Answer:
Commensalism only occur among biotic factors
Explanation:
Abiotic factors are non-living factors that interacts with the biotic factor within an ecosystem. Commensalism is an association between two organisms in which one benefits and the other derives neither benefit nor harm.
From the above definition of commensalism, it is clear to note that it only involves two organisms rather than non-living organisms, hence; commensalism involves only biotic factors
"Scarus frenatus" I think
Red blood cells or white blood celss
The right answer is excess carbon dioxide.
For a cell to do a photosynthesis, it needs.
chloroplast
water (providing hydrogen and oxygen)
Carbon Dioxide (Providing Oxygen and Carbon)
And finally the sunlight.
This will produce, oxygen and glucose, two essential elements in animal life.
