Are fat-soluble signal molecules that are derived from cholesterol.

Steroids

Explanation:

Signal molecules are produced by signalling cells and bind to the target cells to initiate a response. Steroids come under the category of small hydrophobic signalling molecules. They are lipids and hence fat soluble.

They are derived from cholesterol thus share the chemical structure with it. They have a hydrocarbon skeleton in the form of four fused rings. They can have different types of functional groups attached in different manner to the carbon skeleton. Example of steroid hormones are estradiol and testosterone.

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.

this transfer is call conjunction