Chapter 26: Seed Plants

Dominant phase of Seed Plants

Sporophyte

True or False: Fertilization is water depedent in seed plants

False

Seed plants are ______

Heterosporous

Sporophylls

modified leaves that produce sporangia

Megaspores

Develop into female gametophyte (seed) —- haploid egg

Microspore

Develop into male gametophyte (pollen) — Produces sperm

Male gametophyte (pollen) is comprised of ____ cells

two (generative cell & pollen tube cell)

Gymnosperms and Angiosperms are ____

sister taxa

Gymnosperm seeds

Naked Seeds, Sheltered by woody leaves called sporophylls

Monoecious

male and female gametes/cones are on same plant

Dioecious

male cones on one plant, female cones on separate plant

Gymnosperms are _______ pollinated

wind

Tracheids in xylem

• Perforated, lignified cells that transport water/minerals

• Dominant xylem cell in gymnosperms

Conifers (Cones)

Dominant phylum of gymnosperms

Gymnosperm are heterosporous

• microsporangia produce male microspores (male pollen cones)

• megasporangia produce female megaspores (female ovulate cones)

Microsporangium produce:

male microspores which becomes male gametophyte which produces pollen

Megasporangium produce:

female megapores which becomes female gametophyte which produces eggs

Gymnosperm generative cell

undergoes mitosis to produce sperm

Gymnosperm pollen tube cell

Grows into pollen tube

Gymnosperm has 3 generations of tissue

Parent sporophyte, Gametophyte and new sporophyte

Angiosperm traits:

Fruit & Flowers

Angiosperm are pollinated by

wind, insects, mammals

Angiosperm xylem has

Vessel cells in xylem tissue

• More efficient than tracheids at conducting water

Gynoecium is the

female flower (carpel or pistil)

Each carpel consists of a

stigma, style, and ovary

Megasporangia

• Each ovary contains one or more ovule

• Each will develop into a seed if fertilized

Stigma is

Sticky surface to trap pollen

Style

the tube through which the pollen tube will grow

Androeciumis is the

male flower (stamen)

Stamen consist of

filament and anther

filament

the thin stalk that supports the anther

anther

is sac-like structure where pollen (sperm) are located

Angiosperm eggs undergoes mitosis

3 times

Why does Angiosperm eggs undergo mitosis 3 times?

To make 7 cells and 8 nuclei

Angiosperm has double fertilization

• one sperm fuses with eggs

• one sperm fuses with polar nuclei

Monocots

• one cotyledon (leaf)

• Flower parts are in symmetry of 3 or 6

  • 3 petals, 3 sepals

  • 6 petals, 6 sepals

• fibrous roots

• Scattered Vascular bundles

Eudicots

• two cotyledons (leaves)

• Flower parts are in symmetry of 4 or 5

• 4 petals, 4 sepals

• 5 petals, 5 sepals

• tap roots

• Ringed vascular bundles