Factores abióticos de la selva Lacandona​

The higher you go up the less oxygen there is 

If the experiment was perfomed more then once and you get the same results

Atissue is a group of connected cells that have a similar function within an organism.

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on