What does a fern ultimately depend on as an energy source

What is an endocrine function? (apex) a.esophageal glands release mucus into the esophagus b.salivary glands release saliva into mouth c.swear glands release sweat to the skin d.the pineal gland releases melatonin into the bloodstream

Which could be a pathway of food through an ecosystem

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