PLANTS

• PLANTS ARE ADAPTED TO LIVING ON LAND

• MOST MOSSES AND FERNS LIVE IN MOIST ENVIRONMENTS

• SEEDS AND POLLEN ARE REPRODUCTIVE ADAPTATIONS

• MANY PLANTS REPRODUCE WITH FLOWERS AND FRUIT.

PLANTS ARE ADAPTED TO LIVING ON LAND

• Plants are a diverse group of organisms.• Plants share common characteristics• Plant parts have special functions

– Roots: anchor plant in ground, absorb water & nutrients from soil (transported to leaves via stems)

– Stems & Leaves: make up shoot system; leaves use materials from roots & CO2 from air to make sugars/carbohydrates (& O2); stems then deliver these energy-rich compounds back to rest of plant

• Plants grow throughout their lifetimes.

PLANTS ARE DIVERSE• Plants are nearly

everywhere; they come in all sizes, & shapes.

• Plants are found in all types of environments, from icy arctic to steamy tropics

Share Common Characteristics

• Plants are multi-cellular organisms

• A plant cell has a nucleus and is surrounded by a cell wall.

• Plants are producers. They capture Energy from the Sun.

• Plant life cycles are divided into 2 stages, or generations.

Special Functions• In most plants, materials move through a vascular system in the stems, made of long, tubelike cells.

• Xylem tissue are big tubes taking water & nutrients up to leaves. Phloem tissue are smaller &take sugars/carbs down from leaves.

Special Functions• Plants make sugars via photosynthesis, which takes place in

green chloroplasts full of chlorophyll(absorbs sunlight, mostly in upper leaf); vascular tissue in center of leaf brings in WATER & NUTRIENTS and carries away SUGAR/CARBS;

• Tiny openings at bottom of leaf (STOMATA) lets in CO2 gas & stores it as oxygen is released. (this is known as gas exchange)

• 6CO2 + 6H20 + sunlight C6H1206 + 6O2

• Stomata also let water evaporate out of the leaf(this is called transpiration); both sunlight & wind cause water to transpire/evaporate.

SPECIAL FUNCTIONS• Surface of leaf & stem

has waxy protective layer (cuticle), keeping water from evaporating.

• When air is dry, stomata can close.

• Spines of cactus are modified leaves (regular leaves would loose too much water); photosynthesis occurs in the fleshy green stem, which also stores water & carbon dioxide gas.

Plants Grow throughout Life• Plants continue to grow till die (cells at tips of roots & stems

divide quicker)• Leaves only grow on stems from growth tissue.• Stems have vascular system(to transport materials between leaf &

root) which gives support through stiff fibers and gives plant its shape. Can also store sugars made by photosynthesis (broccoli).

• Soft stem plants have stems & leaves that die in bad weather but roots survive (store sugar) to re-grow stems & leaves back in good weather.

• Woody Stem plants have stems that don’t die each year but grow longer & thicker; form special xylem called “wood”; growing tissue near outer surface (so older wood in middle of tree).