It is called a population since they are all the same species
There are 3 factors which are; temperature, pressure and concentration.
Answer:
This is a rather complicated thing to explain so I'll try my best. To put it in simple term the sun has whats called a SOI (sphere of infleunce) and anything inside of this is effected by the gravity of that planet or sun in this case. The earth is inside of this sphere of influence. The earth has a constant velocity that is making it move away from the sun but since it's in the suns SOI the path in which the earth moves is changed in a way that causes it to spin around the sun. The same thing is happening with the moon. I'm not 100% sure on this but I think the reason the moon does not just fly away towards the sun is because it is closer to earth and is more effected by earths SOI. Hope this cleared things up for you.
Etioliation means that you water plants that are planted in an area with little to no sunlight. This results in weak stems, smaller leaves, yellow color, etc. The seedlings that are grown in the dark are known as "skotomorphogenesis." Etiolation comes from something called "Auxin's" and Auxin's are moved from the top of the plant to the bottom which creates lateral buds. Typically, etiliation results in the chances being raised for the plant to receive sunlight but causes underiable symptoms.
Best of Luck!