Final answer:
Body halves typically develop in a dependent manner, directed by genetic instructions ensuring bilateral symmetry during embryonic development.
Step-by-step explanation:
The development of body halves in organisms, known as bilateral symmetry, typically happens in a dependent fashion. This means that the two halves of a body are not developing independently; instead, they are created based on the same set of genetic instructions. During embryonic development, a central line known as the primitive streak forms, and cells on either side develop in a mirrored pattern across this line.
Embryonic Development and Symmetry, These instructions for development are encoded in the organism's DNA. If the instructions are clear - that is, the genetic sequences do not have mutations that affect the symmetry - then the body halves develop in a synchronized and coordinated manner which is essential for proper form and function.