What was Anton van Leeuwenhoek’s contribution in the development of cell theory? A. He built the first compound microscope. B. He was the first to observe live cells in a sample of pond water. C. He concluded that cells exist in liquids. D. He stated that all living things are made of cells.

B. He was the first to observe live cells in a sample of pond water.

Explanation:

He was a self taught man that created the first microscopes which allowed him and others to see tiny organisms.

The other answers are not correct as Hans made the first microscope, cells existing in liquids were not a critical part of micro biology, and it was Schlieden and Schwann who created the cell theory that stated that all living things were made of cells.

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.

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