What does it mean to say that two different species of organisms are closely related?

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

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

Match the description of each organism to the appropriate category