The part of the root that contains transport tubes is the root hair. The primary role of the root hair is to absorb water and nutrients from the soil. They are hair-like and tubular in structure and are sometimes rarely visible by the naked eye.
Answer:
It is the second option. Lost as heat.
There are no natural predators of rabbits in Australia, so they are able to reproduce at an alarming rate unharmed. In the US however, there are foxes and other animals that prey on rabbits, which helps keep the rabbit population lower.