Flowers and Fruits

Flower anatomy

Flower anatomy

• Sepals– Green leaves that protect the flower before it

opens• Peduncle– stem

Flower anatomy

• Petals– Colorful leaf-like structures– Attract animals and insects

• Calyx– All sepals fused

together

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

stigma

– Ovary• Holds eggs

– Ovule• Reproductive cell (eggs) that become seeds once

fertilized

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 incompleteIncomplete flowers are not always imperfect

Pollination and fertilization

• 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 fertilization

• 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

• Fleshy fruit– Fibrous structure that surrounds the seed– Pome• Several seeds

– Drupe• Single seed

Types of Fruits

Types of Fruits

• Dry fruit– Formed in a pod or hull– Caryopsis• Thin wall

– Samara• Wings attached

– Pod• Definite seam

– Hull• No seam

Seeds

• Container of new life

• Good pollination is essential to creating lots of new seeds

seeds

• What is their purpose?– Reproduce plants– Protect embryo– Provide food for new plant to grow

• Human uses– Food production

seeds

• 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

seeds

• Seed structure– External • Protect and nourish internal parts

– Internal• Embryo and food supply

• Monocots vs. Dicots– Very similar– Significant differences

Dicots

• External– Seed coat• Hold seed together• Protection

– Hilum • Seed scar• Attachment to fruit

– Micropyle • Tiny opening• Pollen entered

this opening

seeds

• Internal– Cotyledons

• Fleshy parts that contain food

– Radicle• Forms root

– Hypocotyl• Connects cotyledons

to radicle

– Epicotyl• Forms stem

– Plumule• Above ground part

of plant

monocot

• External– Seed coat• Protects and shapes seed

– Seed scar• Attachment point

– Silk scar• Point that silk was

attached to ovule

seeds

• 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