Question

A bacterium divides every 35 minutes . If a culture containing ${10}^5$ cell per ml is grown for 175 minutes. What will be the cell concentration per ml after 175 mts _______________.

• A. $32\times {10}^5$ cells
• B. $5\times {10}^5$ cells
• C. $35\times {10}^5$ cells
• D. $175\times {10}^5$ cells

Answer 1

Answer: (A)

$32\times {10}^5$ cells

It is given that a bacterium divides every 35 minutes,

At 0 minutes, the culture contains ${10}^5$ cells/ml.

After 35 minutes, the culture will contain $2^1\times {10}^5$ cells / ml

similarly, after 175 minutes, that is after 5 generations, the no. of cells

$=2^5\times {10}^5$ cells/ml.

This is equal to $32\times {10}^5$ cell/ml

So, (A) is the correct answer.