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Characteristics That All Plants Have in Common :

•Eukaryotic

•Multicellular

•Autotrophic

•Cell Walls made of cellulose

KINGDOM PLANTAEBotany = the study of plants

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Menu of Knowledge

Plant Classification

Plant Body PartsTransport of Materials

In PlantsGrowth of Plants

Plant Reproduction Plant Hormones

Tropisms andPhotoperiodism

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Plant Classification

Kingdom Plantae

Non-Vascular Vascular

Seedless Produce Seeds

Monocots

Gymnosperms

Dicots

Angiosperms

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Non-Vascular PlantsNon-Vascular Plants = plants without tubes for transporting water, minerals, and organic molecules (such as sugar).

Examples of non-vascular plants = mosses and liverworts. These are called Bryophytes.

Moss

Liverwort

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Vascular PlantsVascular plants = plants with tubes to transport water, minerals, and organic molecules (such as sugars).

Examples of Vascular Plants = all plants except mosses and liverworts

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Seedless PlantsSeedless Vascular Plants = plants with transport tubes but do NOT produce seeds

Examples = Ferns and Horsetails

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Plants That Produce Seeds

All plants except mosses (and other Bryophytes) and ferns are plants that produce seeds.

There are two groups of plants that produce seeds :

Gymnosperms and Angiosperms.

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Gymnosperms

All plants that have transport tubes and produce seeds, but have the seeds unprotected are Gymnosperms.

Gymnosperms = “naked seeds” or unprotected seeds

Examples of Gymnosperms = pine trees, fir trees, ‘conifers’, the “Christmas Tree” group.

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AngiospermsPlants with protected seeds, or

Flowering PlantsAll plants EXCEPT mosses, ferns, pine trees and their relatives are Angiosperms.

Angiosperms can be divided into two groups : Monocots and Dicots

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Monocots vs. Dicots

Monocots and Dicots are the two divisions of Angiosperms (flowering plants). They are different based on the characteristics described on the next slide.

All plants EXCEPT mosses, ferns, pine trees and their relatives are Angiosperms.

All angiosperms are either monocots or dicots.

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Monocots vs Dicots• Monocots• Have one seed leaf

(cotyledon)• Have fibrous roots• Have parallel leaf

veins• Have flower parts in

3’s

• Dicots• Have 2 seed leaves

(cotyledons)• Have tap roots• Have Pinnate or

Palmate leaf vein pattern

• Have flower parts in 4’s or 5’s

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Examples of Monocots and Dicots

• Monocots

• Grass, tulips, corn, wheat, daffodils, iris, Palm trees.

• Dicots

• All flowering plants except the Grass families and the Bulb families.

• These are the most successful plants on Earth.

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Plant Body Parts

The body of a plant is composed of :

Roots

Stems

Leaves

Flowers

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Plant Body Parts - RootsFunctions :

1. Anchoring and stability

2. Absorb water and minerals from the soil

Root Hairs : microscopic threads growing on roots that increase surface area of the root for better absorption of water and minerals.

Monocots

Dicots

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http://www.ars.usda.gov/s/kids/plants/story1/treeb2.gif

Plant Body Parts - Stems

Functions 1. transport materials throughout the plant2. support the plant & hold the leaves up to the sunlight

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Cross-Section of a Stem

DEFINE : phloem ; xylem ; cambium ; sapwood ; heartwood ; annual ring

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http://fig.cox.miami.edu/~cmallery/150/phts/leaf.jpg

Plant Body Parts - LeavesFunctions :

1. To perform photosynthesis to make sugars and other organic compounds.

2. To allow for exchange of gases with the atmosphere (CO2 in and O2 & H2O out).

Veins

Cuticle

Mesophyll

Stomata

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http://www.emc.maricopa.edu/faculty/farabee/BIOBK/C4leaf.gif

Plant Body Parts – Leaves(Continued)

Veins = tubes (vascular tissue) to transport water, minerals, sugars, & other organic molecules.

= 2 types of tubes : Xylem transports water & minerals.

Phloem transports sugars & organics.

Cuticle = waxy layer on leaf surface for water-proofing.

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http://sci.gallaudet.edu/soarhigh2002/amandakrieger/leafinsideparts.jpg

Plant Body Parts – Leaves(Continued)

Cuticle

Vein

Mesophyll = “middle” of leaf made of cells that are green with chlorophyll and do photosynthesis.

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Plant Body Parts – Leaves(Continued)

Stomata = openings (holes), mostly on the underside of leaves to allow for exchange of gases (CO2 in and O2 & H2O out).

Guard Cells = two cells that surround the stomata. They can open or close to regulate water loss and gas exchange.

Stomata

Guard Cells

Closed Stomata

Open Stomata

These are microscope images from the underside surface (epidermis) of a leaf.

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http://www.enchantedlearning.com/subjects/plants/printouts/floweranatomy.shtml

Plant Body Parts - FlowersFlowers = the reproductive structure of a flowering plant

(flowering plants = angiosperms).

Flowers have three primary parts: male, female, and sterile (protection & attraction) parts.

