Ch28 Seed Plants

Gymnosperms and angiosperms reproduce by ________, an adaptation to life on land

• each seed has an __________, __________, & __________

seeds

• embryonic sporophyte, nutritive tissue, and a protective coat

3 advantages of seeds over spores

• a seed is farther along in its development before it is released to survive on its own

• a seed contains an abundant food supply that nourishes the plant embryo

• a seed us protected by a multicellular seed coat that is very thick and hard

Alternation of generation life cycles

• sporophyte generation is the dominant/non-dominant stage

• female gametophyte is attached to and nutritionally dependent on the ______________ ____________

• dominant

• sporophyte generation

All seeds are heterosporous/homosporous

heterospor

Seed plants have __________ tissues; __________ & __________

vascular; xylem & phloem

Seed plants produce _______, each of which is a megasporangium surrounded by layers of ___________ ________that enclose the x

ovules, sporophyte tissue

After fertilization, ovule develops into a _______, integuments develop into the ______ ______

seed, seed coat

Gymnosperms have seeds that care totally exposed or borne on scales of ________

• no ovary wall surrounds the _______

cones

• ovules (ex: pine, spruce, fir)

Angiosperms are flowering plants that produce seeds within a _______ _______ (fruit)

mature ovary

(ex: corn, oaks, water lilies, cacti, apples)

Four phyla of gymnosperms

Conifers (coniferophyta)

Ginkgoes (ginkophyta)

Cycads (cycadophyta)

Gnetophytes (gnetophyta)

woody trees or shrubs that produce annual additions of secondary tissues

• may produce resin

• most have long, narrow, tough needles; some have small, scalelike leaves

• most are evergreen, few are deciduous

• most are monoecious; reproductive parts are borne in male and female strobili (cones)

conifers (phylum coniferophyta)

A male cone consists of ___________ that bear ________ on the underside

sporophylls, sporangia

• Microsporangia contain _____________, each of which undergoes meiosis to form four ___________ ____________

• Microspores develop into pollen grains consisting of _____ ______, two of which are involved in reproduction

• microsporocytes, haploid microspores

• four cells

• Each cone scale of a female cone bears ____ ________________ on its upper surface

• Within each megasporangium, meiosis of a megasporocyte produces….

• one megaspore divides by mitosis, developing into the _______ gametophyte, which produces an ___ within each of several archegonia

• two megasporangia

• four haploid megaspores

• female, egg

tropical and subtropical plants with trunklike stems and compound leaves resembling those of palms or tree ferns

• reproduction is similar to that in pines, except that cycads are _________

• sperm cells are motile; have hairlike ________

• specialized insects carry pollen to ________ cones

cycads (phylum cycadophyta)

• dioecious

• flagella

• female

a single extant species

• leaves are _________

• dioecious, with separate ________ & ________ trees

• flagellate _____ cells and airborne pollen grains

• seeds are/are not completely exposed

Ginkgo (phylum ginkgophyta)

• deciduous

• male and female

• sperm

• are

the only gymnosperms with efficient vessel elements in their xylem, cone clusters that resemble flower clusters; & life cycles with similarities to those of flowering plants

• Include three genera:

• __________ is the source of ephedrine (stimulates heart & raises blood pressure)

Gnetophytes (Phylum gnetophyta)

• gnetum, ephedra, welwitschia

• ephedra

_____________ are earths dominant plants

• reproduce sexually by forming ________; have double fertilization; form seeds within ________

• fruit protects developing seeds and aids in dispersal

• have vessel elements in their ______ and sieve tube elements in their ______

angiosperms

• flowers, fruits

• xylem, phloem

Two largest classes of flowering plants

Monocots (class monocytyledones) & Eudicots (class eudicotyledones)

Herbaceous plants with long, narrow leaves that have parallel veins

• flower parts usually occur in _____

• seeds have a single _______

• endosperm is usually present in the ________ ______

• (ex: palms, grasses, orchids, irises, onions, lilies)

