How do systems in organisms prove that organisms are related?

You can tell that an organism is related to another organism by looking at their DNA. If they are similar, they are related. Another way to see if they look similar. For example, we are related to chimpanzees because we look similar and have similar DNA.

the glands which are associated with each description is given below:

pancreas - is an endocrine and exocrine gland that secretes juices with enzymes for digestion. salivary glands- with protection and digestion in the mouth. liver- secretes bile for digestion.   lachrymal glands - secrete tears to moisten eyes and protect them from particles and infection.   sweat gland -regulates water, salt, and temperature. oil glands - to form a protective barrier on the skin.   goblet cells - secrete mucus for protection.