Plantae Seed Plants Vascular Plants Formation of vascular

Plantae Seed Plants

Vascular Plants • Formation of vascular tissue – Xylem (water) – Phloem (food) – True leaves, roots, and stems • Lignin • ______ generation dominate

Alternation of Generation

Alternation of Generation • Sporophyte dependent on gametophyte – mosses • Large sporophyte and small independent gametophyte – ferns • Gametophyte dependent on sporophyte – seed plants

Why be Sporophyte Dominant? • Reduced mutations – UV light harmful to DNA – Diploid (2 n) form copes better with mutations • two alleles

Why Retain Gametophyte Generation? • Ability to screen alleles – doesn’t require a large amount of energy • Sporophyte embryos rely on some gametophyte tissue

Seeds • A seed is a sporophyte in a package – spores are only single cells – packaged with food • All seed plants are _______ (more than one kind of spore) – megasporangia – microsporangia

From Ovule to Seed Develops from megaspore Whole structure Embryo, food supply, protective coat

Overview of Seed Plants • Produce Seeds – Can remain dormant for years – Pollination replaces swimming sperm • Gametophyte generation reduced – Gymnosperms lack antheridium – Angiosperms lack both archegonium and antheridium

Phylogeny

Gymnosperms (Naked Seed) • Division: Cycadophyta Ginkgophyta Gnetophyta Coniferophyta

• • Ginkgophyta Ginkgo or Maidenhair Tree Characteristic leaves Only one species Only ______ are planted

Cycadophyta • Cycads • Palm-like plants – Sago Palms • Leaves in cluster at top of trunks • True _____

Gnetophyta • 3 Genera • Ephedra • Mormon Tea – ______ • raises heart rate • raises blood pressure

Coniferophyta

Coniferophyta • Pine tree is the sporophyte generation • Contains both male and female cones – Pollen (______) cones (low in tree) • produces pollen – Ovulate cones (high in tree) with scales • produces seeds

Pine Life Cycle • No Antheridium (microsporangia) produce pollen grain (4 cells) – 2 prothallial cells – 1 generative cell » produces 2 sperm – 1 tube cell – _____ for dispersal

Pine Life Cycle • Ovule in a ovulate cone – integument (seed coat) (2 n) – megasporangia or nucellus (nutrition) (2 n) – 4 ________ from female gametophyte (3 die) • develops into female gametophyte – archegonium with eggs (n)

Angiosperms

Angiosperm

Flower • Sepals • Petals • Receptacle (part of the stem) • Stamen – Anther – Filament • Carpel – Stigma – Style – Ovary with ovule

Angiosperm Life Cycle

Angiosperm Life Cycle • No Antheridium (microsporangia diploid) • produce pollen grain – 1 ______ cell » produces 2 sperm – 1 tube cell

Angiosperm Life Cycle • Ovule in Ovary – megasporangia – produces 4 megaspores (3 die) • remaining one develops into female gametophyte called the _______

Angiosperm Life Cycle • Embryo sac (Female Gametophyte) consists of: – 7 cells (eight nuclei) due to 3 mitotic divisions • 3 • 2 • 1 ______ polar nuclei (one cell) _____ egg

Angiosperm Life Cycle • Double fertilization – one sperm unites with egg – one sperm unites with polar nuclei • develops into endosperm (3 n) • Fruit and Seed development – ovule = seed – ovary = fruit

Angiosperm Life Cycle

Cross Pollination • Most flowers do not self-pollinate – stamen and carpal may develop at different times – stamen and carpal may be arranged in flower to avoid contact

Angiosperm Radiation • Begins the Cenozoic era (65 mya) • Most closely related to the Gnetophyta • _____ – the mutual influence of two species on each other – plants and animals (insects, birds, bats)

Pollination

Dispersal

The Global Impact • Transformed atmosphere – reduced carbon dioxide – cooled the earth • Nonrenewable/Renewable resource

