Ppt regarding Seed germination

1. WATCH IT GROW!!!
SEEDS AND
GERMINATION
Mahomet-Seymour High School

2. Would you Believe…
 A corn plant is bigger than a Redwood Tree?
 Wheat can live longer than an Oak Tree?

3. You Better Believe It…
CORN Redwood Tree
Wheat Oak Tree

4. Objectives…
 Define what a seed is and describe its
function.
 Discuss the parts of a seed and describe their
functions.
 Compare and contrast a monocotyledon and a
dicotyledon.
 Understand the general requirements of
germination.
 Discuss the steps in germination.

5. What is a seed?
 Seeds can be
thought of as
devices that protect
embryos until they
encounter
conditions that are
suitable for growth
as independent
plants.

6. What are the parts of a seed?
 Seed Coat: the outer protective layer of a
seed.
 Protects the seed from damage.
 Aids in Dormancy
 Cotyledon: part of the embryo of the seed.
 Generally becomes the first leaves of the plants
to emerge.
 Endosperm: tissue within the seed that act as
food for the undeveloped embryo.
 Embryo: contains all of the parts for the plant
to grow.

7. What are the parts of a seed?
 Radicle: the part of the embryo that emerges
to produce a temporary root system.
 Hypocotyl: the part of the embryo that breaks
through the soil and forms a small stem.
 Only present in dicotyledons.
 Epicotyl: the part of the embryo that emerges
from the soil to produce the first leaves.
 Hilum: present on pod seeds, this is the
attachment point of the seed to the pod.

8. What are the parts of a seed?
 Seed Coat
 Cotyledon (x1)
 Endosperm
 Embryo
 Epicotyl
 Radicle
 Seed Coat
 Cotyledon (x2)
 Endosperm
 Embryo
 Radicle
 Hypocotyl
 Epicotyl
Monocotyledon Dicotyledon

9. Monocotyledon Dicotyledon

10. 4 General Requirements for
Germination…
 Water: needed for imbibition.
 Causes seed to swell and embryo to grow.
 Oxygen: need for gas exchange.
 Available in soil pore
 Temperature: soil temperature needs to be at
an appropriate level for growth.
 Can vary between plants
 Light or Darkness: important for seeds that
germinate on top of the soil.

11. What is dormancy?
 Dormancy: a period of
non-growth.
 Seeds need to remain
dormant until the
conditions for growing
are right.
 Recently some seeds
were found viable
after 10-15 thousand
years.
 Most seeds have a
viable life of 3-15
years

12. What are the stages in
germination?
Monocotyledon
1. Seed swells (imbibition)
2. Radicle grows downward
3. Epicotyl grows upward
4. New leaves form and photosynthesis occurs
5. A new root system develops

13. What are the stages in
germination?
Dicotyledon
1. Seed swells (imbibition)
2. Radicle grows downward
3. Hypocotyl forms an arch (neck) and breaks
through the soil
4. Epicotyl receives light and photosynthesis
begins
5. New leaves form and the cotyledons fall off