Question

Differentiate:
Coleorhiza & Coleoptile

Answer 1

Coleorhiza is a sheath protecting the root of a germinating grass or cereal grain. Coleoptile is a sheath protecting a young shoot tip in grass or cereal.

Complete answer: Coleorhiza and coleoptile are types of the sheath that emerge from monocot seeds, they occur in seeds before the seed germinates.
The difference between Coleorhiza and Coleoptile –

Coleorhiza	Coleoptile
Coleorhiza have undifferentiated sheath type	Coleoptile have protective sheath type
Coleorhiza has an undifferentiated sheath that encloses the radicle and protects the roots of the germination grass.	Coleoptile has a conical protective sheath which protects the young tip in grass enclosing plumule
Coleorhiza stays within the soil	Coleoptile emerges out of the soil turning it into green
Coleorhiza envelopes the root cap and radicle	Coleoptile envelops the plumule
Coleorhiza breaks through the seed coat and does not elongate further	Coleoptile breaks through the seed coat and elongates

Additional information: The coleorhiza is the first fragment to grow out of the seed. During germination, the coleorhiza grows through cell elongation but is eventually pierced through the root and then remains like a collar throughout the root base. The adventitious roots have a coleorhiza.
Coleoptiles contains very similar cells that are all specialized to fast stretch growth.
They do not differentiate but increase in size as they accumulate more water.
Coleoptiles have water vessels (frequently two) along the axis to give water supply.

Note: Both coleorhiza and coleoptile play a protective function. Coleorhiza is pale in color and does not contain chlorophyll whereas Coleorhiza is green in color due to the presence of chlorophyll and performs photosynthesis.