If the flow of energy in an arctic ecosystem goes through a simple food chain, perhaps involving humans, starts from seaweeds to fish to seals to polar bears, then which of the following could be true?

A. Polar bears can provide more food for humans than seals can.
B. The seaweed can potentially provide more food for humans than the seal meat can.
C. The total biomass of the seaweeds is lower than that of the seals.
D. Seal populations are larger than fish populations.
E. None of the above are true

this protocol provides a detailed procedure for co-immunoprecipitation (co-ip) to identify protein–protein interactions.

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.