1. Male parts = stamen (made of filament & anther)

2. Female parts = carpel (made of stigma, style, & ovary)

3. Sterile parts = sepals and petals

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http://kvhs.nbed.nb.ca/gallant/biology/flower.jpg

Plant Body Parts – Flowers (Continued)

Click for Plant Reproduction

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Transport of Materials in Plants

Transport of materials in plants occurs through two types of tissue: xylem and phloem

1. Xylem = dead cells with thick cell walls that transport water and minerals up a plant to other plant parts.

= “wood” is xylem tissue

2. Phloem = cells (found on the inside of bark) that transports sugars and organic molecules from the leaves to other plant parts.

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Transport of Materials in Plants(Continued)

Transport of Water and Minerals :Occurs in xylem tubes

Water and minerals travel from roots to rest of the plant

Evaporation of water from leaves “pulls” water through the plant

Evaporation of water from leaves is called

transpiration

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Transport of Materials in Plants(Continued)

Transport of sugars and organic molecules :Occurs in phloem tubes

Sugars and organic molecules travel from leaves (where photosynthesis occurs) to other plant parts

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Growth of PlantsPlants are either annuals, biennials, or perennials.

Plants have indeterminate growth – they continue to grow throughout their lives.

Plant growth in length is called primary growth and it only occurs at the tips of roots and stems. The tips of roots and stems where cell division for plant growth in length occurs are called apical meristems.

Plant growth in thickness is called secondary growth. This occurs in the lateral meristem (= vascular cambium) which is located between the xylem and phloem of a stem.

Annuals, Biennials,Perennials

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Plant ReproductionMale part of flower = stamen, which produces pollen in the anther of the stamen. Pollen contains plant sperm.

Female part of flower = ovary, which is at the base of the pistil and produces the egg.

These images are pollen grains containing plant sperm.

Click here to review Flower Anatomy

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http://www.urbanext.uiuc.edu/gpe/glossary/fertilization.html

Plant Reproduction - Pollination

Pollination = transfer of pollen (containing sperm) from the anther of a flower to the stigma of the pistil of a flower.

Pollination & Fertilization

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Plant Reproduction(Continued)

Seed = a protective structure that contains the plant embryo and stored food and is covered with a protective seed coat.

The functions of the seed are to protect and nourish the embryo.

Seeds can remain dormant for years before germination.

Seeds are dispersed (transported) by animals eating them or carrying them to other locations.

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Plant Reproduction(Continued)

Fruit = a ripened ovary that protects the seeds of a plant. The ovary is the base of the pistil at the lower end of a flower.

The fruit contains the seeds. The fruit and seeds are eaten by animals, the fruit is digested and the seeds are passed through the animal digestive tract and deposited in the ground away from the parent plant. This is one way seeds can be dispersed (another way is by the wind, like in dandelions and most trees). Examples of ripened ovaries (fruit) = squash, cucumbers, & tomatoes.

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Plant Hormones

Hormones = proteins made and released from one part of a plant that affect a different part of the plant.

Important plant hormones :

1. auxins

2. cytokinins

3. ethylene

4. gibberellins

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Plant Hormones(continued)

1. Auxins :

Where Produced = At the tips of stems

Functions = Stimulates cell elongation ; controls apical dominance ; functions in tropisms.

Apical Dominance = the tendency for plants to grow upward (towards sunlight) and inhibit side (axillary) shoots from forming. Auxins control this. (Pruning house plants cuts

off the tips of plants, removing auxins, and letting side branches grow. This results in ‘fuller’ or ‘bushier’ plants.)

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Plant Hormones(continued)

2. Cytokinins :

Where Produced = roots

Functions = Stimulates cell division; stimulates germination of seeds.

3. Ethylene :

Where Produced = in fruits

Function = Ripening of fruit

Unique Characteristic = ethylene is a gas. One over-ripe fruit in a bag can cause all other fruits in the bag to over-ripen. (“One bad apple can spoil the whole barrel”)

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http://www.usu.edu/cpl/images/29lu1sd.jpg

Plant Hormones(continued)

4. Gibberellins :

Where Produced = Tips of stems and in seeds

Functions = Stimulates stem elongation; stimulates germination of seeds.

Tall plant has Gibberellins,

Short plant does not.

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Tropisms and PhotoperiodismTropisms = the growth of a plant in a certain direction in response to a stimulus.

1. Phototropism (bending in response to light)

2. Gravitropism (bending in response to gravity)

3. Thigmotropism (bending in response to contact)

Photoperiodism = any response of a plant that is linked to day length (ex = flowering, leaves changing color, etc.)

Roots bending towards gravity

Coiling in response to touch

Bending in response to light

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Selected Vocabulary• Annual ring = a light-colored ring of spring/early

summer xylem growth and a dark ring of late summer xylem growth.

• Apical meristem = tips of stems and roots where cell division and primary growth (growth in length) occurs.

• Heartwood = oldest xylem in center of trunk that no longer transports water because the cells are filled with plant wastes (it’s a darker color).

• Sapwood = newer xylem that can still transport water (it’s a lighter color).

• Vascular cambium = ring of tissue between xylem and phloem that divides to produce new xylem and phloem and causes secondary plant growth (growth in thickness).

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