Presentation on theme: "Seed Plants. Classification - Seeds Seedless Plants Mosses & ferns (ferns are vascular plants) make spores, not seeds Embryo from sexual reproduction."— Presentation transcript:
Classification - Seeds Seedless Plants Mosses & ferns (ferns are vascular plants) make spores, not seeds Embryo from sexual reproduction develops within archegonium in parent plant Embryo does not need to await favorable conditions to develop Seed Plants Embryo from sexual reproduction develops in seed Seeds dispersed, await favorable conditions to germinate Seeds formed in cone (gymnosperm) or fruit (angiosperm)
Classification - Flowers Flowering Plants: Angiosperms/Anthophyta Seeds enclosed in a fruit Flowers make gametes (eggs & sperm) Fertilized flower fruit Naked Seed Plants: Gymnosperms/Coniferophyta Seeds in cone No flowers Male & female cones make gametes (egg & sperm) Conifers: pines, firs, spruces, cypresses, redwoods
Sexual Reproduction in Seed Plants (ch. 30) Life Cycle of Coniferophyta/Gymnosperms (2n) (n) Pollination *Water not needed* (2n) No more spores… In pollen cone and ovule of female cone: Meiosis to produce gametophytes (n) Mitosis to produce gametes (n) Female gametophyte Male gametophyte
Life Cycle of Anthophyta/Angiosperms Mitosis Fertilization Pollination *Water not needed* No more spores… In anther and ovule: Meiosis to produce gametophytes (n) Mitosis to produce gametes (n) Female gametophyte Male gametophyte
Seed Germination Germination – embryo in seed starts to grow (usually triggered by water absorption) Radicle – first shoot/part of embryo to appear outside seed; develops into root Cotyledons – seed “leaves,” not real leaves, do not photosynthesize Monocot one coteledon grains: rice, corn, wheat, etc. Dicot two coteledons legumes: beans, peas, etc.
If April showers bring May flowers, what do May flowers bring? Pilgrims. Botanists have developed a vegetable that eliminates the need to brush your teeth. Bristle sprouts.
Double fertilization seeds containing embryo and endosperm (one sperm for egg, one for endosperm) Endosperm – contains starch/oil/protein -- energy for developing embryo Seed Structure & Development in Flowering Plants Each ovule develops into a seed. The micropile is the small opening where sperm came into ovule for fertilization.
Hypocotyl = embryo shoot under cotyledons develops into first stem Seed Development Brassica, our lab plant Epicotyl = embryo shoot above cotyledons develops into first leaves Cotyledons (seed leaves) eventually fall off
Bean Seed Micropile Scar where pollen tube entered ovule Hilum Scar where ovule attached to ovary Radicle emerges here, becomes root
Development of Bean Plant cotyledons epicotyl hypocotyl
Embryo Silk Scar (pollen tube entered ovule here) Point of attachment Corn Kernel / Seed / Fruit