In biology, the inner lining of tubular structures is called a lumen.
This can refer to numerous tubular structures in the body, such as the lumen of the veins and arteries, the lumen of the intestines or the tubes in the kidneys.
This term can also be used to describe a space defined by membranes of cell organelles such as the lumen of the mitochondria, the Golgi apparatus, and others.
Answer:
the role an organism plays in a community
the best organism for that would be grass because it collects water and sun energy and shares the energy with other organisms.
hope this helps you good luck.!!!!
Answer:
I believe it is Protein.
Explanation:
Hope my answer has helped you!
I think the parietal cells have canaliculi which secretes it
