genes regulate pair-rule genes is false.