They all have different compositions of protons, neutrons, and electrons. This causes variety and makes atoms different so they can make up different substances
Answer: "To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells."
I think the organisms in that ecosystem would most likely have an problem in there ecosystem because if any animal adapted to that environment they would most likely be already adapted to that environment
I think it's oxygen and water because they are the substance for cellular respiration.
Mercury is a barren planet with little atmosphere. In many regards it is similar to our own moon. However, it is also very close to the Sun, so humans will have to set up bases in craters or near the Poles to avoid being blinded.
