BIOLOGY QUIZTest Your Knowledge Of Biology With These QuizzesBiology Online Quiz for Kids and Adults #1. How Many insects Are There on Earth? Ten billion Ten trillion Ten million trillion 100 billion Work Harder#2. How many neurons are there in an average human brain? One billion 100 Trillion 100 billion 1000 million Work Harder Previous FinishResultsWell Done. You Are Roaring Like A LionKeep Working. Slow & Steady Wins The Race START NEW