I. Basic Organs of a Plant

A. Root

1. Functions in absorption of water and nutrients. It provides additional surface area, support, and storage.

2. Structure: has a root cap to protect the tip as it pushes through the soil.

B. Stem

1. Functions in transport between leaves and roots, as well as in storage, photosynthesis, and support.

2. Structure includes vascular tissue, nodes (where leaves originate),axillary bud (for leaf), lateral bud (for branches), apical bud allows stem to elongate vertically.

C. Leaf

1. Function in photosynthesis

2. Structure includes three parts in a complete leaf: blade, petiole, and stipules

D. Floral parts

1. Functions in reproduction

2. Structure includes Four main pats (in order of attachment)

a. Sepals (generally green. collectively: calyx)

b. Petals (generally colored. Collectively: corolla)

c. Stamens (male part) made of anther and filament

d. Pistil (female) ovary, style, and stigma (where pollen lands)

E. Fruit (ripened ovary wall)

1. Functions in seed distribution

2. Structure includes

F. Seed (Bean)

1. Functions in protecting and feeding embryo

2. Structure involves four parts protected by a seed coat

a. Cotyledons store food (Monocots: one cotyledon; dicots: two cotyledons)

b. Epicotyl: plumule (future stem)

c. Hypocotyl

d. Radicle

II. Kinds of plants

A. Non-vascular

1. mosses, liverworts

2. require water for reproduction; sperm must be able to swim to eggs

3. cannot grow very big because do not have vascular tissue

4. do not have true roots, stems, or leaves

B. Vascular

1. Ferns

a. have true roots, stems (rhizome: underground stem), and leaves (fronds)

b. require water for reproduction; sperm are flagellated

2. Gymnosperms (naked seeds)

a. Confers make up the most common order. reproduce using cones

b. pollen cones produce male microspores (released to be carried to female cones)

c. ovate cones produce female megaspores which are fertilized by pollen

d. seeds form after pollination and fertilization, drop out of cones

3. Angiosperms (flowering plants. seeds covered by fruit)

a. two major groups

1. monocots: seeds have one seed leaf

2. dicots: seeds have two seed leaves

b. stamen produces pollen grains which are transported to stigma

c. pistil receives pollen, protects zygote as it develops into an embryo

d. ovary ripens to produce fruit, protecting seed

III. Pollination

A. Pollination agents

1. Wind: gymnosperms, grasses, maples, ragweed

2. Living pollinators

a. insects

b. birds

B. Types of pollination

1. Self-pollination

2. Cross-pollination

IV. Tissues

A. Vascular tissues: used in transporting materials

1. Phloem: conducts sugars. usually transports materials downward from leaves.

2. Xylem: conducts water and raw materials. usually transports upward from roots.

B. Fundamental tissues

1. Parenchyma

a. mostly thin walled living cells used for storage. tissue is flexible, cells are large

b. found in most major parts of higher plants

c. parenchyma makes up most of the edible tissues in fruits and vegetables

2. Collenchyma

a. living cells with thicker walls than parenchyma cells

b. found just beneath epidermis

c. function in providing flexible support for organs

3. Sclerenchyma

a. cells have thick walls impregnated with lignin. usu. dead at maturity

b. Types:

1. Fibers found in roots, stems, leaves, fruits. used in textiles, ropes, string, canvas, etc.

2. Sclereids are randomly scattered throughout other tissues. example: stone cells in pears (give pears gritty texture), walnut shells

V. Root Systems

A. Tap root

1. generally found in dicots

2. one primary root develops, extending deep into ground

3. often used in storage, such as carrot or dandelion

B. Fibrous root

1. generally found in monocots

2. many hair-like roots develop, similar in diameter

VI. Leaves

A. Function: photosynthesis and transpiration (loss of water)

B. Structure

1. blade: flattened portion of leaf. shape varies according to species

a. simple: blade is not divided into leaflets

b. compound: blade divided into leaflets

1. pinnately compound: leaflets originate along different positions of long petiole (rachis)

2. palmately compound: leaflets originate to end of petiole

2. petiole: stalk that attaches blade to twig

3. stipules: protrusions (appendages) at the base of the leaf

C. Phyllotaxy (leaf arrangement)

1. opposite: two leaves attached at same node

2. alternate: one leaf at a node

3. whorled: three or more leaves at a node

D. Venation Patterns

1. parallel: large veins run parallel to each other (monocots such as grasses, corn)

2. palmate: series of main veins originate at petiole, then branch out

3. pinnate: one main vein (mid rib) has branching secondary veins.

