Transcript 22.3 Seed Dispersal and Germination TEKS 10B

22.3 Seed Dispersal and Germination
The student is expected to:
10B describe the interactions
that occur among systems that
perform the functions of
transport, reproduction, and
response in plants
TEKS 10B
22.3 Seed Dispersal and Germination
TEKS 10B
KEY CONCEPT
Seeds disperse and begin to grow when conditions are
favorable.
22.3 Seed Dispersal and Germination
TEKS 10B
Animals, wind, and water can spread seeds.
• Seeds dispersed by animals can have nutritious fruits or
fruits that cling.
22.3 Seed Dispersal and Germination
TEKS 10B
• Seeds dispersed by wind can have wing- or parachutelike fruits.
Cypselae
Double samaras
22.3 Seed Dispersal and Germination
• Seeds dispersed by water can have fruits that float.
TEKS 10B
22.3 Seed Dispersal and Germination
TEKS 10B
Seeds begin to grow when environmental conditions are
favorable.
• Seed dormancy is a state in which the embryo has stopped
growing.
– Dormancy may end
when conditions are
favorable.
– While dormant,
embryo can withstand
extreme conditions.
22.3 Seed Dispersal and Germination
• Germination begins the growth of an embryo into a
seedling.
– water causes seed to swell and crack coat
– embryonic root, radicle, is first to emerge
– water activates enzymes that help send sugars to
embryo
TEKS 10B
22.3 Seed Dispersal and Germination
• Germination begins the growth of an embryo into a
seedling.
– water causes seed to swell and crack coat
– embryonic root, radicle, is first to emerge
– water activates enzymes that help send sugars to
embryo
– embryonic shoot, plumule, emerges next
TEKS 10B
22.3 Seed Dispersal and Germination
• Germination begins the growth of an embryo into a
seedling.
– water causes seed to swell and crack coat
– embryonic root, radicle, is first to emerge
– water activates enzymes that help send sugars to
embryo
– embryonic shoot, plumule, emerges next
– leaves emerge last
TEKS 10B
22.3 Seed Dispersal and Germination
TEKS 10B
• Once photosynthesis begins, the plant is called a seedling.