Lichens have been described as "dual organisms<span>" because they are symbiotic associations between two (or sometimes more) entirely different types of microorganism - a fungus (termed the mycobiont) a green alga or a cyanobacterium (termed the photobiont).
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I believe a pot of water that is being heated by a electric burner. This is because the warmer water moves to the top and the cooler water moves down to the bottom of the pot. This causes a circular motion. The next example of convection heat is a hot air ballon rising and falling in the atmosphere. A radiator is also because the hot air is drawn out the top and the cooler air is drawn to the bottom.
The answer is B. Natural selection will find a way to affect one, then that one will affect many others.
