What is the driving force within an ecosystem?

20 in the formula no3, what does the subscript 3 mean?

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

The science for classifying and naming organisms is known as