Plant Notes ch 21-24

Introduction to Plants

• What we have learned about plants so far this year:

• 1. Eukaryotic• 2. Multicellular• 3. Autotroph• 4. Cell wall made of cellulose• 5. Has chloroplasts

What plants need to live:

• 1. Water• 2. Soil (nutrients)• 3. Sunlight• 4. carbon dioxide

What plants give to us:

• 1. Oxygen• 2. Energy• 3. Clothing• 4. Medicines• 5. Decorations, dyes, shelter for

animals, industry: glue, furniture

All plants have the following in common:

• Multicellular• Eukaryotic• Cell walls made of cellulose• Photosynthesis

I. Plant Adaptations: Parts of all plants (leaves, stem, and roots)

1A.The leaf –

3parts:• Blade – where photosynthesis takes

place (primary function of leaves)• Vein – carries water, minerals, and

sugars through blade• Petiole – connects the leaf to the

stem, transports fluids

Leaf Type:

• Simple: one blade that is not divided

• Compound: When blade is divided into leaflets

Leaf Arrangement: How the leaves are arranged on the

stem

• Alternate

• Opposite

• Whorled

Leaf Venation: How the leaf veins occur

• Parallel

• Palmate

• Pinnate

3 parts:

• Cuticle - waxy covering over the plant that prevents water loss.

• Stomata – allows gas and water vapor in and out. (found in the dermal layer)

• Guard cells – opens and closes stomata

Leaf structureLeaf structure

StomataGuard cell

Spongy mesophyll

Lower epidermis

Cuticle

Upper epidermis

Palisade mesophyll

Vascular bundle

XylemPhloem

• Cells called guard cells control the opening and closing of stomata.

Dermal tissuesDermal tissues

• The opening and closing of stomata regulates the flow of water vapor from leaf tissues.

• Transpiration – the loss of water through the stomata

• *Trichomes – give the stem or leaf a “fuzzy” appearance, helps reduce the evaporation of water from the plant.

2. The Stem

3 types of tissue

• Dermal Tissue – Outer layer of stems and leaves used for covering & protection(like humans skin)

• Ground Tissue – Storage, support, and photosynthesis

• Vascular Tissue – xylem (dead cells) – carry water and minerals *

Dead xylem makes rings of trees

– phloem (living cells) – carry “food” (sugar produced by plant)

• *Meristems – where new growth occurs

•Merry stems grow

3. The Root

• absorbs water and minerals• anchors plant• some store food• root hairs = increase surface area

for absorption• root tip – site of maximum

absorption of water and minerals

2 root types:• taproot root -

deep strong anchor for plant, gets ground water (carrots, beets)

• fibrous root - found in upper soil, cover wide area, prevent erosion (grass)

4. Reproduction of Plants

• Spores – A plant reproductive organ that requires water to be transported.

• Seeds - a plant organ that contains an embryo, food supply, and has a protective coat

To return to the chapter summary click escape or close this document.

Diagram of a Seed

The FruitThe Fruit – houses the seeds and aids in dispersal by wind, water, insects, and other organisms

– Some have one seed – peach, plum– Some have several seeds –

strawberry, tomato

• 4. Life Cycle is called Alteration of Generations :

• Switching back and forth between diploid and haploid stages.

5. How Plants Are Classified

Divisions of Plants Examples Information Nonvascular Mosses, liverworts,

Hornworts

Smaller, close to ground because of water

Non Seed Vascular Club mosses, horsetails, ferns

Taller and larger

Seed Vascular Angiosperms-fruit Gymnosperms - cone

Plants produce cones or flowers

6. Parts of Flowering Plants:

• Structure• Review words:• Leaf – site of photosynthesis• Stem – supports leaves and flowers• New words:• Flower – reproductive organ• Internode – between nodes • Node - where the leaf attaches

Flowering plants are divided into two groups: (page 595 –

chart )• Distinguishing Characteristics of Monocots and

Dicots

Type Seed leaves Leaf venation Flower parts Monocots

One cotyledon Usually parallel Multiples of 3

Dicots Two cotyledon Usually netlike Multiples of 4 and 5

Moncots and dicotsDistinguishing Characteristics of Monocots and Dicots

Seed Leaves

Vascular Bundles in Leaves

Vascular Bundles in Stems

Flower Parts

Monocots

Dicots

One cotyledon

Usually parallel

Scattered Multiples of three

Two cotyledons

Usually netlike

Arranged in ring

Multiples of four and five

The Flower : Female parts and function: The Pistil• 1.Ovule – develops the egg, turns into seed• 2. Ovary – forms the fruit, holds the egg, turns

into fruit• 3. Style – slender stalk that connects the

stigma to the ovary• 4. Stigma – receives the pollen

Male parts and function: The Stamen• 1. Anther – contains the pollen• 2. Filament – Supports the anther

stigma

style

ovaryovule

pistil

antherfilament stamen

Flower Parts

Flower Parts

Adaptations in plants:

• cacti – needle like leaves to prevent water loss and for protection

• venus fly trap – trap insects because it lives in nutrient depleted soil

• pitcher plant – leaves are made to trap insects

Life Span:

• annual – lives, reproduces, and dies in one year

• biennial – lives, reproduces, and dies two years

• perennial - lives, reproduces, and keeps growing year after year