Plants as Living OrganismsPlant and Soil Science

The Plant KingdomPlants are found in biomes from the tundra to

the desert. Four Major Groups of plants: mosses, ferns,

gymnosperm, and angiosperm.

Gymnosperm: produce plants that produce seeds on the scales of cones. Ex. Pine, spruce, fir

The Plant KingdomAngiosperm: Flowering plants

Ex. Corn, wheat, apples, petunias, oak Two Classes

Monocots: send up a single cotyledonLong narrow blades, with parallel veins,

flowers in multiples of three, vascular bundles are scattered

Dicots: send up two cotyledonsBroad leaves, netted veins, vascular

bundles in a circle, flowers in fours or fives

The Plant Kingdom- Life CyclesLife Cycle: the time from when a plant begins

growing until it dies

Annual: germinates, grows, and reproduces in one year.

Biennial: two growing seasons, first year they grow, second year they reproduce.

The Plant Kingdom- Life CyclePerennial: life cycle of two or more years

Herbaceous: soft shoots that are killed by frost. Send up new shoots in the spring

Woody: trees, shrubs, and vines above ground that survive winter

Hardy: how tolerant to cold a plant is

Structures- Roots Function:

Absorb water and minerals from soil

Anchor plant

Store food

Structures- Roots Most roots found in top 2 feet of soil

Primary root (radical) is the first root put out by the plant

Root hairs are near the growing tip of the root and increase surface area for absorption.

Structures- Roots Root Systems

Tap Root Thick main root that grows straight down Can work for storage

Ex. Carrots, beets, and radishes Fibrous Root

Branching slender roots Less tolerant of dry conditions Hold soil in place, and prevents erosion

Structures- Roots

Structures- Roots Secondary roots: branch off the primary root

Root cap: tip of root, protects root from soil as the root grows

Structures- Stems Function:

Hold leaves upright

Conduct water and minerals

Conduct food

Store food

Structures- Stems Conducting food and water

Two types of conductive tissue- Xylem and Phloem

Xylem Transports water from the roots up to the leaves

Phloem Transports food to the roots and other parts of the

plant

Structures- Stems/ BudsBuds- contain undeveloped leaves, stems, or

flowers. Bud scales protect the bud.

Terminal bud: large tip of the twig, the growing tip, contains the apical meristemApical meristem is the primary growing point

Lateral buds are located along the sides of the branch

Structures- Modified Stems Some stems have been modified for food

storage and underground growth

Bulbs, corms, rhizomes, and tubers are all examples of modified stems

Structures- Modified Stems Bulbs- tulips and onions, have scales

Structures- Modified Stems Corms- Gladiolus and crocus, fleshy and scale

covered

Structures- Modified Stems Rhizomes- underground stem that produces

branches, irises and lily of the valley

Structures- Modified Stems Tubers- storage organs, potatoes and

caladium

Structures-LeavesResponsible for food production

PhotosynthesisTranspiration

Structure-LeavesComprised of specialized

cellsEpidermis-protective

layers

Cuticle-waxy coating

Stomata-pores allowing O2, CO2, and H2O exchange

Guard cells-controls stomata

(xylem and

phloem)

Structure-LeavesPhotosynthetic tissues

Mesophyll- “Middle of the leave” Bulk of Photosynthesis Palisade layer Spongy layer

Structure-LeavesSimple leaves

Single leaf blade and petiole

CompoundPetiole, 2 or more

leaves called leaflets

Broadleaf Plants- wide flat leaves

Structure-LeavesDeciduous

Looses leave in FallEvergreen

Keep leaves year round

Narrow leaf plants- needle or scale shape leaves

Structures- Flowers

Structures- FlowerFemale- Pistil

Stigma- Top sticky portion to catch the pollen

Style-Tube that carries the pollen to the ovary

Ovaries-Where the seed will develop

Structures- FlowerMale- Stamen

Anther- Holds pollen

Filament- Holds the anther

Pollen- Male gamete