Monocots

• threes

• cotyledon

• mature seed

Herbaceous or woody plant with broader leaves than monocots, with netted veins

• flower parts occur in multiples of _______ or _______

• seeds have ___ cotyledons

• endosperm is usually ________ in the mature seed

• (ex: oaks, roses, mustards, cacti, blueberries, sunflowers)

Eudicots

• fours or fives

• two

• absent

Flowers are __________ ______ composed of ____ parts arranged in whorls on the end of a flower stalk (peduncle)

• only _______ & ________ produce gametes

• a complete flower has all _____ parts; an incomplete flower lacks ___ or more parts

• a flower with _____ stamens and carpels is perfect; an imperfect flower has stamens or carpels, but not ______

reproductive shoots, four

• stamens & carpels

• four, one

• both, both

_______ make up the lowermost and outermost

• cover and protect other flower parts in ____

• all sepals of a flower make up the ______

Sepals

• buds

• calyx

_______:the whorl inside the sepals

• _____ _____ attract animal pollinators to the flower

• all petals of a flower make up the _________

Petals

• bright colors

• corolla

_________: the whorl inside the petals

• each stamen has a thin filament and saclike another where meiosis occurs and microspores develop into pollen grains

• each pollen grain produces ___ cells:

  -one cell divides to form ___ male gametes (sperm cells)

  -the other produces a _______ _____ through which sperm cells travel to reach the _____

Stamens

• two

  • two

  • pollen tube

  • ovule

________: the center whorl of most flowers

• closed female reproductive organs, bearing ovules that develop into _____

• may be separate (______) or fused into a single structure (_______)

Carpels

• seeds

• simple, compound

Each pistil has three sections:

• a stigma on which the pollen grain lands-

• a style through which the pollen tube grows

• an ovary that contains one or more ovules

• Each ovule contains a female gametophyte that forms one ________ ________, two ______ _______, and other _______ _____

• after fertilization, the ovule develops into a ______ and the ovary develops into a ______

• female gamete, polar nuclei, haploid cells

• seed, fruit

A process called: ______ ___________

• One sperm cell fuses with the egg, forming a _______ that grows into an _______ in the seed

• the second sperm cell fuses with the two haploid polar nuclei of the central cell to form a ______ (3n) cell that grows by mitosis and develops into ________

• endosperm is rich in ______, ________, & ___________ that nourishes growing embryo

double fertilization

• zygote, embryo

• triploid, endosperm

• lipids, proteins, carbohydrates

Each seed contains a plant embryo ___________, both surrounded by a protective seed coat

• in _______ , the endosperm is the main source of food in the mature seed

• in most ________, the endosperm nourished the embryo, which stores food in its cotyledons

endosperm

• monocots

• eudicots

as a seed develops, ovary wall surrounding it enlarges and develops into a ______

fruit

• seeds, fruits, and endosperm increase likelihood of ___________ _______

• coevolution with pollinators increases cross-pollibatuib and promotes ________ _________

• vascular systems with vessel elements and sieve tube elements increase __________

• leaf, stem, and root adaptations allow plants to live in….

• reproductive success

• genetic variation

• efficiency

• a variety of habitats

• botanists generally agree that sepals are specialized _______

• botanists generally view petals as modified _______ that later became sterile and leaflike

• leaves

• stamens

Progymnosperms had two derived features:

• megaphylls;

• secondary xylem;

• leaves with branching veins

• woody tissue

• the fossil record suggests that flowering plants descended from _____________

• the oldest fossil trace of flowering plants consists of _____ enclosed in tiny podlike fruits found in jurassic and lower cretaceous rocks

• gymnosperms

• ovules

comprise of three clades thought to be ancestral to all other flowering plants

basal angiosperms

First clade:

Second clade:

Third clade:

single extant species

water lilies and related families

~100 species of vines, trees, shrubs

most angiosperm species belong to a clade of core angiosperms, which is divided into three subclades:

the core angiosperms

• magnoliids, monocots, eudicots