Draw and Label a Standard Growth Curve

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Examlex · Accepted Answer

The Answer is Growth curve should have a flat lag phase,followed by an upward sloping log phase,then a flat stationary phase and lastly a downward sloping decline or death phase. The four phases are : 1)lag phase -the organisms are metabolically active but not increasing in number; 2)log phase -organism divides; 3)stationary phase -number of new cells produced equals number of cells dying; 4)decline phase -where many cells have lost their ability to divide.
Bacteria cannot increase exponentially forever as the amount of nutrients will always eventually be consumed/limited. Also toxic byproducts of metabolism would eventually build up.
One reason for the culture to increase again on day 4 is scavenging; in this case the dying cells release their cell components as nutrients that the remaining cells can use to grow. Another could be the production of spores. Or there could be a mutation that arises that allows the bacteria to grow on a new nutrient.

Draw and Label a Standard Growth Curve

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