Biology Today - February 2018

Structure of Dicotyledonous Seed

Structure of Monocotyledonous Seed

The monocotyledonous seeds possess a single cotyledon and are generally endospermic.

Papilla (remains of style)

Epithelial layer

Root cap Radicle

Embryonic leaves

Plumule

Aleurone region

It is a distinct layer that separates embryo from endosperm.

Seed coat

The seed coat is membranous and fused with the fruit wall.

Scutellum

A shield-shaped cotyledon.

Coleoptile

A sheath which covers the plumule.

Embryonal axis

It consists of plumule and radicle.

Coleorhiza

A sheath which covers the radicle.

Endosperm

It is the storage region which constitutes the bulk

of grain.

Fig : L.S of maize grain (seed)

Recalcitrant seeds are those seeds that get killed on reduction of moisture and exposure to low temperature, H.J., &RFRV, 7KHD and

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Orthodox seeds are those that can be stored for long as they can tolerate reduction in moisture content (upto 5%), exposure to anaerobic

conditions and low temperature H.J., legumes and cereals.

DESCRIPTION OF FLOWERING PLANT

• Various terms and terminologies discussed here are used to describe the plant so as to identify and place it within the
  appropriate taxonomic ranks. The various terms used are the habit, lifespan (annual, biennial, etc), habitat, type of roots and
  their modifications, stem and its types, leaves, their types and arrangements, venation, etc., inflorescence, characteristics of
  a flower and its different parts, types of fruit and seed.