wat is meant by ?

Wood is an example for the material possessing the property of anisotropy .It means that physical properties such as refractive index are all direction dependent.

dude !
crt answer is iodine !!!!!!
r u rite bout defn ?on anitropy ?

got it
anitropy is property of crystalling solids
n iodine is ...solid crystall
!!

wood is anisotrophic

no i think all except iodine are amorphous
hence isotropic

refer this link
http://en.wikipedia.org/wiki/Anisotropy

wood is aniotropic