Seed Plants

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

Your Textbook picture Double fertilization: 2 sperm cell + egg + polar nuclei  Zygote (2n) Endosperm (3n)

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

Flowers Sexual reproductive structures (contain gametophytes)  Attract pollinators  Make gametes by mitosis Anther makes pollen containing sperm Ovary makes ovules  eggs Seeds/fruits develop from flower ovary  Pollination – stigma receives pollen, pollen tube forms  Double fertilization in ovary: 2 sperm cells + egg --> embryo & endosperm (endosperm = food for embryo)

Flower Structure (use to label the diagram in your notes)

Flower Structure Perfect/complete Flowers have both male & female parts Imperfect Flowers have either male or female parts

Formation of Female Gametophyte -- Terms you need to know/ID: Ovary, ovule, female gametophyte, meiosis, egg & polar nuclei, endosperm, double fertilization

Formation of Male Gametophyte -- Terms you need to know/ID: Anther, male gametophyte (pollen), meiosis, sperm (2, for double fertilization)

Fruits Fleshy Fruits High moisture content Apples, cherries, grapes, strawberries, tomatoes, cucumbers, etc. Dry Fruits Low moisture Walnuts, acorns, wheat kernels, dandelion “parachutes”

Fleshy Fruits PomeDrupe Berry Multiple Aggregate Accessory nhart/repro/fleshyfruits/fleshyfruits.html

Dry Fruits Follicle Nut Policidal capsule Silique repro/dryfruits/dryfruits.html

Dry Fruits Legume Samara Winged schizocarp

Asexual Reproduction in Plants Vegetative reproduction – occurs naturally, very fast, via modified ground surface/underground stems that make buds:  Stolons/runners – close to ground surface; ex.: aspen groves (clones), water hyacinths  Rhizomes – underground; ex.: bamboo plants  Tubers – swollen tips of rhizomes; modified for food storage; ex: potatoes  Corms and bulbs – modified for food storage; ex.: tulips, onions Artificial propagation – people do it: cutting, grafting, tissue culture  faster than seeds, produces genetically identical crop – plant regenerates parts Ex: bananas, apples, grapefruits, grapes, potatoes, pears are often grown by artificial propagation