Flashcards in Ch. 12 Plants Deck (37):
The life cycle of plants is characterized by
Alternation of generations. - 1) Gametophyte generation : all the cells of the plant body are haploid (n).
2) Sporophyte generation : the cells of the plant body are diploid.
Plants with no transport vessels - Non-vascular plants
Bryophytes ex) Mosses, liverworts, hornworts
Plants with transport vessels - Vascular plants
Vascular plants - Seedless plants
Like Ferns. reproduce by spores
Vascular plants - Seed plants
2. Angiosperms (Flowering plants)
Cone-bearing. ex) cedars, sequoias, redwoods, pines, yews and junipers.
Flowering plants. ex) roses, daisies, apples and lemons.
1) Monocotyledon (monocots)
2) Dicotyledon (dicots)
Ex) grasses such as corn, wheat, rye and oats
-Lack transport vessels ( xylem and phloem) and absorb water by diffusion from the air.
-Their flagellated sperm must swim through water to fertilize an egg.
-Also lack any lignin-fortified tissue that supports a tall plant.
-Restricted to moist habitats and are tiny.
-Grow on rocks, soil and trees.
-Sphagnum or peat moss is used as fuel in much of the world.
-With vascular tissue.
- Xylem and phloem for transport
- Lignified transport vessels to support the plant
- Roots to absorb water while also anchoring and supporting the plant
-Leaves that increase the photosynthetic surface
-Life cycle with a dominant sporophyte generation.
Ferns - Seedless plants
-Seedless tracheophytes. Primitive plants.
-Reproduce by spores instead of by seeds.
- Homosporous - they produce only one type of spore which then develops into a bisexual gametophyte.
- restricted to moist habitats.
- Their sperm are flagellated and must swim from the antheridium to the archegonium to fertilize the egg.
Heterosporous. produce two kinds of spores.- Megaspores and microspores.
Megaspores- develop into female gametophytes.
Microspores - develop into male gametophytes.
Teh sperm of seed plants have no flagella and do not require a watery environment in order for fertilization to occur. Two types of seed plants, gymnosperms and angiosperms.
Gymnosperms : Conifers
First seed plants to appear on Earth. The seed of gymnosperm - naked, because they are not enclosed inside a fruit as are seed in angiosperms.- form cones.
-Dry environment.: needle- shaped leaves. have a thick, protective cuticle and a relatively small surface area.
- Depend on wind for pollination.
- Ex) gymnosperms are pines, firs, redwoods, junipers and sequoia.
Cotyledons (seed leaves)- Monocots and Dicots
Dicots : two
Vascular bundles in stem - Monocots and Dicots
Dicots: In a ring
Monocots: Usually in 3s
Dicots: Usually in 4s or 5s
Monocots: Fibrous roots
Strategies that enabled plants to move to land
Cell Walls: made of cellulose lend support to the plant whose cells, unsupported by a watery environment, must maintain their own shape.
Roots and root hairs (enabled plants to move to land)
absorb water and nutrients from the soil
Somates (enabled plants to move to land)
open to exchange photosynthetic gases and close to minimize excessive water loss
Cutin (enabled plants to move to land)
the waxy coating on the leaves. Helps prevents excess water loss from the leaves
Gametangia (enabled plants to move to land)
In some plants, gametes and zygotes form within a protective jacket of cells called gametangia. prevents drying out.
a tough polymer. is resistant to almost all kinds of environmental damage and protects plants in a harsh terrestrial environment. Found in the walls of spores and pollen.
Seeds and pollen
Have a protective coat that prevents desiccation. (건조) a means of dispersing offspring.
Primary and secondary growth
plants continue to grow as long as they live because they contain tissue called meristem that continually divides and generates new cells.
Continually divides and generates new cells.
The enlongation of the plant down into the soil and up into the air
The source of primary growth
Apical meristem at the tips of the roots and in the buds of shoots.
provides secondary growth. which is increase in girth. (둘레)
Plants that have only primary growth
In herbaceous (nonwoody)
Plants that secondary growth is responsible for the gradual thickening of the roots and shoots formed from earlier primary growth
In woody plants.
Three types of Plant tissue
Dermal tissue, Vascular tissue, and ground tissue.
covers and protects the plant. includes epidermis and modified cells like guard cells, root hairs and cells that produce a waxy cuticle.
consists of xylem and phloem. Transport water and nutrients around the plant.