Is there any explanation for fast rate of division of bacterial cells which prevents further growth of individual cells?
1 Answer
A unicellular organism's growth is limited, and it divides pretty soon.
Explanation:
The answer lies in the structure of bacteria.
Most bacteria are unicellular,sessile (fixed to a place, unable to move) organisms.
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The cell is bound by a membrane and a cell wall. The cell singlehandedly does all the work of living. A living membrane is rather fragile and beyond a size it would not be able to 'grow' without bursting at the seams. The physical limitations of surface area:volume ratio do not permit growth to larger dimensions.
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There are in bacteria no mechanical support systems: no rigid apparatus within or on the outside of the cell that would allow growth to exceed microscopic dimensions.
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Most significantly bacterial species have evolved such that they can colonize an immense variety of substratum and use the various substrata to survive. A small size helps in this.
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Bacteria are genetically equipped so as to make the best use of their small size. The bacterial cell can take in only a limited amount of nutrition, and divides at a faster rate when nutrient supply is abundant. So individual cells do not grow in size, rather the population grows in number.
(Bacteria however often get together to form * mats* * * and overcome the limitations of being single celled and microscopic.)
For a more advanced explanation
https://www.ncbi.nlm.nih.gov/pubmed/22575476
