A seed contains an embryo plant and food stores. It protects the embryo with a seed coat until conditions allow germination. Germination begins when the seed absorbs water, causing the root and shoot to emerge from inside. There are two main types of germination - epigeal, where the shoot emerges above ground, and hypogeal, where it remains underground. Seeds come in many forms like fruits, vegetables, flowers and grains, and allow plants to disperse and regrow.

1. 1
SEED
what is a
seed
Parts of a
seed and
its’
purpose
Germination
process and
types
Types of
seeds
LEARNING FOCUS

2. SEED
 It’s a reproductive structure which disperses, and can survive for some
time.
 When a seed is exposed to proper conditions, water and oxygen are
taken in through the seed coat. The embryo's cells start to enlarge.
Then the seed coat breaks open and a root or radicle emerges first,
followed by the shoot or plumule that contains the leaves and stem.
 The warmer the environment, the faster the germination.
 Cases when proper conditions are not present, the seeds take longer
time to germinate.
 The seed coat protects the embryo until such time. Factors affecting
germination depends on moisture content, richness of soil,
temperature, light, fungi, insects etc.

3. Parts of a seed
 A seed contains a miniature
plant, called an embryo,
that can develop into a fully
grown plant.
 The outer shell of a seed,
called a seed coat,
protects the embryo.
 Inside the seed, a
nutritious material the
cotyledons provides food
to the embryo.
 The embryo has a baby
shoot and baby root.
A typical seed includes three
basic parts:
(1) an embryo,
(2) stored food
(3) a seed coat.

4. Types of seeds
 Fruit seeds – Mango, Papaya, Banana, Strawberries .
 Vegetable seeds – Beans, Okra, Beets, Tomatoes, Pumpkin.
 Flower seeds – Rose, Lily, Jasmine, Daffodils.
 Hybrid – When 2 variety of seeds are crossed for a 3rd
product. (artificial)
 Edible seeds – Grains (cereals, millets and legumes) Chia,
Hemp, Pumpkin, Legumes, Flax, Sunflower, Pine nuts, Poppy.
 Baby seeds - the type of seed that has been treated so that,
once it germinates, the plant remains small. (soft, tender and
sweet)
 Creole seeds - corn, beans, squash, melon, watermelon,
zucchini, and cucumber. (natural cross pollination)

5. Germination process
seed
Radicle,
root
Shoot
and plant
https://www.youtube.com
/watch?v=heU7J2580ug

6. Epigeal Germination Hypogeal Germination
 Epigeal germination is
when the germination of
a plant takes place
above the ground.
E.g., onion, beans,
cotton, castor.
 The cotyledons are
brought on the surface of
the soil along with the
shoot.
 Botanical term
indicating that the
germination of a plant
takes place below the
ground.
E.g. Mango, rice,
groundnuts, Maize.
 Cotyledons remain
below the soil surface.
Types of germination

7.  The hypocotyl has a
curved terminal part to
protect the plumule as it
comes out of the soil.
 The plumule comes out of
the seed by the elongation
of the hypocotyl.
 The energy for the growth
comes from the
cotyledons.
 The epicotyl has a
curved terminal part to
protect the plumule from
friction in soil particles.
 The plumule comes out
of the seed by the
elongation of the
epicotyl.
 The energy primarily
comes from the
endosperm.
Epigeal Germination Hypogeal Germination

8. Reflection time
 What is a seed?
 Name any three types of seeds?
 What is the use of a seed coat?
 Does germination take place when the soil is dry?
Explain.
 Explain hypogeal germination with examples.