Plant Structure And Growth

The Plant Body is Composed of Cells and Tissues • Tissue systems (Like Organs) –made up of tissues • Made up of cells

Plant Tissue Systems • __________ Øphotosynthesis Østorage Øsupport Vascular Tissue System • __________ Øconduction Øsupport Dermal Tissue System • __________ ØCovering

Dermal Tissue System • Epidermis – Single layer, tightly packed cells – Complex Tissue – Does different things in different areas (roots vs. leaves) – usually transparent – secretes cuticle Periderm • ______ – – replaces epidermis in woody plants – protection

Root System • ______ – Tap Root – Lateral Roots Shoot System • ______ – Stems • Nodes (leaves are attached) • Internodes – Leaves • blades • petioles – Buds Plant Systems • Terminal (apical) • Axillary

Plant Growth Meristematic • _______ Tissue – generates cells for new growth (like stem cells in animals) • apical meristems • lateral meristems

Apical Meristems • increases length called primary growth Protoderm –______ - gives rise to dermal tissue Ground Meristem –________gives rise to ground tissue –_______ - gives rise to vascular tissue

Lateral Meristems • increases girth called secondary growth –_________produces secondary xylem and secondary phloem Cork Cambium –_______produces cork (outer most layer of bark)

Pine Tree w/ 8 Cotyledons!

The Root System • Functions – anchor plant – absorb minerals, water and nutrients – store food • Systems – ______ - one large root with smaller lateral roots (dicots) Fibrous roots threadlike roots – ______(monocots)

Root Tissue • Protoderm - gives rise to the epidermis • Ground Meristem – Cortex (external to vascular tissue) • Procambium - gives rise to the Stele (the vascular tissue of a _______ root or stem) – xylem and phloem – may include pith (parenchyma cells surrounded by vascular tissue)

Dicot Root vs. Monocot Xylem (larger, in red) Endodermis Phloem (smaller, greenish) Pericycle – one layer IN from endoderm, gives rise to lateral roots “Pith” – central core of parenchyma cells surrounded by xylem and phloem

Modified Roots • Food Storage – carrots, sweet potatoes, yams • Water Storage – pumpkin family • Propagative Roots – cherries, pears • Pnematophores – mangroves • Aerial Roots – orchids • Buttress Roots – tropical trees • Haustoria – dodder

Shoot System

Stems (Primary Growth) • Protoderm - gives rise to the epidermis • Procambium - gives rise to the stele – xylem and phloem in vascular bundles • dicots - found in ring • monocots - scattered throughout – includes “pith” in dicots • Ground Meristem – Cortex

______ – stele (vascular tissue) divided into strands in stems and leaves Sclerenchyma cells Phloem Xylem

Dicot Stem Vs. Monocot (35. 16) Vascular Bundle Ground Tissue (Pith) (Cortex) How can you tell root from stem?

Stems (Secondary Growth) • Occurs to increase girth (thickness) – Vascular Cambium • produces secondary xylem and secondary phloem – Cork Cambium • produces cork and phelloderm (thin layer of parenchyma cells) • together these structures are called periderm (Cork Cambium, cork, phelloderm)

Secondary Growth Derivative Vascular cambium

Secondary Growth of a Stem

• Pith • Primary Xylem • Secondary Xylem (wood) • Vascular Cambium Periderm Secondary Growth of a Stem (Inside to Outside) • Secondary Phloem • Primary Phloem • Cortex • Phelloderm • Cork Cambium • Cork (outer layer of bark)

Older, inner layers of 2° Xylem – no longer transport water Younger, outer layers of 2° Xylem still function in transport All tissue outside vascular cambium Missing cortex and phelloderm!

______ (Early) growth occurs more quickly. Cells are large and thin walled and have less strength. Summerwood (Late) growth occurs more slowly. Cells are thicker, more dense, and stronger.

