Photosynthesis puts oxygen in the atmosphere.
It is stored in the hypothalamus, but is secreted by the pituitary gland. Hope this helped!
Unicellular organisms are organisms which contain single cells , they include bacteria, archaea, protozoa, unicellular fungi, unicellular algae among other organisms. Multi cellular organisms are those organisms made of made up of many cells these includes plants and large organisms. Unicellular organisms are believed to have formed from non-living elements approximately 3.5 billion years ago.
