Transcript Seed Development and Germination Notesx

WARM UP
“A weed is but an unloved flower.”
–Ella Wheeler Wilcox
1. What does this mean to you?
2. How does this apply to plants and
reproduction?
Seed Development and
Germination
Ovules
• Ovule has an embryo, endosperm, and coverings
– Gets nutrients from plant
Seeds
• When coverings thicken and seal, food is
stored and seed is formed.
– Seed coat, endosperm, embryo
Seeds
• Cotyledons
– Part of the embryo that absorbs nutrients from
endosperm so growth can occur
Fruit
• Ovary ripens as ovule develops
• Eventually, fruit surrounds seeds
• Dry Fruits
– Legume
• Has a seam
• Peanut
– Achene
• Many fruits
attached to
large “wall”
• Sunflower
and
strawberries
– Nut
• Very hard
covering
– Samara
• Wing-like
structure
– Caryopsis
• Fruits/seeds
fused to wall
Fruit Types
• Fleshy Fruits
– Drupe
• Large pit in center
• Plum
– Hesperidium
• Thick rind, sections
• Lemons, limes
– Pepo
• Thin rind
• Cucumber, cantaloupe
– Pome
• Flower petals form skin
• Apple
– Aggregate
• Many ovaries in a single
flower make multiple
fruit sections
• Blackberries
– Multiple
• Many separate flowers
make separate fruit
sections
• Pineapple
Fruit Types
Germination
• Seeds take in water, swell, and rupture
– Seed coat broken by scratching, freezing, fire, etc.
• More oxygen, more cell division
• Primary root emerges 1st, then shoot
WRAP UP
• Name 3 “vegetables” that are
actually fruits.
• Name 3 vegetables that are truly
vegetables.