Answer:
Xylem cells have no cytoplasm or end walls, meaning they form a tube through which water can pass freely to allow water transport. Lignin strengthens the cell walls, helping to support the plant.
Commensalism is the term you are looking for
Answer:
The intervertebral discs of the spinal column and 'long bones' such as the femur and tibia.
Explanation:
The word biology comes from the Greek word <em>bios</em>, meaning life, and <em>logos</em>, meaning study.
