Active transport. it's the only method of transfer of material that is again concentration gradient
I would say A, B D are the correct answers
Answer:
All organisms that have life, both plants and animals.
Explanation:
You didn't provide an illustration, but I guess I can still help. Biotic factor means that it has life, abiotic means it's not alive (hence the a- at the beginning.) Some biotic factors of a pond ecosystem include: earthworms, fishes, frogs, plants and insects.
