Question

what is the meaning of tropism ?

Answer 1

Tropisms (Greek trope, turning) are responses of plants to directional stimuli (i.e. light, gravity). Photo- and gravitropism are mediated by growth hormone – auxin. Thigmotropism – growth in response to touch (enables roots to grow around rocks).

In virusology cell, tissue and organ specificities exhibited by viruses are called tropisms. A tropism by a specific virus usually reflects the presence of specific cell surface receptors on the eucaryotic host cell for that virus.