Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Overview: Transforming the World Seeds changed the course of plant evolution, enabling their bearers to become the dominant producers in most terrestrial ecosystems A seed consists of an embryo and nutrients surrounded by a protective coat Naked seed vs protected seed

Fig. 30-1

Fig. 30-UN1 Nonvascular plants (bryophytes) Seedless vascular plants Gymnosperms Angiosperms

Fig Archaeopteris, a progymnosperm

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Phylum Cycadophyta Individuals have large cones and palmlike leaves These thrived during the Mesozoic, but relatively few species exist today

Fig. 30-5a Cycas revoluta

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Phylum Ginkgophyta This phylum consists of a single living species, Ginkgo biloba It has a high tolerance to air pollution and is a popular ornamental tree Ginkgos are in this group because they have no seed coat but have a protective scale

Fig. 30-5b Ginkgo biloba pollen-producing tree

Fig. 30-5c Ginkgo biloba leaves and fleshy seeds

Fig. 30-5d Gnetum

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Phylum Gnetophyta This phylum comprises three genera Species vary in appearance, and some are tropical whereas others live in deserts

Fig. 30-5f Welwitschia

Fig. 30-5g Welwitschia Ovulate cones

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Phylum Coniferophyta This phylum is by far the largest of the gymnosperm phyla Most conifers are evergreens and can carry out photosynthesis year round

Fig. 30-5h Douglas fir

Fig. 30-5k Sequoia

Fig. 30-2c Reduced (usually microscopic), dependent on surrounding sporophyte tissue for nutrition Dominant Seed plants (gymnosperms and angiosperms) Gymnosperm Angiosperm Microscopic female gametophytes (n) inside ovulate cone Microscopic male gametophytes (n) inside pollen cone Sporophyte (2n) Microscopic female gametophytes (n) inside these parts of flowers Microscopic male gametophytes (n) inside these parts of flowers Example Gametophyte Sporophyte

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Concept 30.3: The reproductive adaptations of angiosperms include flowers and fruits Angiosperms are seed plants with reproductive structures called flowers and fruits They are the most widespread and diverse of all plants

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Characteristics of Angiosperms All angiosperms are classified in a single phylum, Anthophyta The name comes from the Greek anthos, flower

Fig d Southern magnolia

Fig f

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Flowers The flower is an angiosperm structure specialized for sexual reproduction Many species are pollinated by insects or animals, while some species are wind- pollinated

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings A flower is a specialized shoot with up to four types of modified leaves: – Petals, which are brightly colored and attract pollinators – Sepals, which enclose the flower – Pistil/Carpels female structure which produce ovules – style-tube, stigma –sticky, ovary – organ for reproduction, ovule- inside contains seed – Stamens male structure which produce pollen on their anthers- contains sperm = pollen, these are held up by filaments

Fig Carpel Ovule Sepal Petal Stigma Style Ovary Stamen Anther Filament

Toxic : Amarylis, Flamingo Lily, Arum Lilies, Calla Lilies, Autumn Crocus, Azaleas, Bird of Paradise, Bittersweet, Black-eyed Susan, Bleeding Heart, Bluebell, Burning Bush, Buttercup,, Chrysanthemum, Clivia, Cobra Lily, Common vetch, Corncockle, Corn Poppy, Crocus, Daffodil, Jonquil, Daphne, Delphinium, Flame Lily, Fly honeysuckle, Foxglove, Holly Berry, Horse Chestnut, Hyancinth, Hydrangea, Iceland Poppy, Iris, Ivy, Jack-in-the-Pulpit, Larkspur, Lenten Rose, Leopard Lily, Lily-of-the-valley, Lily family, Lobelia, Lupins, Marsh Marigold, Mistletoe, Morning Glory, Narcissus, Night Blooming Jasmine, Oak, Oleander, Opium Poppy, Oriental Poppy, Peace Lily, Peruvian Lily, Philodendron, Snowdrop, Scarlet Pimpernel, Star of Bethlehem, St.Johns Wort, Sweet Pea, Sun Flower, Tobacco Plant, Tulip, Virginia Creeper, Weeping Fig, Wisteria. LOW TOXICITY: African violet, Busy Lizzie, Chinese Lantern, Clematis, Fuchsia, Grape Hyacinth, Honesty, Mahonia, Poinsettia.

