Although dead leaves are no longer alive, they were considered as once part of a living entity. Therefore, dead leaves are biotic factors. Wind, iron gates, and sunlight are not biotic components because they are the non-living parts of the environment that influence biotic factors. Hope this helps.
Sumer has come up with a great analogy for a presentation she is giving in her psychology class. The membrane encasing a neuron only allows some ions to pass in and out of its channels. And she is going to describe this cell membrane as a guard only allowing some patrons to enter and leave a controlled area.