Answer:
The original water sample contains 830,000 cells per milliliter.
Explanation:
A sample of well water is tested for its bacterial content in a plate count assay. A one-milliliter sample of the water is diluted in a 1:10 dilution series. One milliliter of the fourth dilution tube is plated in a pour plate. After incubation, the plate has 83 colonies, indicating that the original water sample contained 830,000 cells per milliliter.
<span>Too little is known about pre-Archean time, from the origin of Earth to 3.8 billion years ago, to divide that period into units.</span>
Bacteria
Explanation:
Nitrification fixation takes place by nitrogen-fixing bacteria like Azotobacter, Klebsiella, Bacillus etc which convert atmospheric nitrogen gas into fixed-nitrogen compounds like nitrates or ammonium ions for the plants to readily absorb.
The nitrogen fixing bacteria can be free-living like cyanobacteria or live with symbiotic relationship with plants and fungi.
The chemical conversion of di-nitrogen to ammonia takes place with the help of enzymes like nitrogenase in combination with leghahemoglobin, a protein through a reduction reaction.
The cell wall is a rigid organelle composed of cellulose and lying just outside the cell membrane. The cell wall gives the plant cell it's box-like shape. it also protects the cell. The cell wall contains pores which allow materials to pass to and from the cell membrane.
