Oxygen is absorbed in the lungs and then transported to all body cells through the bloodstream.

Muscle cells contract and relax, facilitating the movement of body parts such as the chest during breathing.

Living phloem cells, such as sieve tubes, companion cells, and phloem parenchyma, are essential for maintaining the metabolic processes involved in the transport of food throughout the plant. This ensures efficient distribution of nutrients to support growth, development, and energy ...

Sieve tubes in phloem are tubular cells with perforated walls, allowing for the transport of food materials like sugars from the leaves to other parts of the plant.

Tracheids and vessels have thick walls and are often dead cells when mature, whereas xylem parenchyma functions in storing food, and xylem fibers primarily provide support to the plant.