Flowers and Fruits

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Transcript Flowers and Fruits

Flowers and Fruits
Flower anatomy
Flower anatomy
• Sepals
– Green leaves that protect the flower before it
• Peduncle
– stem
Flower anatomy
• Petals
– Colorful leaf-like structures
– Attract animals and insects
• Calyx
– All sepals fused
Flower anatomy
• Male: Stamen
– Filament
• Stalk-like structure that hold up anther
– Anther
• Sack-like structure that holds pollen
– Pollen
• Contains
reproductive cells
Flower anatomy
• Female: Pistil
– Stigma
• Sticky part of pistil
• Receives pollen
– Style
• Rod that holds up
– Ovary
• Holds eggs
– Ovule
• Reproductive cell (eggs) that become seeds once
Types of Flowers
• Perfect flower
– Contains male and female parts
• Imperfect flower
– Contains only male or only female parts
• Complete flower
– Contain sepals, petals, pistil, and stamen
• Incomplete flower
– Missing either sepals, petals, pistil, or stamen
Imperfect flowers are always incomplete
Incomplete flowers are not always imperfect
Pollination and
• Sexual reproduction in plants
• Stamen releases pollen
• Pollen is carried to a stigma
– Does it have to be a different plant’s stigma?
– Can it be?
– How does it get there?
• Pollination occurs when the pollen reaches
a stigma
Pollination and
• Pollen moves down the style depositing
sperm into the ovary
• Fertilization occurs when that sperm
reaches an ovule inside the ovary
• Once fertilized eggs become seeds and the
ovary will swell and become fruit
Types of Fruits
• How can fruit be different?
• Name some different fruits
• What is the purpose of a fruit?
Types of Fruits
• It is the fertilized ovary of a plant that
grows to produce and protect seed.
• Once fertilization occurs, the flower is no
longer needed and dries up.
• Seed are formed within fruit.
• Fruit must be sufficiently mature for the
seed to be viable.
Types of Fruits
• Good fruit formation is essential for
farmers and other producers
– Why?
• The fruit that is often the most valuable
product of a plant
Types of Fruits
• Fleshy fruit
– Fibrous structure that surrounds the seed
– Pome
• Several seeds
– Drupe
• Single seed
Types of Fruits
• Dry fruit
– Formed in a pod or hull
– Caryopsis
• Thin wall
– Samara
• Wings attached
– Pod
• Definite seam
– Hull
• No seam
• Container of new life
• Good pollination is essential to creating
lots of new seeds
• What is their purpose?
– Reproduce plants
– Protect embryo
– Provide food for new plant to grow
• Human uses
– Food production
• Corn, soybeans, and wheat
– We want lots of seed from these plants
– Most valuable part of the plant
• Grapes, oranges, and watermelons
– We want few seeds from these plants
– The fruit without seeds is more valuable
• Seed structure
– External
• Protect and nourish internal parts
– Internal
• Embryo and food supply
• Monocots vs. Dicots
– Very similar
– Significant differences
• External
– Seed coat
• Hold seed together
• Protection
– Hilum
• Seed scar
• Attachment to fruit
– Micropyle
• Tiny opening
• Pollen entered
this opening
• Internal
– Cotyledons
• Fleshy parts that contain food
– Radicle
• Forms root
– Hypocotyl
• Connects cotyledons
to radicle
– Epicotyl
• Forms stem
– Plumule
• Above ground part
of plant
• External
– Seed coat
• Protects and shapes seed
– Seed scar
• Attachment point
– Silk scar
• Point that silk was
attached to ovule
• Internal
– Endosperm
• Stored food
– Radicle
• Forms root
– Hypocotyl
• Connects radicle
to food
– Epicotyl
• Forms stem
– Cotyledon
• Absorbs food and
moves it to cotyledon
– Plumule
• Develops leaves and stem