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Classification of Plants
(Ch. 22)
The 3 major characteristics that make an organism a plant are:
 Multicellular eukaryote
 Cell walls with cellulose
 Carry out photosynthesis
Plants most likely evolved from:
Multicellular green algae
What were some challenges that plants had to overcome as they moved to land?
 Drying out in the sun
 Conserving water
 Reproduction without water
The 4 groups of plants are:
1. __Mosses__________
2. ___Ferns___________
3. __Gymnosperms (cone-bearing)_
4. ___Angiosperms (flowering)___
The 3 features used to group the plants are:
1. __water-conducting tissues______
2. ____seeds___________________
3. ____flowers_____________
For each group of plants, identify the major characteristic of that group. Give examples.
Group
Vascular or
Nonvascular
Seedless
or Seeds
Examples
Bryophytes
Non-vascular
no seed
moss; liverwort
Ferns
Vascular
no seed
horsetail ferns
Gymnosperms
Vascular
seeds
conifers; cycads
Angiosperms
Vascular
seeds
flowering plants
Evolutionary Relationships of Plants
(diagram p. 554)
Flowering
PlantsAngiosperms
ConifersGymnosperms
Flowers
Ferns
Seeds
Mosses
Vascular
System
Multicellular
green algae
Parts of Plants
(Ch. 23)
What are the 3 main organs and their functions?
 Roots- absorb water and nutrients
 Leaves – Photosynthetic
 Stems-support; connect root + leaves; carry H2O + nutrients
Tissues: name the 3 main types and their functions:
 Dermal: outer covering of plant
o cuticule: thick waxy covering, conserves water;
o root hairs: small cells on roots, increase survace area for water absorption
 Vascular: transport system used to move water and nutrients through the plant
xylem: transports water

phloem: transports nutrients + carbs from photosynthesis
Ground tissue-cells between dermal and vascular tissue
Roots:
Used for:
1) Absorption of minerals and water from the soil.
2) Storage of starches (vegetables)
3) Anchor to ground
4) 2 main types of roots:
• taproot—grow long and deep to reach water below the surface.
Ex. Carrots, radishes
 fibrous—branched root system that grows close to the surface helps prevent soil from
being washed away by rain.
*Plants can have taproots, fibrous roots or both*
5) Apical Meristem: area of root where cell division and growth occurs.
Stems:
Function: produce leaves, branches, and flowers; used for support and transport of substances between leaves
and roots.
Leaves:
Function: Absorb light and carry out photosynthesis
Special structures
• Stomata—opening in leaf to allow exchange of O2, CO2 and water vapor
• Guard cell —regulates opening of the stomata and respond to conditions in the environment (wind,
temperature) to maintain homeostasis within leaf.
Underside of leaf
Photosynthesis: write the equation below. Explain how the following structures influence photosynthesis
Equation: CO2 + H2O + Light  C6H12O6 + O2
 Xylem: transports water needed for reaction to occur.
 Phloem: transports glucose from leaves to roots for storage.
 Stomata & Guard Cells: regulates the amount of CO2 gases & H2O needed for photosynthesis to occur.
 Leaf: contains chloroplasts, chlorophyll, + enzymes needed for photosynthesis
Transpiration
• loss of water through stomata
• When water is abundant, it flows from roots to leaves and guard cells respond by opening stomata to
release excess water
• When water is scarce, guard cells respond by closing stomata to limit transpiration
• High transpiration rates can lead to wilting.
http://youtu.be/mc9gUm1mMzc
Turgor Pressure:
 Turgor pressure is the pressure of a plant cell’s contents against the cell wall. This gives the plant its
rigid structure.
 What are some conditions which could cause Turgor Pressure to decrease, thus causing the plant to wilt?
Plant dehydration: the vacuole loses water, causing turgor pressure to decrease and the plant will wilt
Describe a monocot: 1 seed leaf; parallel veins; flower multiples of 3; Fibrous roots
Describe a dicot: 2 seed leaves; branched veins; flower multiples of 4 or 5, tap root
Reproduction
(Ch. 24)
Define pollen grain: male sex cell
In gymnosperms, the male cone is called the _pollen_ cone and the female cone is called the _seed__ cone.
In angiosperms, the reproductive organs are the __flowers__.
The 4 kinds of specialized leaves: 1. __Sepals_
2. _Petals___ 3. __Carpel/Pistil (female)_ 4. __Stamens (male)_
Seeds
Define a fruit: ripened ovary containing angiosperm seeds. Fruit protects seed, helps in dispersal.
Give 10 examples of fruits: apple, pear, beans, grape, peach, pea, strawberry, tomato, corn, cucumber, grape,
pear
Compare and give examples of fleshy and dry fruit:
Fleshy: apple
Dry: maple, ash
Name 3 methods of seed dispersal and give examples:

Animals – insects, birds, bats + other mammals

Wind – maple, dandelion

Water
Germination
Define germination: early growth stage of the plant embryo
Describe the 3 steps of germination:
1. absorb water
2. food – storing tissues swell, crack open seed coat
3. young root emerges, begins to grow
Growth
(Ch. 25)
What is the role of hormones? Chemical substances that control:
1- pattern of growth and development.
2- plant’s response to environmental conditions
For each hormone listed below, give the effect that it has on the plant:




auxin (3): growth- branching; phototropism- bend toward light; gravitropism – root growth downward
cytokinins (2): stimulate cell division; growth of lateral buds; cause dormant seeds to sprout
gibberellins (1): growth hormone-dramatic increase in size especially in stems and fruit
ethylene (1): stimulates fruit to ripen
Responses
For each type of response listed, explain and give an example.
Tropism response to external stimuli


Gravitropism: response to gravity. Shoots grow up-against gravity. Roots grow down- with force of
gravity
Phototropism response to light

Thigmotropism response to touch: growing tip grows + twist
Around object; stunted growth

Photoperiodism: response to amt of day light (seasonal changes)

winter dormancy: plant growth + activity decrease or stops.

leaf abscission: layer of cells forms at petiole; seals leaf off from plant’s vascular system
Adaptations
(Ch. 25)
Name 3 ways plants have adapted to life in the water:


Air-filled spaces in tissues, allow for uptake + diffusion of oxygen
Seeds that float in water

Bald cypress- knees protrude above water, bring O2 to roots
Name 1 way plants have adapted to salty conditions:

Leaves have special cells that pump salt out at tissues and onto leaf surface  washed off by rain
Name 3 ways desert plants have adapted:

Extensive roots to capture water, w/ many root hairs (cacti)

Leaves become spines

Thick green stems- photosynthesis, store H2O, seeds dormant for years germinate with rain.
Name 2 ways plants have adapted to poor soil:


Carnivorous- pitcher plant, Venus fly trap (nutrient poor/nitrogen poor soil)
Parasitic – extract water and nutrients directly
(examples-mistletoe)
Name 1 way plants have adapted to grow on other plants:

Epiphytes- grow directly on bodies of other plants, get water from rain, make own food. Ex: Spanish
moss
Name 1 way that plants have adapted to help fight insects:

Manufacture compounds that have effect on insects (poisons)
Insect hormones-prevent insect from reproducing
Flower diagram:
(p. 612)
Stamens
Anther
Filament
Stigma Pistil/Carpal
Style
Ovary
Petal
Ovules
Sepal
Stamen ♂ : anther + filament
Carpal or pistil ♀ : stigma + style