Question

In the lag phase, the growth is
A.Slowest
B.Fastest
C.Intermediate
D.No growth at all

Answer 1

Hint:Bacteria need specific conditions for their growth, and these criteria are not the same for all the bacteria. Factors like pH, oxygen, light, temperature influence the growth of the bacteria. The generation time of bacteria means the time taken by the bacteria to double its population.

Complete answer:Lag phase- This is the initial phase where there is cellular activity but no growth. A small amount of the bacterial colony is put into the nutrient-rich media which allows them to synthesize all the necessary proteins and molecules which is required during replication. In this stage, the cells will increase in size but with no cell division.
Log phase- Once the lag phase is completed the cell enters the log phase or exponential phase. During this phase, the cells are dividing through binary fission and are doubling in numbers after each generation time. Metabolic activity is very high. At this phase disinfectants and antibiotics are more effective because it targets the cell wall of the bacteria or the protein synthesis or RNA translation process.
Stationary phase- After the cell has undergone the log phase it then enters the stationary phase and the cell growth begins to decline because the nutrients in the medium will decline and the waste products start to accumulate. In the graph, this phase is seen as a plateau because the number of dividing cell is equal to the dying cell
Death phase- After the stationary phase, the cell comes to the death phase because the nutrients are depleted and the accumulation of waste products is more. The number of dying cells is more than the dividing cell. In this phase, the number of dying cells is declining gradually and comes to halt in the last.
Hence the correct answer is option D, with no growth at all.

Note: we can summarise the cell growth in four stages. The lag phase is the first phase where the cells will synthesize all the elements which are required for division. In the log phase, the cells will multiply exponentially and divide by binary fission. In the stationary phase, the number of dividing cells will be equal to the number of dying cells because of the depletion of nutrients. In the death phase, the number of dying cells is more than the dividing cells.