Silica may not be a word you commonly hear associated with diet (or foods that prevent hair loss, for that matter). If youâre looking to promote hair growth and prevent hair loss, however, silica will need to be on your menu.
keystone-the central building block at the top of an arch or vault. headstone, key. arch - (architecture) a masonry construction (usually curved) for spanning an opening and supporting the weight above it. building block-a block of material used in construction work.
It is now known that all different types of species can be considered keystone. Anything from plants to microorganisms can have the important role of keystone species in different ecosystems. Examples of Keystone Species. One example of a keystone species is the prairie dog. They dig tunnels that form prairie dog towns, which can be hundreds of acres in size. The towns help the prairie by providing homes for animals like black-footed ferrets, burrowing owls, and snakes.