Final answer:
Earthworms have a simple brain located in the anterior, or head region, which functions in sensory perception and the maintenance of internal body functions. Their brain is part of a larger nervous system including a ventral nerve cord that extends the length of the body.
Step-by-step explanation:
Yes, earthworms do have a brain, but it is much simpler than the human brain. The earthworm's brain is located at the anterior end of the worm, which is considered the head region. This structure allows them to sense and respond to various stimuli such as light and touch. Specifically, the brain in an earthworm is part of a nervous system that includes not only the brain but also a ventral nerve cord. The nervous system is responsible for many functions, including the maintenance of internal body fluid concentrations and movement.
In terms of anatomy, earthworms exhibit cephalization, which is the concentration of nerve tissue at one end of the body, forming a brain and head region. This evolutionary adaptation provides central control over the organism's sensory and nerve functions. The brain of an earthworm is connected to a ventral nerve cord that runs along the length of its body, coordinating movement and response to the environment.