I pretty sure that it include both biotic and abiotic. But "C" is wrong. Now your answers are between "A,B and C"
The process is called homeostasis.
Choices 1, 2, and 3 all emit carbon dioxide, not enough to destroy the planet, but they still can cause it over a large amount of time, due to Carbon Dioxide being a greenhouse gas. Therefore, the answer is 4. Bicycles do NOT emit any carbon dioxide at all.
I believe it is D. More African elephants today naturally lack tusks compared to the elephant populations 100 years ago, because big game hunters sought elephants for ivory.
Active transport is a cellular transport mechanism. It’s the movement of molecules that are assisted by enzymes along the way to a higher concentration.
