Angiosperm Reproduction and Biotechnology

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5

Slide 33

Two common types of seed germination

(a) Common garden bean

Seed coat

Radicle

Hypocotyl

Hypocotyl

Cotyledon

Cotyledon

Cotyledon

Hypocotyl

Epicotyl

Foliage leaves

(b) Maize - corn

Radicle

Foliage leaves

Coleoptile

Coleoptile

Slide 34

Dicot: Common garden bean

Seed coat

Radicle

Hypocotyl

Cotyledon

Cotyledon

Hypocotyl

Epicotyl

Foliage leaves

Cotyledon

Hypocotyl

Slide 35

Monocot: Maize - Corn

Radicle

Foliage leaves

Coleoptile

Coleoptile

Slide 36

Fruit Form and Function

A fruit develops from the ovary.

It protects the enclosed seeds and aids in seed dispersal by wind or animals.

A fruit may be classified as dry, if the ovary dries out at maturity, or fleshy, if the ovary becomes thick, soft, and sweet at maturity.

Slide 37

Fruits are also classified by their development:

Simple, a single or several fused carpels.

Aggregate, a single flower with multiple separate carpels.

Multiple, a group of flowers called an inflorescence.

Slide 38

Developmental origin of fruits

Flower

Stamen

Carpels

Ovary

Stigma

Pea flower

Ovule

Seed

Carpel

(fruitlet)

Raspberry flower

Stigma

Ovary

Stamen

Stamen

Pineapple inflorescence

Apple flower

Stigma

Stamen

Ovule

Each segment

develops

from the

carpel

of one

flower

Pea fruit

Raspberry fruit

Pineapple fruit

Apple fruit

(a) Simple fruit

(b) Aggregate fruit

(c) Multiple fruit

(d) Accessory fruit

Sepal

Petal

Style

Ovary

(in receptacle)

Sepals

Seed

Receptacle

Remains of

stamens and styles

Slide 39

Fruit dispersal mechanisms include:

Water

Wind

Animals

Slide 40

Coconut

Dispersal by Water

Slide 41

Tumbleweed

Dispersal by Wind

Winged fruit of maple

Dandelion “parachute”

Winged seed

of Asian

climbing gourd

Slide 42