E. Economic uses of leaves

1. food: cabbage, celery, parsley, lettuce....

2. spices, flavorings: thyme, oregano, peppermint....

3. fibers for ropes, twines

4. oils: citronella, camphor, petitgrain (used in soaps. from lavender or orange trees), eucalyptus

5. drugs: belladonna, digitalis, tobacco

6. insecticides: nicotine

7. waxes

8. aesthetic purposes

VII. Flowers

A. Structure: four whorls

1. Pedicel: stem/ stalk

a. receptacle

b. bracts

2. Perianth

a. sepals (collective: calyx): green part that surrounds bud, protects from invaders

b. petals (collective: corolla): generally colored portion to attract insects

3. Stamens (male reproductive parts produce microspores)

a. filament (stalk)

b. anther (sac)

4. Pistil (collectively called carpels) (female reproductive parts produce megaspore)

a. stigma: receives pollen

b. style: solid tissue tube that connects stigma to ovary

c. ovary: where fertilization occurs. later becomes fruit.

B. Variations in floral structures

1. Complete flowers have all four whorls

2. Incomplete flowers

a. perfect flowers are bisexual, containing stamen and carpels

b. imperfect flowers are unisexual, wither male or female

1. monoecious ("one house"): male flowers and female flowers found on same plant. ex.: corn, walnut, oak

2. dioecious ("two houses"): male plants and female plants. ex.: holly, persimmon

C. Numbers of floral parts

1. Monocots generally have parts in threes or multiples of threes

2. Dicots generally have parts in fives or multiples of fives

VII. Fruits

A. Function: seed dispersal mechanism of angiosperms

B. Origin: contains at least part of the ovary wall. Fruits are ripened ovaries

C. Development: after pollination and fertilization occur, ovary wall begins to grow as seed develops

D. Kinds of fruits

1. Simple fruits develop from the ovary of one pistil.

a. Simple dry fruits

1. dehiscent (dry at maturity, opening on their own)

a. follicle: splits on one side only. ex: milkweed.

b. capsule: splits on many sides. ex: poppy, horse chestnut

c. legume: splits along two sides. ex: peas, beans, peanut

d. silique: splits along two sides, seeds borne on partition. ex: mustards (broccoli, cabbage)

2. indehiscent (dry at maturity, do not open on their own)

a. achene: seed attached to husk at base, easily separated. ex: sunflowers

b. grain: seed coat fused to husk, cannot be separated. ex: corn, wheat

c. samara: has wings, one or two seeds. ex: maple, ash, elm

d. nut: one-seeded fruit with thick husk. ex: acorn, hazelnuts, hickory nut.

b. Simple fleshy fruits

1. pome: most of the flesh comes from the receptacle. ex: apples, pears, coconut, walnut

2. berry: contain several seeds; very fleshy. ex: tomato, pepper, grape, blueberry, pumpkin family, citrus fruit, banana

3. drupe: fleshy fruit with one seed. ex: cherry, peach, plum

2. Aggregate fruits: from single flower with many pistils. fruit is clustered on a single receptacle. ex: raspberry, strawberry, blackberry.

3. Multiple fruits: from several flowers in a single inflorescence. ex: pineapple, fig.

VIII. Seed

A. Structure: Dormant embryo with protected food supply

B. Dispersal

1. Wind: seeds light, small. dandelion, maple

2. Water: have inflated sacs to allow for floating. sedges

3. Animal: eaten (fruits, nuts), stick to fur (burrs)

4. Mechanical agents

5. Reason for dispersal: increase survival rate, decrease competition

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