Answer:
Gravity.
Explanation:
Without air, living organisms would suffocate and die.
Without water, living organisms would dehydrate and die.
Without energy, living organisms would die instantly.
Without space, living organisms would be squished together and die.
The only logical answer left is gravity.
As in all animal cells<span>, the </span>cells<span> of the </span>human cheek<span> do not possess a </span>cell<span> wall. A </span>cell<span>membrane that is semi-permeable surrounds the cytoplasm. Unlike plant </span>cells<span>, the cytoplasm in an animal </span>cell is<span> denser, granular and occupies a larger space. The vacuole in an an animal </span>cell is<span> smaller in size, or absent.</span>
Life is a special thing. You have your time and when it is decided that you will pass on then you go to a special place un-known to our world. Sometimes it your death is accidental and sometimes it's because your time is up. But others have to accept when someone passes on because they should know, that there lived one is in great hands.
Planaria<span> can be </span>cut<span> into pieces, and each piece can </span>regenerate<span> into a complete organism. crazy huh</span>