Kingdom Plantae

Chapters 22-25

What Plants Need to Survive

• •

• Minerals, gas exchange, and movement of materials

• alternation of generations—one generation produces spores and other produces gametes

•Plants evolved from ancestors of modernalgae

• When moved onto land had to evolve structures to acquire, transport, and conserve water.• Also had to be able to reproduce sexually

Floweringplants

Cone-bearingplants

Ferns andtheir relatives

Mosses andtheir relatives

Green algaeancestor

Flowers; SeedsEnclosed in Fruit

Seeds

Water-Conducting(Vascular) Tissue

Evolution of Plants

Floweringplants235,000 species

Cone-bearing plants760 species

Ferns andtheir relatives11,000 species

Mosses andtheir relatives15,600 species

Diversity of Plants

Nonvascular Plants/ Bryophytes • ex-mosses, hornworts, liverworts• rhizoids-present instead of true roots --anchor plants to ground AND absorb water and minerals from soil by osmosis---no transport system for moving water and minerals.• low-growing, found in moist and shaded areas• can tolerate harsh environments

Vascular Plants:

Ferns, Gymnosperms,

and Angiosperms1. specialized vascular tissues to

transport water, minerals, and nutrients—two

types • Phloem—conducts sugars away

from leaves and stems

• Xylem---transport water and minerals

from roots to other parts of plant

2. Leaf-structure that carries out most photosynthesis

-contains vascular tissue in the form of veins

3. cuticle-waxy protective covering on leaves and stems

--impermeable to water and gases required by plant

4. Stomata-openings in cuticle that allow for gas exchange and transpiration (evaporation of water)

5. Guard cells-border each stomate and control its size by expanding and contracting at proper times.

Guard Cells

Open Stomate Closed Stomate

6. Roots-organ that absorbs water and minerals from soil, transports them to stem, & anchors plant into ground.

• actively growing portion of root is coveredby a root cap• root hairs-increase the surface area for water and nutrient uptake

•Two main types of roots

Taproot-largecentral root

Fibrous roots-rootsall about the same size

7. Stem-structural support for upright growth and transport of materials

Types of stems1. Herbaceous-flexible, soft, usually green2. Woody-stiff, nongreen, contain layersof wood.

Seedless Vascular Plants• ex-ferns, horsetails, clubmosses•reproduce asexually by forming spores on underside of leaves --spores found in sporangia• Next phase, Sexual reproduction, requires water

--sperm swim to eggs• highly divided leaves called fronds

Seed Plants• Adaptations that allow plants to reproduce without water

1. Flowers or cones-gametes grow within these

2. Transfer of sperm by pollination3. Seeds that house embryo

• Seed-contains zygote/embryo, food supply (endosperm), and protective coat (seed coat) to prevent drying out

Seed coat

embryo

Food supply

Seeds Continued• Allow offspring of plants to be dispersed to new locations-by wind, water, animals

• dormant stage of plant life cycle

• germination-early growth stage of plant embryo--occurs when conditions are right for growth (moisture and temperature)

Pollen• contains the male gamete (sperm)

• pollination-pollen grain is carried to egg-by1. Wind 2. Water3. Animals

Gymnosperms• gymnos=naked sperma=seed• First group to have seeds

• most gymnosperms are conifers- seeds are produced in cones

-ex-cedar, cypress, pine, & spruce

• Needle-like leaves--shape is an adaptation to reduce

surface area over which water is lost to evaporation• female and male cones—most are wind pollinated where pollen is carried by wind from male cone to female cone• adapted to cold climates-thick cuticle• retain leaves year-round=evergreen

Angiosperms• Flowering plants

• seed found within fruit

• Flower-reproductive structure• brightly colored or heavily scented toattract pollinators that carry pollen from one flower to another

-more direct than wind pollination

Flower Parts

Sepals-modified leaves

-male flower part-Stamen

Filament

Pg. 612

Anther

Carpel-female flower part

Petal

ovule

ovary

stigmastyle

• Stamen-male • made of

1. Anther-pollen-containing sac2. Filament-stalk of stamen

• Pistil/Carpel-female• made of

1. Style-stalk of pistil2. Stigma-sticky tip of style3. Ovary-swollen lower portion

-ovules-inside ovary

•Fruit• made of ovary with thickened wallsthat contains one or more seeds andother flower parts • adaptation for seed dispersal

-when animals eat fruit and thendefecate, seeds are passed

-THIS IS THE REASON FRUITS EXIST • many vegetables are fruits

• Cotyledon-seed leaves of embryo• store food

Monocots 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

Section 22-5

Figure 22–25 Comparison ofMonocots and Dicots

Go to Section:

Plant adaptations• aquatic• carnivorous • halophytes• desert plants• epiphytes• chemical defenses

Uses ofPlants• food, medicine,wood, rubber, clothing, etc.

Pitcher plants

Sundew

Venus Fly trap

Carnivorous plants