Is symbiosis a behavior that exists only between two differ animal

Which statement describes an endocrine function rather than an exocrine function? a. salivary glands release saliva into the mouth. b. sweat glands release sweat onto the skin c. the pineal gland releases melatonin into the blood. d. esophageal glands release mucus into the esophagus.

This is a scaffolding of protein fibers that us sell keep it shape in a cell division and cell movement

What are 3 reasons that natural selection occurs