modification Flashcards
What are the food reserves stored in endospermic dicots?
Endosperm
During germination, the cotyledons act as absorptive organs to take up food reserves.
What happens to food reserves in non-endospermic dicots?
Quickly re-mobilized into the developing cotyledon for storage
The mature seed lacks endosperm.
What is the function of the testa?
Seed coat
Protects the seed.
What is the aleuron?
Endosperm cell layer
Plays a role in the seed’s nutrition.
What is the plumula?
The embryonic shoot
Develops into the foliage leaves.
What is the radicula?
Embryonic root
First part of the seedling to emerge.
What is the hypocotyl?
The embryonic axis between the cotyledons and radicle
Elongates during germination.
Define epigeal germination.
Cotyledons emerge from the soil with the plumule
Hypocotyl elongates and forms a hook.
What occurs during hypogeal germination?
Cotyledons remain in the soil
Epicotyl elongates to push the plumule out.
What is the overall process of seed germination?
The sum of events that begin with hydration of the seed and culminate in emergence of the radicle from the seed coat.
In epigeal germination, what happens to the hypocotyl?
It elongates and forms a hook
This hook straightens out upon exposure to light.
In hypogeal germination, how does the epicotyl behave?
It elongates to push the plumule out
The plumule points downwards, protected from damage.
Fill in the blank: The _______ is the first part of the seedling to emerge.
radicle
True or False: In non-endospermic dicots, the mature seed contains endosperm.
False
The mature seed lacks endosperm.
List the main parts of a seed.
- Testa
- Aleuron
- Plumula
- Hypocotyl
- Radicula
- Cotyledons
