In mutualism, both organisms benefit. In commensalism, one benefits and the other is unaffected; in parasitism, one benefits and the other is harmed. Some of these relationships are so close that we speak of the composite of two species as one unit; for example, we speak of the composite of algae and fungi as lichens.n commensalism, one benefits and the other is unaffected; in parasitism, one benefits and the other is harmed. Some of these relationships are so close that we speak of the composite of two species as one unit; for example, we speak of the composite of algae and fungi as lichens.
A meteoroid is a solid body in interplanetary space before it reaches the Earth's atmosphere. A meteor denotes the fiery streak or shooting star which appears when a tiny meteoroid strikes the Earth's atmosphere and burns up. Most meteors result from meteoroids no more than a few centimeters in diameter.
A meteor shower is when a number of meteors â or shooting stars â flash across the night sky, seemingly from the same point. Geminid Meteor Shower of 2012. Meteors are also known as shooting stars. They look like a streak of light shooting across the night sky.