NEET Botany Biological Classification Questions Solved


A bacterium divides every 35 minutes. If a culture containing 105 cells/mL is grown for 175 minutes, what will be the cell concentration/mL after 175 minutes?

(1) 5 × 105 cells

(2) 35 × 105 cells

(3) 32 × 105 cells

(4) 4.175 × 105 cells

Audio Explanation:


(3) Total number of bacteria produced = 2n

n=Total timeTime of division=17535=5

Thus, after 5 divisions total number of bacteria will 25 = 32. Initially there are 105 bacteria/mL and therefore, after 175 minutes, the concentration of bacterial cell will be 32 × 105 or 3.2 × 106 cells/mL.

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