Seeds: Structure And Germination

This section covers the structure of seeds and the process of germination, highlighting the differences between monocot and dicot seeds.

Introduction

A seed is the mature ovule that contains an embryo, essential for the continuity of plant life and dispersal.

Structure Of A Seed

The section discusses the structural differences between monocotyledonous and dicotyledonous seeds, detailing their respective components.

Types Of Seeds

This section categorizes seeds into monocotyledonous and dicotyledonous types, highlighting their key features and examples.

Monocotyledonous (Monocot)

Monocot seeds are characterized by a single cotyledon and are an essential component of plant biology, illustrated through examples like maize.

Dicotyledonous (Dicot)

Dicotyledonous seeds contain two cotyledons and differ from monocots in several structural aspects.

General Parts Of A Dicot Seed

This section describes the essential parts of a dicot seed, such as the seed coat, hilum, micropyle, cotyledons, and embryo, emphasizing each part's function.

Seed Coat

The seed coat is the outer protective layer of a seed, consisting of two layers that help protect the embryo inside.

Hilum

The hilum is a scar on the seed coat marking the attachment point to the fruit, playing a crucial role in seed structure and functionality.

Micropyle

The micropyle is a small pore in the seed coat that facilitates water and oxygen entry during germination.

Cotyledons

Cotyledons are the seed's embryonic leaves crucial for nutrient storage and plant development.

Embryo

The embryo is the developing plant within the seed, crucial for the formation of a new plant post-germination.

Radicle

The radicle is the part of the seed embryo that develops into the root, playing a crucial role in anchoring the plant and absorbing nutrients and water.

Plumule

The section discusses the plumule, which is the part of the seed embryo that develops into the shoot of a new plant.

Structure Of A Monocot Seed

Monocot seeds, such as maize, have a unique structure featuring one cotyledon and specialized food storage tissues.

Single Cotyledon (Scutellum)

The scutellum is a key structure in monocot seeds, serving as the single cotyledon that aids in nutrient absorption and supports the embryo during germination.

Endosperm

The endosperm is a crucial part of the seed that provides nutritional support to the developing embryo.

Embryo

The embryo is a vital part of a seed, responsible for developing into a new plant.

Coleoptile

Coleoptile is a protective sheath that encases the plumule in a monocot seed, aiding its emergence during germination.

Coleorhiza

Coleorhiza is a protective sheath surrounding the radicle in monocot seeds, facilitating germination and growth into a new plant.

Types Of Seeds

Seeds are classified into monocotyledonous and dicotyledonous based on the number of cotyledons they possess.

Germination Of Seeds

Germination is the process by which seeds grow into seedlings under suitable conditions.

Types Of Germination

Germination involves two main types: epigeal and hypogeal, each characterized by the position of cotyledons during seedling development.

Epigeal Germination

Epigeal germination is the process where the cotyledons of a seed emerge above the soil as the plant grows.

Hypogeal Germination

Hypogeal germination is a process where cotyledons remain below the soil surface during seedling development.

Conditions Necessary For Germination

Germination requires specific conditions, including water, oxygen, suitable temperature, and viable seeds.

Changes During Germination

Germination involves crucial changes as seeds absorb water and convert food, leading to the growth of roots and shoots.

Significance Of Germination

Germination is crucial for the growth of new plants, allowing seeds to develop into independent organisms.