Q.Identify A, B, C and D in the table given below: Terms | Part of the plant it represents Pericarp | 'A' 'B' | Cotyledon in seed of grass family Embryonal axis | 'C' 'D' | Remains of nucellus in a seed
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Start your 14-day free trial to unlock the full solution →The table identifies key parts of a seed: Pericarp is the fruit wall, Scutellum is the cotyledon in grasses, the Embryonal axis comprises the Plumule and Radicle, and Perisperm is the persistent nucellus.
Understanding the structure of a seed is fundamental to comprehending plant reproduction and development. A seed is essentially a fertilized ovule, containing an embryo, stored food, and a protective seed coat. The terms in the table refer to specific components or modifications of these parts, each playing a crucial role. Let's break down each one.
Pericarp (A)
After fertilization, the ovary of a flower develops into the fruit, and the ovules inside mature into seeds. The wall of the ovary transforms into the fruit wall, which is known as the pericarp. This pericarp can vary greatly in texture and thickness; it might be dry and thin, as in nuts, or thick and fleshy, as in mangoes or peaches. Its primary function is to protect the developing seed and aid in its dispersal.
Therefore, 'A' represents the Fruit wall.
'B' (Cotyledon in seed of grass family)
The embryo within a seed consists of an embryonal axis and one or two cotyledons. Cotyledons are embryonic leaves that store food or help in its absorption from the endosperm. In monocotyledonous plants, such as those belonging to the grass family (e.g., maize, wheat, rice), there is only one cotyledon. This single cotyledon has a specific name due to its shield-like shape and its position lateral to the embryonal axis.
In the grass family, the single cotyledon is called the scutellum. It is typically large and shield-shaped, playing a vital role in absorbing nourishment from the endosperm and transferring it to the developing embryo during germination.
Therefore, 'B' is the Scutellum.
Embryonal axis (C)
The embryonal axis is the central part of the embryo from which the future plant develops. It is essentially the structural backbone of the embryo, bearing the cotyledons and having distinct ends that give rise to the shoot and root systems.
The embryonal axis consists of:
- Plumule: This is the embryonic shoot, located at the upper end of the embryonal axis. It develops into the shoot system of the plant, including the stem and leaves.
- Radicle: This is the embryonic root, located at the lower end of the embryonal axis. It develops into the root system of the plant.
- Epicotyl: The portion of the embryonal axis above the level of cotyledons, which terminates in the plumule. …
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