<P> Aquatic locomotion is biologically propelled motion through a liquid medium . The simplest propulsive systems are composed of cilia and flagella . Swimming has evolved a number of times in a range of organisms including arthropods , fish , molluscs , reptiles , birds , and mammals . </P>
<P> Aquatic locomotion is biologically propelled motion through a liquid medium . The simplest propulsive systems are composed of cilia and flagella . Swimming has evolved a number of times in a range of organisms including arthropods , fish , molluscs , reptiles , birds , and mammals . </P>
which are the two forces that are primarily responsible for propulsion in swimming
which are the two forces that are primarily responsible for propulsion in swimming
cilia flagella
cilia flagella