Which of the following are mainly cycled through the processes of photosynthesis and cellular respiration?

CO2, or Carbon Dioxide.

Carbon dioxide is taken in during photosynthesis and released during cellular respiration.

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.

Iwolud you, but i dont know what you are asking.