Chapter 25 Plants Brandon Kraft, Carly Miller, and Nick Rego

Evolutionary Trends Among Plants Photoautotrophs-organisms that get energy from sun and CO 2 Photoautotrophs-organisms that get energy from sun and CO 2 Vascular plants Vascular plants Account for most plants Account for most plants Roots, stems, leaves Roots, stems, leaves Three Types Three Types Seedless Vascular Plants Seedless Vascular Plants Cycads, lycophytes, ferns Cycads, lycophytes, ferns Seed-Bearing Vascular Plants Seed-Bearing Vascular Plants Gymnosperms Gymnosperms Angiosperms Angiosperms Non-vascular plants Non-vascular plants Account for remainder of plants Bryophytes Liverworts Hornworts Mosses

Evolution of Roots, Stems, and Leaves Roots Roots Evolved for life on land Evolved for life on land Underground, absorbtive Underground, absorbtive Shoot systems Shoot systems Stems and leaves Stems and leaves Above Ground Above Ground Absorb Sunlight and CO 2 Absorb Sunlight and CO 2 Support of cell wall Support of cell wall Evolved Lignin Evolved Lignin Vascular tissue- for transport of materials Xylem Phloem Water conservation- necessary because of air exposure (prevents dehydration Cuticle Stomata

Evolution of Pollen and Seeds Heterospory Heterospory Produce two types of spores Produce two types of spores Sperm-bearing gametophytes Sperm-bearing gametophytes Female gametophytes Female gametophytes Spread by air, insects, birds Spread by air, insects, birds Seeds - contain embryo and sustinence Seeds - contain embryo and sustinence

Bryophytes Mosses(most common), liverworts, hornworts (nonvascular) Mosses(most common), liverworts, hornworts (nonvascular) 3 adaptive features: 3 adaptive features: 1. Above ground parts display a cuticle with numerous stomata 2. Cellular protective jacket surrounds the sperm-producing and egg-producing parts of the plant to prevent drying 3. The embryo sporophyte begins life inside the female gametophyte Branched, feathery patterns Branched, feathery patterns Reproduce w/ flagellated sperm, which require liquid water to reach and fertilize the eggs Reproduce w/ flagellated sperm, which require liquid water to reach and fertilize the eggs

Moss Life Cycle

Existing Seedless Vascular Plants Whisk ferns, Lycophytes, Horsetails, Ferns Whisk ferns, Lycophytes, Horsetails, Ferns 3 Differences from Bryophytes 3 Differences from Bryophytes Sporophyte not attached to a gametophyte Sporophyte not attached to a gametophyte Has vascular tissues Has vascular tissues Longer phase in life cycle Longer phase in life cycle Habitat Habitat Moist places Moist places Gametophytes lack vascular tissue Gametophytes lack vascular tissue Sperm needs water to reach egg Sperm needs water to reach egg

Life Cycle of a Fern

The Rise of the Seed-Bearing Plants *360 million years ago 3 differences from seedless vascular plants 3 differences from seedless vascular plants 1. Produce pollen grains-the sperm-bearing male gametophytes 1. Produce pollen grains-the sperm-bearing male gametophytes Microspores give rise to pollen grains Microspores give rise to pollen grains Does not depend on H 2 0 Does not depend on H Also produce megaspores, which develop inside ovules-at maturity is a seed (consist of female gametophyte) 2. Also produce megaspores, which develop inside ovules-at maturity is a seed (consist of female gametophyte) 3. Have H 2 0 conserving traits 3. Have H 2 0 conserving traits Thicker cuticles Thicker cuticles Stomata recessed below the leaf surface. Stomata recessed below the leaf surface.

Spore of A Lycophyte

Seed-Bearing Plants Depend on Depend on Pollen grains Pollen grains Ovules that mature into seeds Ovules that mature into seeds Tissue changes adapted to dry conditions Tissue changes adapted to dry conditions

Gymnosperms- Plants with “Naked” Seeds Have exposed seeds- gymnos means “naked,” sperma means “seed” Have exposed seeds- gymnos means “naked,” sperma means “seed” Conifers - have cones Conifers - have cones Woody trees/shrubs with needlelike leaves Woody trees/shrubs with needlelike leaves Cones- clusters of modified leaves that surround the spore-producing structures Cones- clusters of modified leaves that surround the spore-producing structures Firs, yews, spruces, junipers, larches, cypresses, etc. Firs, yews, spruces, junipers, larches, cypresses, etc.

Lesser Known Gymnosperms Cycads- have pollen-bearing and seed bearing cones that form on separate plants Cycads- have pollen-bearing and seed bearing cones that form on separate plants Tropical/Subtropical areas Tropical/Subtropical areas Largest seed-bearing cones Largest seed-bearing cones Many vulnerable to extinction Many vulnerable to extinction Gingko Gingko Gingko biloba - only survivor Gingko biloba - only survivor Diverse in dinosaur times Diverse in dinosaur times Males are resistant to insects, disease, and air pollutants Males are resistant to insects, disease, and air pollutants Gnetophytes- woody plants that have 3 types Gnetophytes- woody plants that have 3 types Tropics and arid areas **Groups of existing gymnosperms include conifers, cycads, ginkgos, and gnetophytes, which bear their seeds on exposed surfaces of cones and other spore- producing structures.

Conifers Gymnosperms that reproduce via Cone Structures (Pinecones) Gymnosperms that reproduce via Cone Structures (Pinecones) Conifers produce both male and female pinecones Conifers produce both male and female pinecones Male Pinecones Male Pinecones Produce Microspores (Pollen grains) that drift into the air Produce Microspores (Pollen grains) that drift into the air Female Pinecones Female Pinecones Produce Megaspores (Female Gametophtes) Produce Megaspores (Female Gametophtes) Accept Pollen grains Accept Pollen grains Pollen Grows into Ovule Pollen Grows into Ovule Fertilization Occurs months after pollination Fertilization Occurs months after pollination Slow Reproductive Rate Slow Reproductive Rate Disadvantage Angiosperms reproduce faster and compete for resources Deforestation Deforestation Vulnerable

Angiosperms The Flowering Seed-Bearing Plants Most Successful Plants Most Successful Plants Only plants that flower Only plants that flower Angeion- Female reproductive part of flower Angeion- Female reproductive part of flower Requires pollination Requires pollination Transfer of pollen from one plant to next Transfer of pollen from one plant to next Pollination Processes Pollination Processes Airborne pollen Airborne pollen Pollinators Pollinators Insects, bats, birds Insects, bats, birds Coevolution Coevolution Angiosperm diagram:

Dicots and Monocots Two Types Two Types Monocots and Dicots Monocots and Dicots Monocots Monocots Monocotyledon- Monocotyledon- One cotyledon (seed leaf for storage of food) in seeds One cotyledon (seed leaf for storage of food) in seeds Floral parts in groups of threes Floral parts in groups of threes Parallel veins in leaves Parallel veins in leaves Orchids, palms, lilies, grasses (most crops-wheat, corn, etc) Orchids, palms, lilies, grasses (most crops-wheat, corn, etc)

Dicots Dicotyledon- Dicotyledon- Two cotyledons in seeds Two cotyledons in seeds Floral parts in groups of four or five Floral parts in groups of four or five Net-veined leaves Net-veined leaves Most Herbaceous (non-wooden) plants Most Herbaceous (non-wooden) plants Most flowering shrubs and trees Most flowering shrubs and trees Water Lilies, Cacti Water Lilies, Cacti