Microscope & Bacteria
Science Practicals: GCSE, topic 1.1.1
Microscopes
We can observe (see) structures within cells (sub-cellular structures) using microscopes.
Population of Bacteria
Bacteria multiply through simple cell division (binary fission), in which one cell divides to produce two cells. The average time for how often the bacteria divide is called the mean division time of that population.
Estimation
- A future population of bacteria can be estimated by multiplying the current population by two for every mean division time (time it takes for the bacteria to divide) that passes.
- Divisions can occur as frequently as once every 20 minutes in ideal conditions.
Test yourself on Microscope & Bacteria
Light Microscope
A strain of bacteria has a mean division time of 30 minutes. A group of 4 bacterial cells is left to grow. How many cells will there be at the end of 4 hours?
A colony of bacteria forms a circle with a diameter of 1.6cm. What is the area of the colony? (π = 3.141)
How do bacteria multiply?
Which of the following are true of the mean division time of a population of bacteria?