The answer is plants. Plants are at the start of the food chain :)
It is mass can not be created or destroyed
Answer:
https://www.biology-pages.info/T/Tropisms.html
Explanation:
This link holds all the information you need :D
Answer:
The force of surface tension in the lungs is so great that without something to reduce the surface tension, the airways would collapse after exhalation, making re-inflation during inhalation much more difficult and less effective. Collapse of the lungs is called alectasis.
Explanation:
That would be the independent variable :)