Final answer:
Homeotic genes, or Hox genes, are a class of genes that determine the body plan of animals by controlling the expression of other genes. They are arranged in clusters on chromosomes.
Step-by-step explanation:
Homeotic genes, also known as Hox genes, are a class of genes that play a crucial role in determining the body plan and development of animals. They contain DNA sequences called homeoboxes and encode protein transcription factors that control the expression of other genes.
Hox genes are arranged in clusters on chromosomes, with four clusters in vertebrates (Hox-A, Hox-B, Hox-C, and Hox-D). The arrangement of Hox genes on chromosomes reflects the anterior-posterior axis of an animal's body.