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Sexual Reproduction of seed plants Inside the ovary, produce megaspores which form eggs which give rise to female gametophytes Inside the anther, produce microspores which form sperm (pollen) that give rise to male gametophytes

Fig Megasporangium (2n) Megaspore (n) (a) Unfertilized ovule Integument Spore wall Immature female cone

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Angiosperm Life Cycle The flower of the sporophyte is composed of both male and female structures The female gametophyte, or embryo sac, develops within an ovule contained within an ovary (megasporangia)at the base of a stigma where the pollen is received The Male gametophytes are contained within pollen grains produced by the structure in (microsporangia) anthers Most flowers have mechanisms to ensure cross- pollination between flowers from different plants of the same species

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fig Carpel Ovule Sepal Petal Stigma Style Ovary Stamen Anther Filament

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Pollination is the transfer of pollen to the part of a seed plant containing the ovules A pollen grain that has landed on a stigma germinates and the pollen tube of the male gametophyte grows down to the ovary Double fertilization occurs when the pollen tube discharges two sperm that moves down the style toward the ovary/ovule The ovule is entered by a pore called the micropyle

Fig Male gametophyte (within a germinated pollen grain) (n) Female gametophyte (n) (b) Fertilized ovule Micropyle Pollen grain (n) Spore wall Discharged sperm nucleus (n) Egg nucleus (n)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings One sperm fertilizes the egg, while the other combines with two nuclei in the central cell of the female gametophyte and initiates development of food-storing endosperm The endosperm nourishes the developing embryo. The zygote toughens to form a seed coat. The ovary wall will become a fruit.

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings The Evolutionary Advantage of Seeds A seed develops from the whole ovule A seed is a sporophyte embryo, along with its food supply, packaged in a protective coat Seeds provide some evolutionary advantages over spores: – They may remain dormant for days to years, until conditions are favorable for germination – Germination wet seeds hormones washed away grow when they break dormancy – They may be transported long distances by wind or animals

Fig Seed coat (derived from integument) (c) Gymnosperm seed Embryo (2n) (new sporophyte) Food supply (female gametophyte tissue) (n)

Fig Seed coat (derived from integument) (c) Gymnosperm seed Embryo (2n) (new sporophyte) Food supply (female gametophyte tissue) (n) (b) Fertilized ovule(a) Unfertilized ovule Integument Immature female cone Spore wall Megasporangium (2n) Male gametophyte (within a germinated pollen grain) (n) Megaspore (n) MicropylePollen grain (n) Egg nucleus (n) Discharged sperm nucleus (n) Female gametophyte (n)

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Fruits/Roots/Leaves Within a seed, the embryo consists of a root and seed leaves called cotyledons A fruit typically consists of a mature ovary but can also include other flower parts Fruits protect seeds and aid in their dispersal Mature fruits can be either fleshy or dry Animation: Fruit Development Animation: Fruit Development

Fig Hazelnut Ruby grapefruit Tomato Nectarine Milkweed

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Various fruit adaptations help disperse seeds Seeds can be carried by wind, water, or animals to new locations

Fig Barbs Seeds within berries Wings

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Video: Flowering Plant Life Cycle (time lapse) Video: Flowering Plant Life Cycle (time lapse) Animation: Seed Development Animation: Seed Development Animation: Plant Fertilization Animation: Plant Fertilization

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings

Fig b Water lily

Fig c Star anise

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Monocots More than one-quarter of angiosperm species are monocots

Fig e Orchid

Fig e1 Pygmy date palm (Phoenix roebelenii)

Fig g Anther Barley Stigma Ovary Filament

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Eudicots More than two-thirds of angiosperm species are eudicots

Fig h California poppy

Fig i Pyrenean oak

Fig j Dog rose

Fig k Snow pea

Fig l Zucchini flowers

Fig m Monocot Characteristics Eudicot Characteristics Vascular tissue usually arranged in ring Veins usually parallel Veins usually netlike Vascular tissue scattered Leaf venation One cotyledon Embryos Two cotyledons Stems Roots Pollen Root system usually fibrous (no main root) Pollen grain with three openings Taproot (main root) usually present Pollen grain with one opening Floral organs usually in multiples of three Flowers Floral organs usually in multiples of four or five

Fig n Monocot Characteristics Eudicot Characteristics Vascular tissue usually arranged in ring Veins usually parallel Vascular tissue scattered Leaf venation One cotyledon Embryos Two cotyledons Stems Veins usually netlike

Fig o Roots Pollen Root system usually fibrous (no main root) Pollen grain with three openings Pollen grain with one opening Floral organs usually in multiples of three Flowers Floral organs usually in multiples of four or five Monocot Characteristics Eudicot Characteristics Taproot (main root) usually present

Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Products from Seed Plants Most of our food comes from angiosperms Six crops (wheat, rice, maize, potatoes, cassava, and sweet potatoes) yield 80% of the calories consumed by humans Modern crops are products of relatively recent genetic change resulting from artificial selection Many seed plants provide wood Secondary compounds of seed plants are used in medicines

Table 30-1a