Only plants need cell walls, animals do not. Cell walls help maintain cell shape in plants, while the cell membrane helps support animal cells.
Explanation:
Pulmonary Arteries where the blood is re-oxygenated.
Decomposers eat dead consumers.
<span>Trophoblasts
Trophoblasts are cells that make up the external layer of a blastocyst, this is a major source of nutrient for a newly formed organism</span>
