- Life Sciences
a ring of muscle that controls the passage of substances through a tube or body opening.
the excessive growth of algae in eutrophic streams, rivers and dams.
dietary supplements of live bacteria that are good for human health.
a blind-ending lymphatic capillary found inside each villus for the absorption of the end...
tough cartilage that acts as a shock absorber between vertebrae and at the ends of bones in ball...