Seed Plants

Classification - SeedsSeedless 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 - FlowersFlowering 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)

(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

YourTextbook 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 coteledongrains: rice, corn, wheat, etc.

Dicot two coteledonslegumes: 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

leavesCotyledons (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 Flowershave both male & female parts

Imperfect Flowershave 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)

FruitsFleshy Fruits High moisture content Apples, cherries, grapes,

strawberries, tomatoes, cucumbers, etc.

Dry Fruits Low moisture Walnuts, acorns, wheat

kernels, dandelion “parachutes”

Fleshy Fruits

Pome Drupe

Berry

Multiple

Aggregate

Accessory

http://www.csdl.tamu.edu/FLORA/201Manhart/repro/fleshyfruits/fleshyfruits.html

Dry Fruits

Follicle

Nut

Policidal capsule

Silique

http://www.csdl.tamu.edu/FLORA/201Manhart/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 partsEx: bananas, apples, grapefruits, grapes, potatoes, pears are often

grown by artificial propagation