In most neurons the resting potential has a value of approximately-70mV
Answer: Possession of Valves
Explanation: Veins possess valves which ensures that blood flows in only one direction. Valves helps blood to flow back to the heart against gravitational force.
Arteries don't have valves because the pressure originating from the heart is capable of causing the blood to flow in one direction.
Because plants go through a cycle(the cycle is seed, seedling, plant, flower and tree.) and it takes time for the plant food, water, and nutrients to go though the plant.