In physical geography<span>, a </span>dune<span> is a </span>hill<span> of loose </span>sand<span> built by </span>wind<span> or the flow of water.</span><span> Dunes occur in different shapes and sizes, formed by interaction with the flow of air or water. Most kinds of dunes are longer on the windward side where the sand is pushed up the dune and have a shorter "slip face" in the lee of the wind. The valley or trough between dunes is called a </span>slack<span>. A "dune field" is an area covered by extensive sand dunes. Dunes occur, for example, in some </span>deserts<span> and along some coasts.</span>
Answer:
The Yellowstone nourishment web given shows that voles and mice subject to grasses and herbs. The badger rely upon the two voles and mice. This perception can be induced as that voles can keep up bigger populace when they exist with mice. This is on the grounds that the badgers prey both on mice and voles yet not the only one on voles. Thus, the mice can likewise keep up a steady populace on coexisting with voles as there is equivalent open door for mice and voles be implored up on by badgers. The badgers can keep up a steady populace when they rely upon the two mice and voles for their nourishment. In this manner, the alternatives a,b
In my science classes, it was called a producer and or a keystone species
Pulmonary surfactant is a mixture of lipids and proteins which is secreted into the alveolar space by epithelial type II cells. The main function of the surfactant is to lower the surface tension at the ir/liquid interface within the alveoli of the lung. In babies born prematurely, pulmonary surfactant may not be present in adequate amounts due to insufficient exocytosis in type II alveolar cells.
