Wich type of symbios is each of these E. coli bacteria live in massive quantities in the large intestine of humans. They produce Vitamin K which aids in blood clotting.

Small spruce and fir trees grow in the shade of aspen trees in the forest. They would not grow as well in direct sunlight.

Bighorn sheep take in worm eggs when grazing. The worm egg hatches in the intestine and the larvae migrate to muscle tissue. When the larvae mature, they bore into capillaries and float to the lungs, where they form cysts. Large numbers of these can affect the breathing of the bighorn sheep.