AP BIOLOGY

ANIMAL REPRODUCTION AND DEVELOPMENT

ASEXUAL REPRODUCTION

Please wait while the activity loads.
If this activity does not load, try refreshing your browser. Also, this page requires javascript. Please visit using a browser with javascript enabled.

If loading fails, click here to try again

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]

A certain strain of bacteria doubles every 20 minutes. If 2 bacterial cells are placed in a beaker with food. How many bacterial cells would you expect in 2 hours?

A	128
B	16
C	32
D	64

Explanation:

Detailed explanation-1: -Answer: 64 bacterial cells will be formed in 2 hours.

Detailed explanation-2: -If a bacterial cell is divided into 20 minutes, how many bacteria will be in 2 hours? If one cell divides into two in 20 minutes, then at the end of two hours, there will be 64 bacterial cells.

Detailed explanation-3: -One “trial” takes 20 minutes. So, after 3 hours, there have been: 60⋅320=9 trials. Therefore, there will be 29=512 bacteria.

Detailed explanation-4: -For example, Clostridium perfringens, one of the fastest-growing bacteria, has an optimum generation time of about 10 minutes; Escherichia coli can double every 20 minutes; and the slow-growing Mycobacterium tuberculosis has a generation time in the range of 12 to 16 hours.

There is 1 question to complete.