Modified Stems • _____ - horizontal stems above the ground (strawberries) • Rhizomes - horizontal stems below the ground (Irises) • Tubers - swollen areas of rhizomes or stolons (Potatoes) • Bulbs & Corms - vertical shoots under ground (onions, garlic w/ mod storage leaves) Cladophylls • _______ cactus pads

Leaf Structure

Leaves • Epidermis Stomata – _____ - openings on underside of leaf – Guard Cells - surround stomata – Cuticle - waxy coating excreted by epidermis • Mesophyll - middle of leaf Palisade Layer - photosynthesis – ______ – Spongy layer - gas exchange

Modified Leaves Tendrils • ______attachment • Bracts –modified leaves that surround a group of flowers • Spines protection • Storage Leaves - succulents

Uptake of Nutrients Hydroponic ________ cultures used to determine which chemical elements are essential. 17 essential elements needed by all plants

NEED TO KNOW THE CHART!!!

Soil • Develops from weathered rocks – Anchors plants – Provides water – Provides dissolved minerals

Soil Texture • Pertains to sizes of soil particles – includes the following: • sands (0. 02 - 2 mm) • silt (0. 002 - 0. 02 mm) • clay (less than 0. 002 mm) • Loams (40/40/20)

Control Systems in Plants

Plant Hormones • Coordinates growth • Coordinates development • Coordinates responses to environmental stimuli

Auxins • Stimulates stem elongation • Stimulates root growth • Stimulates differentiation and branching • Stimulates development of fruit • Stimulates apical dominance • Stimulates phototropism and gravitropism

Auxin Control • Auxin stimulates growth • Auxin block on right causes cells to elongate and the plant bends left • Auxin block on left causes cells to elongate the plant bends right

• • Acid Growth ______ Hypothesis Proton pump stimulated by auxin lower p. H of wall H+ activates Enzyme breaks hydrogen bonds in cellulose Wall takes up water and elongates

Auxin Others • Promotes secondary growth by stimulating vascular cambium and secondary xylem • Promotes adventitious root at the base of a cut stem • Promotes fruit growth without pollination (seedless tomatoes)

Cytokinins • Works with Auxin: – more cytokinin - shoot buds develop – more auxin - roots develop • Stimulates germination • Delays Senescence

Gibberellins • Promotes seed and bud germination • Promotes stem elongation • Promotes leaf growth • Stimulates flowering and fruits – (with auxin)

Ethylene • Promotes fruit ripening • Controls Abscission (causes leaf loss)

Phytochromes • Function as photoreceptors / red (660 nm) to far red (730 nm) • Activates kinases (regulatory proteins)

Red vs. Far Red Response

Why plants are important? • Food! • Humans have domesticated plants for 13, 000 years. • ____ of all the calories consumed by humans come from six crops: Wheat, Rice, Maize, Potatoes, Cassava, and Sweet Potatoes. • Also, we use plants to feed cattle, 5 -7 kg to produce 1 kg of beef.

Pyramid of Net Productivity

Plants remove CO 2

25% of all US • _____ Prescription Drugs contain one or more active ingredients from plants. • 50% ____ earth’s species will become extinct within the next 100 years (larger than the Permian or Cretaceous) • Only 5, 000 of 290, 000 species have been studied. • 3 -4 species per hour, 27, 000 per year!

Cinchona tree • Bark contains _____ • Grows in the Andes in peru • Used since the early 1600’s to treat malaria

Aspirin • • • Acetylsalicylic acid or ASA Dates back to 3000 B. C. Greek Physician Hippocrates prescribed it. trees • From Willow _______ and other Salicylate-rich plants (leaves and bark) • Scientists at Bayer began investigating acetylsalicylic acid as a less-irritating replacement for standard common salicylate medicines. By 1899, Bayer named it this Aspirin

Ecology

Hadley Cell

Hadley Cells

Biomes

Charles Darwin • Differential Reproductive Success Adaptation • 1859 Origin of Species. • Romanes – Neodarwinism & The Modern Synthesis (Genetics)

Evolution in the Lab

Allopatric Speciation

Sympatric Speciation

Hugo De Vries • Evening Primrose

Need to know to here now!