The answer is; fossil
Fossil is defined as any dead organism ( or its trace or impression) of a past geological time that is naturally preserved in the earth in geological features such as rocks, bogs, and etcetera. Coral reef is no exception because it is considered a living organism. It is composed of colonies of coral polyps and algae that secrete a carbon carbonate skeleton.
Answer:
First, the activity that humans execute that affects their ecosystem positively is reforestation. Second, the activity that humans execute that affects their ecosystem positively is hunting. Their effects rely completely in nature, however, one improves the ecosystem by making it greener and increasing the space nature has to grow, while the other impacts the ecosystem negatively by unbalancing the food chain.
Explanation:
The reasons behind this answer are that in the first place the ecosystem is a very sensitive environment that can be affected by a wide range of factors. In the first place, reforestation helps the environment have better conditions for the animals that live in it, as well as to provide the human race a better quality of air, water and feel better after living in a more natural ecosystem. While hunting breaks the ecosystem's balance because it allows the food chain of the ecosystem to break and allow a general modification.
Diffusion is a spontaneous process in which molecules move with their concentration gradient. For example, if you place food coloring in water, the food coloring will slowly diffuse through the water until the entire solution has been balanced.
Osmosis is specifically the movement of <em>water</em> through a semipermeable membrane - meaning a membrane that can let some substances in but keep others out - and, similar to diffusion, it moves with its concentration gradient. For example, if you place a glucose solution sealed in plastic in water, water will move into the plastic to even out the concentration of glucose in the entire solution because glucose is too large to diffuse freely.
Hope this helped!
Not sure about the answer but I think its the size of the system