The sea was teeming with life. Eventually, through reproduction and continued variation, fish came about. There are over..
The gastrointestinal system breaks down particles of ingested food into molecular forms by enzymes through digestion and..
Geological periods is a study guide that cites the different geological periods on Earth's timeline. Each has a brief ov..
This tutorial looks at some of the communities in freshwater lentic habitats. For instance, symbiosis occurs in a commun..
Obtaining air outside an aquatic environment required species to acquire suitable adaptations, and this was the case of ..
The nervous system is essentially a biological information highway. This tutorial gives an overview of the nervous syste..