Changes in local environments can have global effects for several reasons. Animals, like birds, migrate from region to region. A change in one of their environments can cause behavioral changes which will affect other organisms living in these environments. Air and water move among regions.
Because they have the potential for regeneration of damaged cells
That xylem is the substances that feed the plant, the substances that go from the dirt to the plant's body; and the phloem is the substance that goes from the pant to the ground, it's like the excretion of the plant. It's like the xylem goes up and the phloem goes down. The xylem usually is composed by Na, K and other substances that need the plant to live.
