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?
Monocotyledon
Dicotyledon
Seed Coat
Cotyledon (x1)
Endosperm
Embryo
Epicotyl
Radicle
Seed Coat
Cotyledon (x2)
Endosperm
Embryo
Radicle
Hypocotyl
Epicotyl

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 thousand years.
Most seeds have a viable life of 3-15 years

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

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