If the dead cell’s DNA codes for a property they do not have, then they have gained this property. Other nearby bacterial cells can absorb this DNA and add it to their own – and in this way they gain extra DNA. This includes the DNA, which may be complete or broken into bits. When one bacterial cell dies and its cell wall is ruptured, the contents are released into the environment. Some methods of DNA transfer between cells seem almost accidental. Bacteria are not quite the same as the higher animals, but they do transfer DNA from one individual to another… and they can have a sort of sex. Sexual reproduction – like that used by most animals and plants – involves at lease two individuals and normally these are called males and females. With this sort of reproduction you can start a population with just one bacterium. Then the two copies separate in the cell and the cell grows two new cell membranes (and two new cell walls) through its middle – effectively cutting the cell in half, to make two cells.īinary fission is asexual (the ‘a’ in front meaning without) reproduction, because both the daughter cells have exactly the same DNA as the original cell and only one cell is involved. First, the DNA in the cell makes a copy of itself. There is a little more to it than that though. The simplest form of bacterial reproduction is called binary fission.īasically, binary fission is where a bacterium grows to about twice the size of the smallest bacterium and splits in two. Still, it is worth remembering how quickly one bacteria can become many when it finds something it likes to eat. Which is why we aren’t swimming around in that soup of bacteria. In extreme conditions where there is very little food, or low temperatures it can take much longer still – which is good for us.Īlso, many things eat bacteria or cause them to die. In real life, a cell normally takes between 1 and 24 hours to reach maturity. But a mere three hours later, they would out weigh it 400 times.įortunately for us, bacteria never actually end up in a perfect soup. In 45 hours the bacteria would only weigh 78% of the weight of the earth. If this seems unbelievable, experiment with the maths. My old bacteriology teacher assures me that in 48 hours the total weight of all the bacterial offspring of just this one bacterium would weigh 400 times the weight of the planet earth! The numbers just keep doubling every twenty minutes and they get horrendously large. By the time you had morning coffee or recess at 10.40 am there would be 4.4 billion (that is 4.4 British Billions or 4.4 million million = 4,294,967,296 bacteria). If the first bacterium fell into a perfect soup at the stroke of midnight, there would be 2,097,152 of them by the time you woke up at 7.00 am. In another twenty minutes they become eight.
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