Answer:
A place where plants and animals interact with each other and the physical environment.
If too many plant eaters were alive there wouldn't be any more plants so other animals eat the plant eaters, but if there is too many animals to eat the animals that eat the plants there would be too many plants so there is another animal to balance it out.
Hope this helps.
Explanation:
I think it’s E (microtubules) i can be wrong but hopefully this helped
This is called bipedal locomotion.
The valves are responsible for preventing blood from flowing in the wrong direction, they are present in the veins, and the arteries don't need them because the aorta (biggest artery) pumps or in other words pushes it with such a force that no other force can change its direction, in the veins there is no structure present for pumping them as a result we have got valves so that they go in one direction...... the meaning of the word valve is to allow in one direction