What you are talking about is grafting. This can be done (and is done commercially), between closely related plants (normally at a genus or species level). The success of the graft is determined by the type of plant.
It is commonly done with fruit trees and rose plants, where the best characteristics of the fruit (or flower bearing) plant are added to the rootstock of another (related plant), which has a good, vigorous root system.
Natural grafts sometimes occur in nature, but normally on the same plant - this happens where two branches rub together in the wind, over time they fuse and form a permanent attachment.
Limb
The biologist might infer that at one point in history the animal's ancestors had this limb. But as time went by the ancestors used to limb less, therefore, shrinking the limb or completely getting rid of it.
Yes, if they crawl over a small plant, they can crush it. If they climb on a tree with a weak limb, they can break it. I'm not sure about their urine and feces, but it would either be fertilizer or kill plants.
A prosthetic limb or "prosthetic"
The grass and the tree are two different plants so cutting down one will not affect the other.
Yes, if the citrus plant is grafted the stock plant can sprout from below the graft, resulting in two different citrus species on the same plant
regeneration
Limb or Tree Limb Arm or division
limb
Extremity.
Limb
a limb
Limb
limb, bough, scion
Branch is one and bough is another.
Arm. Leg.
Yes