keepgoing
Forum Fanatic
Topics: 115
Posts: 2,356
|
A bacterium, has lag phase of 40 min and generation time of 20min...how many cells will be there at the end of 120min,if there are 4000 cells to begin with and there is no stationary phase?
1.4 X 10(power 12)
2. 2.56 X 10(5)
3. 6.4 X 10(4)
4. 3.2 X 10(4)
5. 1.6 X 10(4)
___________________
God,be my strength.
|
| new_n_lost
Forum Hero
Topics: 724
Posts: 6,393
|
No Way I know this u will have to Explain me this.
___________________
"never argue with a fool, they'll bring you down to their level and beat you with experience" FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
|
| rock
Forum Elite
Topics: 23
Posts: 305
|
5-16000
|
| indidoc1
Forum Guru
Topics: 61
Posts: 1,159
|
3- 6.4* 10000
Edited by indidoc1 on 04/01/07 - 06:15 AM
___________________
"Whether you think you can or you think you can't, you're right!" ~ Henry Ford
|
| asherif
Forum Newbie
Topics: 0
Posts: 46
|
answer ==> 3. 6.4 X 10(4)
initial number of bacteria (4000)
we have 120 min
generation time (time which bacteria need to double)
after 40 mins (lag phase) bacteria will start multiplying (we still have 4000)
after 20 mins(60 mins from the begining) bacteria will be 8000
after 20 mins(80 mins) 16000
after 20 mins (100 mins) 32000
after 20 mins (120 mins) 64000
64000 = 6.4X10(4)
feel free to correct me if I'm wrong 
Edited by asherif on 04/01/07 - 07:33 AM
|
| keepgoing
Forum Fanatic
Topics: 115
Posts: 2,356
|
very well indi 
after 120 mintues,there would be 6.4 X 10(4)bacteria.As bacteria divides by BINARY FISSION there division would be like(considering no stationary phase)
TIME------------>Bacterial conc.
0---------------->4 X 10(3) ((((bcos we assumed 4000 cells to being with)
40(lag phase)--->4 X10(3)
60---------------->8 x 10(3)
80---------------->16 X 10(30 or 1.6 X 10(4)****ROCK it can not be b/c its juz 80 min and our target time is 120 min...
100--------------->32 X 10(3) or 3.2 X 10(4)
120--------------->64 X 10(3) or 6.4 X 10(4)
___________________
God,be my strength.
|
| keepgoing
Forum Fanatic
Topics: 115
Posts: 2,356
|
 ashrif good job!
___________________
God,be my strength.
|
| rock
Forum Elite
Topics: 23
Posts: 305
|
good question...learnt something today(everyday yu learn something new)....i actually thought that the bacteria after their first division will again go into the lag phase before starting to divide again and so i came to 16000 as the answer. well now i know the right thing
thanks keepgoing, i appreciate it...
|
| keepgoing
Forum Fanatic
Topics: 115
Posts: 2,356
|
rock
___________________
God,be my strength.
|
| lq2006
Forum Elite
Topics: 43
Posts: 382
|
3. 6.4 X 10(4)
|
| dncosta
Licensed, finally
Topics: 19
Posts: 603
|
6.4X10(4)
|
| unique1
Biochemistry
Topics: 23
Posts: 1,612
|
Good question and explanation . Thanks keepgoing.
Calculations are my nightmare 
___________________
I can't change the direction of the wind, but I can adjust my sails to always reach my destination.
|
| SmokyWaters
Forum Elite
Topics: 6
Posts: 447
|
6.4
|
| SmokyWaters
Forum Elite
Topics: 6
Posts: 447
|
6.4 ...easy way to calculate...
120-40 = 80
divide it by 20 which is the doubling time...gives 4 as answer
2 raised to the power 4 (doubling times) givs u 2 x 2 x 2 x 2 = 16 as the number of times it has multiplied...simple multiply 16 with the initial number
easy way for many (who re bad at maths) is to REMEMBER this
if
2 doubling times then just multiply the initial number by 4
3 doubling times then just multiply the initial number by 8
4 doubling times then just multiply the initial number by 16
5 doubling times then just multiply the initial number by 32
they arent goin to ask further ..m sure
|
|
| |
| | | | | | | | | | | | | | |
Similar forum topics