Gymnosperms vs. Angiosperms

Exposed Seed Plants (Gymnosperms) vs. Flowering

Plants (Angiosperms)

• Gymnosperms – bear seeds directly on surfaces of cones (conifers such as pines and spruces)

• Angiosperms – bear seeds within a layer of protective tissue (grasses, trees, flowers)

Comparing Features of Seed PlantsComparing Features of Seed Plants

Feature

Seeds

Reproduction

Examples

Feature

Seeds

Reproduction

Examples

Gymnosperms Angiosperms

Bear their seeds on cones

Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination

Conifers, cycads, ginkgoes, gnetophytes

Bear their seeds within flowers

Can reproduce without water; male gametophytes are contained in pollen grains; fertilization occurs by pollination

Grasses, flowering trees and shrubs, wildflowers, cultivated flowers

Seeds• Seed plants can live just about anywhere due to the seeds• A seed is an embryo of a plant encased in a protective covering

surrounded by food• Seed coat protects embryo and prevents the seed from drying out

Seed coat

Embryo

Storedfood supply

Seed

Wing

A

B

Seed Dispersal

• Seed dispersal is varied– Some seeds stick to fur/hair/clothing– Some seeds have “wings” for “flying” in the wind or floating on

water– Other seeds are surrounded by fruit (ovary of the plant) to help

the seed to be eaten and ultimately dispersed somewhere else

Gymnosperm (“naked seed”)

• Reproduce with seeds that are exposed

• No flowers and are pollinated by wind or water

• Typically produce cones

• Include cycads (palm-like plants), ginkgo, conifers (pines, spruce, cedar trees)

Examples of Gymnosperms

Angiosperms (“enclosed seed”)

• Flowering plants – vast majority of plants reproduce with flowers

• Flowers attract pollinators that transport pollen from flower to flower– Colorful and fragrant flowers are pollinated by animals

• Flowers are reproductive organs that contain ovaries which surround and protect the seeds

• After pollination, the ovary develops into a fruit– Seeds inside the fruit are dispersed by the animals

that eat them

The Structure of a Flower

FilamentAnther

StigmaStyle

Ovary

Carpel

PetalSepal

Ovule

Stamen

Apple Fruit Development

Comparing Wind-pollinated and Animal-pollinated PlantsComparing Wind-pollinated and Animal-pollinated Plants

Characteristics

Pollination method

Relative efficiency of pollination method

Plant types

Reproductive organs

Adaptations that promote pollination

Characteristics

Pollination method

Relative efficiency of pollination method

Plant types

Reproductive organs

Adaptations that promote pollination

Wind-pollinatedPlants

Wind pollination

Less efficient

Mostly gymnosperms and some angiosperms

Cones

Pollination drop

Wind-pollinatedPlants

Wind pollination

Less efficient

Mostly gymnosperms and some angiosperms

Cones

Pollination drop

Animal-pollinated Plants

Vector pollination

More efficient

Angiosperms

Flowers

Bright colors, sweet nectar

Animal-pollinated Plants

Vector pollination

More efficient

Angiosperms

Flowers

Bright colors, sweet nectar

Diversity of Angiosperms

• Many different categories– Monocots and dicots– Woody and herbaceous– Annuals, biennials, and perennials

• Some categories can overlap

Monocots vs. Dicots

– Monocots - one seed leaf (cotyledon)• Parallel veins, flower parts in multiples of three,

fibrous roots

• Ex. Corn, wheat, lilies, orchids, palms

Monocots vs. Dicots (continued)

– Dicots – two seed leaves• Branched veins, flower parts in multiples of four or

five, taproot• Ex. Daisies, clover, oak trees, tomatoes, roses

Monocots vs. DicotsMonocots Dicots

Seeds

Leaves

Flowers

Stems

Roots

Single cotyledon

Parallel veins

Floral parts often in multiples of 3

Vascularbundlesscattered throughout stem

Fibrous roots

Two cotyledons

Branched veins

Floral parts often in multiplesof 4 or 5

Vascularbundlesarranged ina ring

Taproot

that

in

have

that

have

SeedGermination

Remains withthe seed

Emergeabove ground

Remainbelow ground

Monocots Dicots

1 Cotyledon 2 Cotyledons

Monocots vs. Dicots

Monocots vs. Dicots

Woody vs. Herbaceous

– Woody – strong stems like those of trees, shrubs, and vines

– Herbaceous – non-woody stems such as those of dandelions and sunflowers

Annuals, Biennials, and Perennials

– Annuals – complete their life cycle in one year (many summer garden plants)

– Biennials – complete their life cycle in two years (some summer garden plants)

– Perennials – live for more than two years (shrubs, trees, grass, etc.)