10 most extreme places on Earth. A unicellular organism is any life form that consists of just a single cell. This group includes most life on Earth, with bacteria serving as the majority. The main groups of single celled life are bacteria, archaea (both prokaryotes), and the eukaryota (eukaryotes).
A hero (masculine) or heroine (feminine) is a person or main character of a literary work who, in the face of danger, combats adversity through impressive feats of ingenuity, bravery or strength, often sacrificing his or her own personal concerns for some greater good.
A protagonist (from Ancient Greek ÏÏÏÏÎ±Î³ÏÎ½Î¹ÏÏÎ®Ï (protagonistes), meaning 'player of the first part, chief actor') is the main character in any story, such as a literary work or drama. The protagonist is at the center of the story, typically makes the key decisions and experiences the consequences of those decisions.