How do Bacteria Divide? Flashcards
What is Binary Fission?
The process by which prokaryotic organisms, like bacteria, divide and reproduce.
It is NOT the same as mitosis or meiosis. These processes happen in eukaryotic cells.
What are the organelles of bacteria?
Cell Wall, Cytoplasm, Cell Membrane, Circular Chromosome of DNA (important genes), Plasmids (non-essential genes), and some have a flagellum.
What is the process of Binary Fission?
The process by which one bacterial cell divides into two.
Because bacteria are single-celled organisms, as well as being a type of cell division, binary fission is also a type of reproduction. This is because one organism has to split into two organisms. This can also be referred to as asexual reproduction.
Before a bacterial cell can divide, it needs to do 2 main things. What are they?
- Grow so it’s big enough to give rise to two new cells
- Replicate all of its genetic material so that there’s enough for each new cell. This means it has to replicate its circular chromosome of DNA and its plasmids.
Explain what happens after the bacterial cell grows and replicates its genetic material to preform binary fission.
**The circular chromosomes of DNA **move to either sides of the cell, so that the offspring cells will end up getting one each.
The plasmids are arranged randomly, so one offspring cells may end up getting more plasmids than the other.
Once it is ready to divide, it starts to grow a new cell wall down the middle of the cell. When it is complete, it allows the two halves to pull apart. Then it is complete, and we have two new bacterial cells.
‘A bacterial cell has a mean division time of 30 minutes. How many cells would it produce after 3 hours?’
Using this question as an example, how do you calculate the amount of bacterial cells that produce after a certain amount of time?
- Calculate how many division cycles there will be in 3h:
You can do this by dividing the total amount of time (3hrs/180mins) by the mean division time (30mins).
180 / 30 = 6
The bacteria would be able to undergo 6 rounds of division in the next 3h.
- Next, you need to figure out how many cells that would make:
We simply need to take our original cell (of which there is only 1), and multiply it by 2 or double it 6 times.
1 x 2 x 2 x 2 x 2 x 2 x 2 = 64
Therefore, there will be 64 cells after 3 hours.
