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 person who, in the opinion of others, has special achievements, abilities, or personal qualities and is regarded as a role model or ideal: My older sister is my hero. Entrepreneurs are our modern heroes.