Page 15 - Chapter 14 Reproduction
P. 15
[ientify the parts 3f flower aril draw labelled diagram.
b: Examination of gram seed and maize grain
A seed develops from an ovule after fertilization. It consists of a protective seed
coat called testa, which varies from a thin membrane to tough covering. The testa is
enclosing an embryo which consists of a plumule (young shoot), a radicle (young
root) and one or two cotyledons (seed leaves). Seed has a tiny hole called micro-
pyle, which is the main site of water entry. The seed coat of gram seed is tough and
hard. In maize grain, cotyledon is modified into an organ called scutellum. In some
seeds, the cotyledon contains food reserves while in others a separate tissue called
endosperm is present for nourishment. Seeds of monocotyledonous plants have one
cotyledon while those of the dicotyledonous plants have two cotyledons.
Testa
Micropyle
Fig 14.10: Cram Seed (External and Internal) Structure
b: Examination of gram seed and maize grain
A seed develops from an ovule after fertilization. It consists of a protective seed
coat called testa, which varies from a thin membrane to tough covering. The testa is
enclosing an embryo which consists of a plumule (young shoot), a radicle (young
root) and one or two cotyledons (seed leaves). Seed has a tiny hole called micro-
pyle, which is the main site of water entry. The seed coat of gram seed is tough and
hard. In maize grain, cotyledon is modified into an organ called scutellum. In some
seeds, the cotyledon contains food reserves while in others a separate tissue called
endosperm is present for nourishment. Seeds of monocotyledonous plants have one
cotyledon while those of the dicotyledonous plants have two cotyledons.
Testa
Micropyle
Fig 14.10: Cram Seed (External and Internal) Structure
