Due to the force of the gravity the parts of the plant grows. This growth is called geotropism. There are two types of geotropism - negative geotroprism and postive geotroprism. Negative geotroprism means the upward growth and the downward growth is termed as postive geotroprism
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Geotropism is the response to gravity in which different parts of a plant grow in opposite directions like a root grows downwards whereas the stem grows upwards.
It's two states are :
  (1) POSITIVE GEOTROPISM (growing with gravity)
  (2) NEGATIVE GEOTROPISM (growing against gravity)
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