Evolution of Plants Chapter 16 Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Adapting to Terrestrial Life Vascular Plants Seedless Vascular Plants Outline Adapting to Terrestrial Life Vascular Plants Seedless Vascular Plants Seed Plants Gymnosperms Angiosperms Flowers Dicots and Monocots Seed Dispersal Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Adapting to Terrestrial Living Green algae that were probably the ancestors of today’s plants are aquatic organisms not well-adapted to living on land. Had to overcome three challenges: Minerals absorption from rocky surfaces Water conservation Reproduction on land Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Adapting to Terrestrial Living Mineral Absorption Plants require relatively large amounts of six inorganic minerals: Nitrogen, potassium, calcium, phosphorus, magnesium, and sulfur. Mycorrhizae Water Conservation Cuticle - watertight outer covering. Stomata - gas and vapor exchange. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Adapting to Terrestrial Living Reproduction on Land Due to immobility, gametes must avoid drying while they are transferred by wind or insects. Spore Development Generation alteration Sporophytes - diploid generation Gametophyte - hapolid generation Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Generalized Plant Life Cycle Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Evolution of Vascular System Terrestrial plants are required to carry water up from roots to leaves, and carbohydrates down from leaves to roots. Vascular System Specialized strands of connected hollow cells. Nine of Twelve living plant phyla are vascular. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Only two phyla of living plants lack a vascular system: Nonvascular Plants Only two phyla of living plants lack a vascular system: Liverworts (Hepaticophyta) Hornworts (Anthocerophyta) Simple Vascular Systems Mosses were first plants to evolve strands of specialized conduction cells. No specialized wall thickening. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Moss Life Cycle Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Evolution of Vascular Tissue Appeared approximately 430 mya. Grew by cell division at the tips of stem and roots (Primary Growth). About 380 mya vascular plants developed a growth in which a cylinder of cells beneath the bark divides, producing new cells around plant’s periphery (Secondary Growth). Necessary for tall trees with thick trunks. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Leaf Vascular System Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Seedless Vascular Plants Most abundant of the four phyla of seedless vascular plants contain ferns with about 12,000 living species. Have both gametophyte and sporophyte individuals, each independent and self-sufficient. Gametophyte produces eggs and sperm. Sporophyte bears and releases hapolid spores. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Fern Life Cycle Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Male and Female gametophytes Seed Plants Seed - Embryo cover that offers protection of embryonic plant at its most vulnerable stage. Male and Female gametophytes Male - microgametophytes (pollen grains) arise from microspores. Female - megametophytes contain eggs and develop from megaspores produced within ovule. Pollination - transfer of pollen. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Five living phyla of seed plants: Four are gymnosperms - ovules not completely enclosed by sporophyte tissue at time of pollination. Fifth is angiosperms - ovules completely enclosed by vessel of sporophyte tissue (carpel) at time of pollination. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Seed Structure Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Adaptive value of seeds: Dispersal Facilitate migration and dispersal Seed Plants Adaptive value of seeds: Dispersal Facilitate migration and dispersal Dormancy Wait for favorable conditions Germination Synchronization with environment Nourishment Energy source for young plants Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Coniferophyta (Conifers) Trees that produce seeds in cones. Gymnosperm Phyla Coniferophyta (Conifers) Trees that produce seeds in cones. Most familiar of four gymnosperm phyla. Seeds develop on scales within cones and are exposed at time of pollination. Cycadophyta (Cycads) Ginkgophyta (Ginkos) Gnetophyta (Gneetophytes) Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Conifer Life Cycle Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Comprise 90% of all living plants. Rise of Angiosperms Comprise 90% of all living plants. Use roots to anchor plants in one place to obtain nutrients. Produce tiny male gametes that are easily transported. Flower - reproductive organs that employ bright colors to attract pollinators and nectar to induce entrance into the flower to contact pollen grains. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Structure consists of four distinct whorls: Flowers Structure consists of four distinct whorls: Outermost - Protects flower from physical damage (sepals). Second - Attracts pollinators (petals). Third - Produces pollen grains (stamens and anther). Fourth - Produces Eggs (Carpel) Ovary Style Stigma Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Angiosperm Flower Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Why Different Kinds of Flowers Different pollinators are attracted to specific types of flowers. Bees most numerous insect pollinators. Becomes coated with pollen while inside the flower. Butterflies Moths Hummingbirds Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Male gametophyte contains two sperm. Double Fertilization Angiosperms produce a highly nutritious tissue (endosperm) within their seeds. Male gametophyte contains two sperm. Second fuses to form endosperm cell (double fertilization). Dicotyledons - Embryos with two seed leaves. Monocotyledons - Embryos with one seed leaf. Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Angiosperm Life Cycle Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Dicots and Monocots Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Seed Dispersal - Fruits Fruit - mature, ripened ovary containing fertilized seeds, surrounded by a carpel. Fleshy fruits encourage predation. Berries - Many seeded forms on inner carpel wall. (Grapes, Tomatoes) Drupes - Stony inner layer adhering to single seed. (Peaches, Olives) Pomes - Fleshy portion comes from petals and sepals. (Apples, Pears) Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Adapting to Terrestrial Life Vascular Plants Seedless Vascular Plants Review Adapting to Terrestrial Life Vascular Plants Seedless Vascular Plants Seed Plants Gymnosperms Angiosperms Flowers Dicots and Monocots Seed Dispersal Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies

Copyright © McGraw-Hill Companies Permission required for reproduction or display Johnson - The Living World: 3rd Ed. - All Rights Reserved - McGraw Hill Companies