Redbeds indicate the presence o iron in the environment. Red beds are red sedimentary rocks and the color is due to the presence of the ferric oxides. Ferric oxides occur as a coating on the sedimentary grains. In between the shale and cherts, iron-rich sediments can be found.
Body fluids are drawn into the valved ostia
These preparations are called Vaccines. A vaccine is a biological preparation that provides active acquired immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing micro-organism and is often made from weakened or killed forms of the microbe, its toxins or one of its surface proteins.
Organisms that eat they producers or that don't make their own food
D! Predictable and controlled
