Kingdom Plantae

Outcomes Recognize the role of plants within an ecozone Use plant morphology to communicate about the role of plants in an ecosystem Understand how plants function including: photosynthesis, respiration, transpiration, function of root hairs, and vascular tissue

Kingdom Plantae All organisms on Earth depend on the photosynthetic ability of plants Autotrophs capture and store energy from sunlight in various compounds. Heterotrophs use the energy captured by autotrophs when they consume plants.

Sec 30-1 Overview of Plants Plants all share some characteristics All plants are photosynthetic. All plants are multicellular. All plants are eukaryotic organisms. All plants can reproduce sexually.

Adapting to Land Land plants had to develop new structures to replace the advantages provided by an aquatic environment. The earliest plants needed water to supply nutrients, for photosynthesis and for fertilization. In a terrestrial environment water may be scarce, most usable liquid water exists only in the soil. Temperature or climate on land is more unpredictable and harsher than in the water which means greater water loss by transpiration.

Preventing Water Loss One early adaption to life on land is the cuticle which enabled plants to conserve water by slowing evaporation from the plant’s body The cuticle is a waxy, waterproof layer that coats the parts of a plant exposed to air.

Preventing Water Loss Since the cuticle also did not allow CO2 into the leaf, small openings called stomata allows for the exchange of gases The stomata open and close depending upon the amount of water in the cells.

Plant Reproduction Early land plants needed water for reproduction, because sperm had to swim through water to fertilize an egg Successful land plants also developed structures that helped protect reproductive cells from drying out A spore contains a haploid reproductive cell surrounded by a hard outer wall. A seed is an embryo surrounded by a protective coat.

Seeds are more effective at dispersal than spores because: They are not as light so do not get lost as easily by the wind. They utilize wind and animals for dispersal They provide the offspring with food material known as endosperm.

Transport of Materials Early plants were short because they didn’t need much support and could not be far from their water source. An adaptation for support was development of lignin which is a hard compound that strengthens cell walls, enabling cells to support additional weight.

In addition to support was the development of special tissue for the transport of materials (water and nutrients) in the plant. This special tissue is called vascular tissue. There are two types of specialized tissue that makes up vascular tissue. Xylem – carries water and inorganic nutrients in one direction, from the roots to the stems and leaves. Phloem – carries organic compounds, in any direction, depending on the plant’s needs.

Classifying Plants The 12 divisions of plants can be divided into two groups based on the presence of vascular tissue. (Table 30-1) – p 4 The three divisions of nonvascular plants do not have true vascular tissue nor true roots, stems, or leaves. The nine divisions of vascular plants have vascular tissue and true roots, stems, and leaves.

Vascular Plant Classification Vascular plants can be divided into two groups Seedless Plants – the ferns and their relatives that reproduce by spores. Seed Plants – the plants that produce seeds for reproduction. Vascular Seedless Psilophyta Lycophyta Sphenophyta Pterophyta Vascular, Seed Gymnosperms Cycadophyta Ginkgophyta Coniferophyta Gnetophyta Angiosperms Anthophyta C - Monocotyledones C - Dicotyledones

Plant Evolution Scientists believe that plants evolved from multicellular terrestrial algae This is supported by the many structural and biochemical similarities: Both have the same photosynthetic pigments. Both have cell walls that contain cellulose Both develop a cell plate during cell division. Both store energy as starch.

Alternation of Generations All plants have a life cycle, called Alternation of Generations, that involves two phases The first phase consists of a haploid gametophyte that produces eggs and sperm. The second phase is a diploid sporophyte that produces spores.

Alternation of Generations The gametophyte produces structures that form gametes, egg and sperm, by mitosis. Once an egg is fertilized by a sperm and produces a zygote, the plant begins the second phase of its life cycle. The zygote divides by mitosis to form a sporophyte plant. The sporophyte produces structures that undergo meiosis to form haploid spores. These spores are released by most seedless plants, but are retained by seed plants. The life cycle begins again when the spores divided by mitosis to form new gametophytes

Alternation of Generations In nonvascular plants, the gametophyte is the dominant phase.

Alternation of Generations In vascular plants the sporophyte phase is the dominant phase.

Complete RG & Review 30.1

Sec 30-2 Nonvascular Plants The three phyla of nonvascular plants are collectively called BRYOPHYTES They lack vascular tissue and do not form true roots, stems, or leaves These plants usually live on land near streams and rivers.

Characteristics of Bryophytes Bryophytes are: Nonvascular Seedless Produce spores Usually very small plants (1-2 cm) Depend on water for reproduction Do not have true roots, stems or leaves

Bryophyte Structures Instead of roots, bryophytes have long, thin strands of cells called rhizoids that attach the plant to the soil. They have flat, broad tissues that function somewhat like leaves and are photosynthetic

Division Bryophyta - Mosses Thick carpet of moss on the forest floor Each gametophyte is attached to the soil by rhizoids Usually less than 3 cm tall

Division Bryophyta - Mosses The moss sporophyte is attached to and dependent on the large gametophyte

Division Bryophyta - Mosses Gametophytes maybe male or female

Division Bryophyta - Mosses

Division Bryophyta - Mosses Mosses are called pioneer plants because they are often the first to inhabit a barren area Mosses help prevent soil erosion by covering the soil surface and absorbing water

Division Hepatophyta - Liverworts Liverworts are unusual looking plant that grow in moist, shady areas They can have a thin transparent leaf-like structure on a stem axis They could have a thalloid form, a flat body that has an upper and lower surface.

