Answer:
An ecosystem is biotic, not abiotic.
Explanation:
First, an ecosystem is a biological community of interacting organisms and their physical environment. Second biotic factors are nonliving things whereas biotic factors are living things in an ecosystem you have your producers or plants which then will be consumed by the primary consumers. With the primary consumers feeding the next group of consumers and then the next and then after they die they fertilize the ground allowing the producers to grow as it completes the circle of life.
Most climate scientists agree the main cause of the current global warming trend is human expansion of the "greenhouse effect"1 — warming that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere block heat from escaping.
Based on this exert, I'd say Option C
Functions of cell surface Receptors .
most ligands responsible for cell-cell signaling ( including neurotransmitters, peptide, hormones, and growth factors) bind to receptors on the surface of their target cells.
