Question

what is the role of homoeotic genes in an organism?
they control the production of lactase.
they regulate the development and placement of body parts in an organism.
they form a silencing complex with microrna.

Explanation:

Homoetic genes are crucial in development. They are not related to lactase production (lactase is an enzyme for lactose digestion). Also, forming a silencing complex with microRNA is not their role. Their main function is to regulate the development and placement of body parts in an organism.

Answer:

They regulate the development and placement of body parts in an organism.