Approximately how many prokaryotic cells are typically found in 5 mL of fertile soil?

• A. 10^9 to 10^{10} cells
• B. 10^{12} to 10^{13} cells
• C. 10^5 to 10^6 cells
• D. 10^3 to 10^4 cells

Answer: (A)

Verified step by step guidance

1. Understand that fertile soil contains a very high density of prokaryotic cells, primarily bacteria and archaea, which are microscopic organisms abundant in soil environments.
2. Recall that typical estimates for prokaryotic cell counts in fertile soil range from about 10^9 to 10^{10} cells per gram of soil, reflecting the rich microbial diversity and biomass present.
3. Recognize that 1 mL of soil roughly corresponds to 1 gram of soil in terms of mass, so 5 mL of fertile soil would contain approximately 5 times the number of cells found in 1 gram.
4. Calculate the approximate range of prokaryotic cells in 5 mL of fertile soil by multiplying the cell count per gram by 5, which gives a range from 5 × 10^9 to 5 × 10^{10} cells.
5. Compare this calculated range to the answer choices provided to identify the range that best fits the typical prokaryotic cell count in 5 mL of fertile soil.