Science 2.1 "How Are Plants Classified?"

vascular system

it moves water + nutrients from one part of this type of system to another by the processes of diffusion + osmosis

xylem

it transports water + inorganic nutrients, such as nitrogen + minerals, from the roots to the rest of the plant

phloem

it transports the food, that the plant makes, to all the cells, including its roots

nonvascular plants

- plants without a vascular system to move water + nutrients (no xylem/phloem)
- absorbs water + nutrients instead (through diffusion + osmosis)
- tend to live in damp environments
- no vascular tissue to support plant (so they are usually only 2-3cm)

ex: moss, liverwort

gymnosperm

- vascular plants (mostly trees) that produce seeds that aren't enclosed in fleshy fruits

- these structures in pollination become eggs in female cones + are fertilized by the sperm in pollen from the males cone from tree branches

- after fertilization, the female cone falls to the ground so the seeds can be deposited in the soil

angiosperm

vascular plants that prouduce seeds in the ovaries of flowers

- some seed bearing plants have flowers that contain both female + male parts; they fertilize their own gametes (egg + sperm)

- other plants have separate female + male parts; they have to reproduce through pollinators (bees/butterflies) that carry pollen from male flower to female flower + have the female egg fertilized by the sperm in male pollen

- once gamete is fertilized, the plant develops fruit to protect the growing seed

spore

- a reproductive cell that can develop into a new individual without being fertilized

- used for reproduction if plants don’t use seeds

- in non-vascular (ex: moss) + vascular plants (ex: fern)

- single-celled

-small and can be blown in the wind or carried by something (animal) to another location

- it can survive poor condition + will produce organisms when conditions are right

sporophyte

- term means, "spore plant"

- it is the form of a plant that produces spores during one part of the two-part reproduction cycle

- the dominant stage of vascular plant life cycle

gametophyte

- means "gamete plant"

-it is a generation of plants that produce gametes

-it is the form of a plant that develops from a spore in the second part of the two-part reproduction cycle

-it is the dominant stage of nonvascular plant life cycle

gametes

a male (sperm) or female (egg) reproductive cell

zygote

-it is formed when sperm and eggs are gametes, and they unite.
-this then later develops into an embryo

sori

the reproductive structures of the sporophyte
-it is often found on the underside of a fern

frond

the leaf of a fern

sporangia

the structures on each sorus that produce spores

domain Eukarya

has multicellular organisms like kingdom Protista, Fungi, Animalia, + Plantae

two main characteristics

- based on how plants are classified:
if they have vascular tissue or seeds

ways of transporting nutrients

1. through the vascular system: plants w/ vascular tissue

2. through the non-vascular system: plants w/ out vascular tissue

vascular plant

- has vascular tissue

- use xylem + phloem to move nutrients + materials from roots, stems, leaves + back

- use diffusion + osmosis

- can grow to a great height due to vascular tissues support (ex: North America Redwoods more than 100 meters)

Plants

- needs nutrients to live (like all living organisms)
- they rely on diffusion + osmosis to absorb water + nutrients
-produce food through photosynthesis

diffusion

- the natural tendency of molecules to move from an area of of great concentration to an area of lesser concentration

- method used when gases exchange during photosynthesis

osmosis

- water being diffused across a semipermeable membrane (plant cell)

- during this process, only water moves across the membrane

- water moved both ways across membrane until concentration of other substances are the same

- process is in work when roots absorb water + when the plant moves water upward to the rest of its structures

method of reproduction

vascular plants that produce through:

1. gymnosperms
2. angiosperms

plants are classified by these methods

gymnosperm examples

pine + cedar trees, shrubs, pygmy pine, Morman tea bush

alternation of generations

the two-phased reproduction cycle progess in all plants, where it alernates between a spore (sporophyte) + a gamete (gametophyte)

1: the plant reproduces spores (sporophyte generation)

2: the spores develop into a new plant (gametophyte generation) + produce gametes (egg + sperm)
that unite, creating a zygote which then becomes an embryo

-the embryo will become a sporophyte + the cycle will start over again

(cycle is different for vascular + non-vascular plants

alternation of generations in mosses

gametophyte stage is the dominant stage in non-vascular plants:

1. mature gametophyte produces gametes (egg + sperm)

2. sperm swims in water to egg + combine to form a zygote which develops into a sporophyte plant

3. sporophyte plant grows out of gametophyte plant

4. spore that grows at the end of a thin stalk gets enclosed in a capsule + is released when matured

5. spores fall on ground + germinates to create a protonema which will turn to a gametophyte plant (and the cycle restarts)

angiosperm examples

marigold, oranges, water lillies

alternation of generations in a fern

sporophyte stage is the dominant stage in vascular plants:

1. reproductive structures (sori) of sporophyte located on the frond (leaf of a fern) contain sporangia that produce spores that fall on the ground

2. spores germinate when conditions are right + become a prothallus (a gametophyte plant)

3. gametophyte plant produces the male + female reproductive structures (egg + sperm). sperm swims to fertilize the egg + become a zygote, which becomes a sporophyte plant

4. tiny sporophyte grows + develops fronds + a rhizome (underground stem). when fronds are mature, the sori release spores (and the cycle restarts)