Describe the logistic growth model of the population along with a suitable curve. Why is this curve more realistic?
The logistic growth curve shows a sigmoid or an S-shaped curve. It has three phases:- i) Lag-phase:- It is considered to be an early phase showing little or no growth. The lag phase is one in which the under the population of cells adapt to or stabilize with the growth conditions before embarking on their multiplication. ii) Log phase or Exponential phase:- It is the middle phase of rapid or geometric rise. Once stabilized cells start to multiply rapidly when the small population is stabilized, the multiply becomes faster because of the plenty of food & other requirements of life. iii) Stationary phase or steady phase:- Soon after the number of food decreases in proportion to the number of cells & this results in the onset of the stationary phase. So in this phase, the number of new cells formed becomes approximately equal to the number of cells dead & thus there is no net increase in the number of cells.
