Bacteria culture starts with 400 bacteria and grows at a rate proportional to its size. after 4 hours, there are 9000 bacteria. a. find an expression for the number of bacteria after tt hours. b. find the number of bacteria after 5 hours. c. after how many hours will the population reach 3

A)

B)

C) or hours

Explanation:

A) The formula that can be used for bacteria after "t" hours is

Where ,

represents the population after "t" hours

represents the initial population.

represents the rate of growth of population

represents the time taken by the population to grow

B) Here let us first find the rate of population growth.

Thus, the population of bacteria after 5 hours

C)

answer: - b cells

explanation: -

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.