The plant that is grownup in darkness exhibits a peculiar type of morphological features. The leaves of grass seedling will elongate but it curls towards the midvein. Only the coleoptile the modified leafs grows slowly whereas the internode, mesocotyl, grass seedlings elongates fast. Some other characteristics are low activity of the enzyme, absence of chlorophyll i.e. due to arrested chloroplast. These conditions which are shown by the dark-grown seedlings are called etiolation.