Athin extracellular layer upon which an epithelial rests is called"

Basement membrane

A thin extracellular layer upon which an epithelial rests is called a basement membrane.

Basement membrane is a specialised form of extracellular matrix on which a layer of epithelial cells rests . The basement membrane is made up of a mixture of collagens, and glycoproteins such as perlecan, heparan sulphate and entactin. The basement membrane supports the overlying epithelium by preventing any association between the epithelial cells and the other cells present within the tissue. The basement membrane also functions as a molecular filter as it permit only water and tiny molecules to move through.

step 1 ammonium can be absorbed by plants, but some is converted into nitrates which are better for plants to absorb. this is called nitrification. 2. step 2 the deer eats the plants and uses the nitrogen-containing proteins for cell growth. 3. step 3 bacteria in the soil conduct nitrogen fixation to convert nitrogen gas from the atmosphere into ammonium. 4. step 4 some of the nitrates are absorbed back into plants, but denitrification breaks down the nitrates into nitrogen gas released back into the atmosphere. 5. step 5 nitrogen is found in the urine, which gets broken down into ammonium through the process of ammonification. 6. step 6 plants absorb the ammonium and begin assimilation, the process to add the nitrogen to protein.

that scientist would be robert hooke