Biotic factors are the
living thing in an environment
non living things in an environment
soil in the environment
rocks in the environment

I believe the answer you are looking for is: Living thing in an environment  

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.

there really is life in the deepest part