Question

Coleoptile and coleorhiza are the protective sheaths covering _______ and _______ respectively
A.plumule, epicotyl
B. Radicle, plumule
C. Plumule, radicle
D. Radicle, hypocotyl

Answer 1

Hint: The epicotyl bearing shoot apex and leaf primordia are enclosed in a foliar structure, this is known as coleoptile. It preserves or protects the plumule during emergence from the soil whereas the radicle is protected in a sheath called coleorhiza during its passage into the soil.

Complete answer:
Plumule-
In-plant development during the emergence of the seedling, the young shoot, or plumule, is said to be negatively geotropic. This is because it moves away from the soil and rises by the extension of either the hypocotyl which is the region between the radicle and the cotyledons, or the epicotyl which is the segment above the level of the cotyledons.

Epicotyl-
In-plant physiology, the epicotyl refers to the embryonic shoot above the cotyledons. In most plants, the epicotyl will ultimately develop into the leaves of the plant. In dicots, the hypocotyl appears to be the base stem under the spent withered cotyledons, and the shoot just above that is the epicotyl.

Radicle-
In botany, the radicle is the first part of a seedling. It emerges from the seed during the process of germination. The radicle is the embryonic root of the plant, which grows downward in the soil. Above the radicle is the embryonic stem or hypocotyl which supports the cotyledon.

Hypocotyl-
The hypocotyl is the stem of a germinating seedling. It is found below the cotyledons (seed leaves) and above the radicle (root).

So, the correct answer is option B- " radicle, plumule"

Note: Coleoptile and coleorhiza are two structures of monocot plants. In-plant anatomy, the coleoptile, and the coleorhiza are known to play a protective function in the monocot seed and the characteristic features of both the structures differ with each other.