An ecological niche is an organism's specific habitat in an ecosystem.
It is where it lives and feeds, etc.
Answer:
Thats WBCs cell which perform phagocytosis
Because some of them are immune and only works for one thing in the system
Well for starters, producers are living organisms that produce their own food. Like plants. And plants ironically provide us humans with oxygen as they live off of the carbon dioxide we produce. Some plants are also main vegetables that we eat, so put simply, a world without producers would be practically oxygen-less and vegetable-less.
