Seed Development & Sexual Reproduction

What are the 3 parts of a seed?

1. Embryo

2. Seed coat

3. Storage tissue

What are the 2 ways seeds are made?

1. Pollination: transfer of pollen from anther to stigma

2. Fertilization: fusion of male & female gametes inside embryo sac

What are the 2 types of pollination & their definitions?

Self: pollen & stigma from same genotype

Cross: pollen & stigma from separate flowers of two genotypes

What are the 2 methods of fertilization?

Meiosis: cross over Chromosomes get pieces exchanged

Mitosis: Replication

What are the 3 stages of seed development?

1. Embryo differentiation- divides into basal cell which anchors it to wall

2. Accumulation of food reserves- perisperm, cotyledons (during germination)

3. Maturation & Drying- decrease in water content, ABA plays crucial role

List 3 characteristics of a non-endospermic seed

1. Dominant embryo

2. Endosperm used up

3. Cotyledons primary storage

List 3 characteristics of an endospermic seed

1. Small embryo

2. Significant endosperm

3. Small cotyledons

List 2 characteristics of a vivipary seed

1. Seeds germinate w/o maturation & drying

2. Reduced ABA levels or sensitivity

List 3 characteristics of a Apoximis seed

1. Embryo by asexual means

2. Carbon copy clone from seed

3. Can make F1 hybrid

   1. Useful to rid clones of disease

Polyembyony

More than 1 embryo per seed