Question

What is etiolation?

Answer 1

Etiolation:

1. Plants that are grown in darkness exhibit a distinct morphology.
2. The details may vary from one species to another, but in a dicot such as a bean, the hypocotyl is elongated and spindly, with a pronounced plumular hook, or recurve, just below the first leaves.
3. The leaves themselves undergo limited development and remain small and clasping, as they were in the embryo.
4. Chlorophyll is absent and the seedlings appear white or yellow in color.
5. In monocot cereal grains the first internode, or mesocotyl, elongates excessively in the dark, and the coleoptile, which is a modified leaf, grows slowly. The primary leaves remain within the coleoptile and stay tightly rolled around their midvein.
6. This general condition exhibited by dark-grown seedlings is called etiolation.