Division Anthocerophyta - hornworts Hornworts grow in moist, shaded areas They share an unusual characteristic with algae, each cell usually has a single large chloroplast

Complete RG & Review 30.2

Sec 30-3 Vascular Plants Vascular plants contain specialized conducting tissue (xylem and phloem) that transport water and dissolved substance from part of the plant to another part of the plant.

Seedless Vascular Plants There are four phyla of seedless vascular plants Psilotophyta Lycophyta Sphenophyta Pterophyta

Division Psilotophyta – Whisk Fern Whisk ferns are not ferns at all. They have no roots or leaves and produce spores on the ends of short branches Whisk ferns are epiphytes, which means they grow on other plants but are not parasites

Division Lycophyta – Club Mosses Club mosses look like miniature pine tree, often called ground pines The cone-like structure, called a strobilus contains sporangia-bearing modified leaves

Division Spenophyta - Horsetails Horsetails have jointed photosynthetic stems that contain silica, with scale-like leaves at each joint

Division Pterophyta - Ferns Ferns have leaves (called fronds) and an underground stem (called a rhizome) New leaves of a fern are called fiddleheads.

Fern Life Cycle

Vascular Seed Plants The mobile sexual reproductive part of a seed plant is the multicellular seed. Plants with seeds have a greater chance of reproductive success than seedless plants.

Vascular Seed Plants Inside the tough, protective coat of a seed is an embryo and a nutrient supply When conditions favour growth, the see sprouts, or germinates, the embryo grows into a seedling

Vascular Seed Plants There are two main groups of seed-bearing plants Gymnosperms Angiosperms

Vascular Seed Plants - Gymnosperms Gymnosperms have ‘naked seeds’ – the seeds do not have a protective covering The largest division of gymnosperms are the conifers which produce cones

Vascular Seed Plants - Gymnosperms A cone is a specialized reproductive structure composed of hard scales, which produces seeds without a fruit. Most conifers have simple needlelike leaves

Vascular Seed Plants - Angiosperms Angiosperms produce seeds enclosed and protected by a fruit

Vascular Seed Plants - Angiosperms Angiosperms are referred to as flowering plants All angiosperms produce flowers and seeds The protective structure that contains the seed or seeds of an angiosperm is the fruit.

Vascular Seed Plants There are five phyla of vascular seed plants Cyadophyta Ginkgophyta Coniferophyta Gnetophyta Anthophyta

Vascular Seed Plants – Division Cycadophyta Cycads are gymnosperms, that flourished during the age of dinosaurs Most are native to the tropics and grow slowly Most cycads have fern-like, leathery leaves at the top of short, thick trunks

Vascular Seed Plants – Division Ginkgophyta Ginkgoes flourished during the time of the dinosaur Only one species survives today The ginkgo has fan-shaped leaves that fall from the tree at the end of each growing season so are called deciduous

Vascular Seed Plants – Division Coniferophyta The conifers are the most common Gymnosperms Conifers are woody plants and most have needles as leaves

Vascular Seed Plants – Division Coniferophyta A conifer usually bears both male and female cones. The male cones typically grow at the top of the tree while the female cone is below.

Vascular Seed Plants – Division Gnetophytes Gnetophytes are an odd group of cone-bearing Gymnosperms that have vascular systems that more closely resemble those of angiosperms

Vascular Seed Plants – Phylum Anthophyta (Angiosperms) The largest phylum of plants Known as flowering plants that produce seeds from flowers protected by fruit.

Vascular Seed Plants – Phylum Anthophyta A fruit is a ripened ovary that surrounds the seeds of angiosperms. The ovary is the female reproductive part of the flower that enclosed the egg.

Vascular Seed Plants – Phylum Anthophyta Angiosperms grow in many forms and occupy diverse habitats. Some are : Herbaceous plants with showy flowers or grasses Shrubs with flexible stems Vines with stems that will wind around objects Woody stems that have very solid stems

Vascular Seed Plants – Evolution of Angiosperms Angiosperms first appeared in the fossil record about 135 million years ago. Several factors led to the success of angiosperms: Seeds germinate and produce mature plants Fruits protect the seeds and aid in dispersal Have a more efficient vascular system Use animal and wind pollination More diverse, occupy more niches

Vascular Seed Plants – Phylum Anthophyta - Monocots and Dicots Angiosperms are divided into two classes: monocotyledones (monocots) and dicotyledones (dicots), by counting the number of seed leaves or coytledons, in the plants embryo

Vascular Seed Plants – Phylum Anthophyta - Monocotyledones Angiosperms with only one cotyledon are called monocots Typical monocot (corn and grass) has narrow leaves with parallel veins called parallel venation Flower parts are in multiples of three Vascular tissue bundles are scattered throughout the stem

Vascular Seed Plants – Phylum Anthophyta - Dicotyledones Angiosperms with two cotyledons are called dicots Typical dicot (beans and trees) have broad leaves with branching veins called net venation Flower parts are in multiples of four or five Vascular tissue bundles are arranged in rings in the stem

Vascular Seed Plant’s Success Neither gymnosperms nor angiosperms depend on an external source of water for fertilization. Fertilization occurs after pollen grains are transferred from one plant to another by wind or by animals The evolution of the seed and the decrease dependence on water have made the gymnosperm and angiosperm successful organisms

Activity – Plants around School In small groups, travel around the school to areas you may think there are plants (Mrs. Connors room, Mr. Rawlyk’s room), take a picture and then classify the plant based on what you observe, providing a justification for that classification. Major things to classify: - Take a picture! - Is it vascular or nonvascular? - Is it a seed-bearing Plant? - If so, is it an Angiosperm or Gymnosperm? - What division does it likely belong to? - If it’s an angiosperm, is it a monocot or dicot?