Biology · Sexual Reproduction in Flowering Plants · NEET
The plumule is above the cotyledons. The part of the embryonal axis above the level of the cotyledons is the epicotyl, and it ends in the plumule (the stem or shoot tip). Since the shoot grows upward, remember plumule sits on the upper side. This is the exact wording NEET uses, so learn 'above the cotyledons = epicotyl = plumule'.
Both are regions of the embryonal axis, split by the cotyledons. Epicotyl is the portion above the level of the cotyledons and ends in the plumule (shoot tip). Hypocotyl is the cylindrical portion below the level of the cotyledons and ends in the radicle (root tip). Simple key: epi- (upper) with plumule, hypo- (lower) with radicle.
The radicle forms the root when the seed germinates. The radicle is the root tip at the lower end of the hypocotyl and is covered by a root cap. The plumule forms the shoot. NEET 2024 gave a figure and asked which labelled part becomes the root on germination, and the answer was the radicle, so do not swap the two.
A dicot embryo has two cotyledons attached to the embryonal axis. The cotyledons store or absorb food and often become the first seed leaves. Between them runs the embryonal axis: epicotyl-plumule on the upper side and hypocotyl-radicle on the lower side. 'Di' means two, so two cotyledons is the defining feature of a dicot embryo.
No. Coleoptile and coleorhiza are found only in the monocot (grass) embryo. In a dicot, the plumule and radicle are not covered by these protective sheaths. If a question about a dicot mentions coleoptile, coleorhiza, or scutellum, that option is wrong. These belong to the monocot embryo, covered in the next concept.
Identify the part of the seed from a given labelled embryo figure which is destined to form the root when the seed germinates. (The figure shows a dicot embryo with parts labelled A, B, C and D; the lower tip below the cotyledons is labelled B.)
Try the real previous-year questions from this chapter — each with the answer and a full solution.
An embryonal axis and two cotyledons. The axis has the epicotyl ending in the plumule (above the cotyledons) and the hypocotyl ending in the radicle (below the cotyledons). The radicle also carries a root cap.
The plumule becomes the shoot and the radicle becomes the root. Plumule is at the top of the epicotyl; radicle is at the bottom of the hypocotyl with a root cap over it.
Because it has two (di) cotyledons. This is the key difference from a monocot embryo, which has only one cotyledon called the scutellum.
Yes. The radicle (root tip) at the lower end of the hypocotyl is covered by a root cap, exactly as NCERT states. This detail is often used to identify the radicle in labelled diagrams.
