Viruses and Bacteria
It's easy to mix these up since compared to us, both are VERY SMALL.
But bacteria, given the proper nutrients, can grow and reproduce on their own. Viruses cannot "live" or reproduce without getting inside some living cell, whether it's a plant, animal, or bacteria.
And compared to viruses, bacteria are huge
The Virus that Infect Bacteria
T4 bacteriophage is a virus that looks like an alien landing pod.
With its six legs, the bacteriophage attaches to the surface of the much larger bacteria Escherichia coli (E. coli).
Once attached, the bacteriophage injects DNA into the bacterium. The DNA instructs the bacterium to produce masses of new viruses.
So many are produced, that the E. coli bursts.
Here's what an actual population of E. coli looks like as it is wiped out by T4 bacteriophage. You can also view this in an 800K time-lapse movie. For more on viruses that infect bacteria, visit the Bacteriophage Ecology Group and see their collection of phage images from around the Web.
Need a longer, larger, silent video of this clip for classroom use? It is available for immediate download as part of the "Bacteria Collection".
Here's what an actual population of E. coli looks like as it is wiped out by T4 bacteriophage. You can also view this in an 800K time-lapse movie. For more on viruses that infect bacteria, visit the Bacteriophage Ecology Group and see their collection of phage images from around the Web.
Need a longer, larger, silent video of this clip for classroom use? It is available for immediate download as part of the "Bacteria Collection".
Bacteria are all around us. Given good growing conditions, a bacterium grows slightly in size or length, a new cell wall grows through the center forming two daughter cells, each with the same genetic material as the parent cell. If the environment is optimum, the two daughter cells may divide into four in 20 minutes. Oh my! 1, 2, 4, 8, 16, 32, 64... Then why isn't the earth covered with bacteria?
The primary reason may be that conditions are rarely optimum. Scientists who study bacteria try to create the optimum environment in the lab: culture medium with the necessary energy source, nutrients, pH, and temperature, in which bacteria grow predictably.
المواضيع المتشابهه
Microbiology
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