Question
Biology Question on organisms and populations
The semilog of per minute growing bacteria is ploted against time. What will the shape of graph : -
A
Sigmoid
B
Hyperbolic
C
Ascending straight line
D
Descending straight line
Answer
Ascending straight line
Explanation
Solution
The growth curve for bacteria is hyperbolic. It shows various stages-lag phase, log phase or exponential phase, steady or stationary phase and decline phase. During lag phase there is very less growth of bacterial cells. In log phase, once the metabolic machinery is running they start multiplying exponentially, doubling in number every few minutes. In stationary phase, booming growth stops and number of bacteria stabilises. Last is death phase when the bacteria die due to lack of nutrients.