DNA has a negative charge because of the phosphate ions in its chemical backbone.
Homeostatic regulation involves three parts or mechanisms: 1) the receptor, 2) the control center and 3) the effector. The receptor receives information that something in the environment is changing. The control center or integration center receives and processes information from the receptor.
Temperature regulation in the body is maintained but the brain stem. They hypothalamus of the brain controls hydration in the body. Both help maintain homeostasis.