SEED DEVELOPMENT AND GERMINATION

1.   After fertilization:
     ·    zygote undergoes mitotic divisions
     ·    to form the embryo.

 

 2.   Endosperm muclei:
     ·    undergo mitotic divisions
     ·    to form endosperm tissue.

3.   Endospermic + embryonic development:

     ·    occur in the ovule.
     ·     integuments surrounding the ovule
     ·    will harden to form seed coat.

 

 

4.   Ovary à will become the fruit.

5.   There are two types of seeds:

     ·    monocotyledon (seeds have one cotyledon)
     ·    dicotyledon (seeds have two cotyledons)

6.   Germination:

     ·    emergence of the radicle
     ·     thru seed coat.

7.   Water:

     ·    required for germination
     ·     enters the seed by imbibition.
     ·    initiate embryo to synthesise gibberelin.

8.      Gibberelin will:

     .    diffuse thru endosperm àinto aleurone layer.
     .    initiate production of hydrolytic enzymes.

2.      Hydrolytic enzymes will:

     .    enter endosperm
     .       catalyse conversion of compound (stored in endosperm).

3.      Products (especially glucose) will be:

     .       transferred to the embryo
     .    used for respiration + germination