Seed Plants Gymnosperms & Angiosperms 1
Quick Defs Vascular = xylem and phloem Xylem = Brings water/nutrients from roots to the plant. Phloem = Brings sugars down from the leaves 2
Evolution Of Land Plants REMEMBER: Terrestrial plants evolved from a green algal ancestor The earliest land plants were nonvascular, spore producers (bryophytes) Ferns were the 1st vascular, spore producing plants Gymnosperms & angiosperms were the 1st vascular, seed plants 3
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Characteristics of Seed Plants Multicellular Autotrophic Reproduce by Seeds Vascular tissue for transport Heterosporous make female megaspores & male microspores Dandelion dispersing seeds 5
Reasons for Success on Land Waxy cuticle Stomata with guard cells to open & close Seeds protect developing embryo & contain food 6
Seeds Seeds contain a young, developing plant embryo Seeds are covered with a protective seed coat (testa) 7
Seed Dispersal Seeds must be scattered (dispersed) away from the parent plant Testa (seed coats) may last thousands of years Seeds eaten by animals aren t digested but pass out with wastes 8
Seed Dispersal Seeds may have adaptations such as stickers, hooks, or fuzz to adhere to animals 9
Seed Dispersal Both water and wind can scatter seeds Wind Dispersal Water Dispersal 10
Seed Dispersal Methods 11
Gymnosperms and Angiosperms Gymnosperm Intro and evolution Life cycle and reproduction Uses and significance Angiosperms: Flowering plants Intro and evolution Life cycle and reproduction Uses and significance Monocots vs. dicots 12
GYMNOSPERMS Introduction Gymnosperm means naked seed (From the Greek: gymnos = naked; sperm = seed) More advanced than ferns do not have spores, they have seeds. The seeds of the gymnosperms lack a protective enclosure (unlike flowering plants which have flowers and fruit). Examples of gymnosperms: Conifers (pine trees), cycads, ginkgo biloba 13
Conifers Conifers adapted to temperate to cold regions Narrow leaves (needles) help to conserve water Covered by resins for protection from predators, fire, etc. 14
Other gymnosperms Cycads short shrubs, native to tropical regions (look like palms) Ginkgo biloba a living fossil, male and female tree, used as a medicinal plant 15
Significance of gymnosperms Ecological importance: Provide food and habitat for wildlife Forests prevent soil erosion Reduce greenhouse-effect gasses Economic and commercial importance: Lumber for wood, paper, etc. Resins wood, furniture, etc. Ornamental plants (trees, landscaping) Food pine nuts (pesto, etc.) 16
ANGIOSPERMS Angiosperm means covered seed Have flowers Have fruits with seeds Live everywhere dominant plants in the world 260,000 species (88% of Plant Kingdom) Angiosperms are the most successful and advanced plants on earth 17
Evolution of Angiosperms Advancements over gymnosperms: Angiosperms have flowers many use pollinators Fruits and seeds adapted for dispersal 18
Monocot vs. dicot Angiosperms are divided into monocots and dicots As the zygote grows into the embryo, the first leaves of the young sporophyte develop and are called as cotyledons (seed leaves) Monocots have one cotyledon (corn, lily, etc). Dicots have two cotyledons (bean, oak, etc). 19
Monocot vs. dicot Number of cotyledons: one vs. two 20
Monocot vs. dicot Leaf venation pattern: Monocot is parallel Dicot is net pattern 21
Monocot vs. dicot root Monocot: Fibrous root Dicot: Tap root 22
Reproduction of Angiosperms: * Pollination = Pollen falls on a stigma when wind, bees, or bats carry it. (Sugar-rich nectar in the flower attracts bees or bats.) * Fertilization = sperm & egg join together in the flower s ovule. - The zygote develops into the embryo part of the seed. - The ovary around the seed develops into a fruit. (Apples, cherries, tomatoes, squash, etc. are all fruit.) * Dispersal animals eat the fruit and the seeds come out the other end. 23
Life Spans of Angiosperms: * Annuals = complete a life cycle in one year. (pansies, wheat, tomatoes, cucumbers, etc) * Biennials = complete life cycle in two years. (Second year they produce flowers and seeds.) (Parsley, celery, etc) * Perennials = live for more than two years (Oak tree, honeysuckles, etc) (Roots and stems survive the winter) 24
Modified from cmassengale 25