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Introduction to Angiosperms! "Flowering Plants" Overview Quick Review! Gymnosperms Naked seed Cones as reproductive structures Thin, needle like leaves Large growing plants Video: http://www.youtube.com/watch?v=ph7Ex8rQ-IA Another class of seed plants: Angiosperms Overview of lesson
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Introduction to Angiosperms! "Flowering Plants"
Quick Review!Gymnosperms • Naked seed • Cones as reproductive structures • Thin, needle like leaves • Large growing plants Video: http://www.youtube.com/watch?v=ph7Ex8rQ-IA
Another class of seed plants: Angiosperms • Overview of lesson • Adaptive features • Flowers • Fruits • Unique reproductive cycle
Flowers • Modified leaves • Reproductive structures • Allow for greater reproductive success • More attractive
Structures of a flower • Petals • Sepal • Stamen • Anther • filaments • Pistil • Stigma • Style • ovary
Petals/Sepal • Petals • Highly modified leaves • Brightly colored • Function: attract pollinators • Sepals • Enclose the flower before it opens
Stamen • Male part of the flowers • contain: • Anther: where pollen grains are formed • Filament: stalk that hold anther http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Seed%20Plants/seed%20plants.htm
Pistil (carpal) • Stigma • Sticky part where pollen lands • Style • Slender stalk where pollen grain reaches the ovary • Ovary • Where the ovule (egg) is contained
Fruits! • Once fertilized, ovary becomes fruit- bears seeds • Function: protection and dispersal of seeds Can be either fleshy ex: peaches tomato oranges or dry ex: nuts and raisins
Types of fruits • Simple: flower with only 1 pistil • Apples, tomatoes • Multiple: fruit formed from a cluster of flowers • Fruits fuse into one big mass • pineapples • Aggregate: flower with numerous pistils • Ex raspberries
Reproduction! biology.clc.uc.edu/courses/bio106/angio.htm
Alteration of generation review! • a haploid gametophytic stage alternates (through time and generations) with a sporophytic stage • haploid = 1N number of chromosomes, diploid = 2N
Overview of life cycle • In ovule- production of megaspores (n) via meiosis • Megaspores ---mitosis---megagametophyte • In anther-production of microspores (n) via meiosis • Microspores----mitosis----microgametophyte (pollen grain) http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Seed%20Plants/seed%20plants.htm
Overview of life cycle • Megagametophyte contains egg (n) • Microgametophyte (pollen) produces sperm (n) • Pollen (containing sperm) reaches the ovule • Egg and sperm meet = Fertilization
Overview of life cycle • After fertilization: zygotes embryo (2n) • Fruit develops from ovary • Seed develops from ovule • Seed germinates to form Sporophyte (mature plant) (2n) http://www.ualr.edu/botany/botimages.html
Double fertilizationunique to flowering plants • Once pollen tube enters ovary • 1 sperm fertilizes ovule to form zygote (seed) • Another sperm combines with rest of ovule to form endosperm • Provides nourishment to developing embryo
The growing zygote ( embryo) feeds on the endospore until it grows leaves and can make its own food.
Quiz! http://www.cartage.org.lb/en/themes/Sciences/BotanicalSciences/PlantReproduction/Angiosperms/Angiosperms.htm
How does the pollen get to the pistil???? • Pollination: transfer on pollen to plant pistil • Pollen dispersal agents: • Wind- these pollen grains are light weight,dry and easily blown by wind • Animals- ex: insects. Attracted to brightly colored and sweet smelling flower. This Pollen is sticky and adheres to animals body.
Seed Dispersal • Seeds are dispersed away from parent for decreased competition and increased survival but how??? • Wind- some seeds are lightweight therefore can be carried ex: dandelions • Water- air trapped in seeds that allows them to float ex: water lilies • Animals- • feed on fruit/berries • Stick to body-sticky, spiny seeds