Download BIODIVERSITY OF PLANTS

Flower Anatomy
STAMEN: The male reproductive
structure.
PISTAL: The female reproductive
structure.
Stigma
Captures the pollen.
Anther
Produces the pollen grains
which are the male sex cells.
Style
Moves the pollen
to the ovary.
Filament
Supports the anther.
Ovary
Contains the eggs.
Later becomes the fruit.
Fertilized eggs become seeds.
OVERVIEW OF PLANT STRUCTURE
Plants are:
 KINGDOM - Plantae
 Multicellular
 Usually autotrophic (make their own energy by photosynthesis)
 Sexual and Asexual reproducers
 Mostly terrestrial (land) and some aquatic (water)
Plants can be placed in 2 categories:
1. SEED PLANTS
2. NON SEED PLANTS
Seed Plant / Non Seed Plant Concept Map
SEED PLANTS
SEEDLESS PLANTS
GYMNOSPERMS
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PRODUCE SEEDS
THAT ARE NOT
ENCLOSED
Seeds that are
exposed on the
surface of cones;
Includes conifers
such as pines,
firs, spruce and
cedar trees
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ANGIOSPERMS
Produce enclosed
SEEDS contained
in fruit
Vascular;
Reproduce using
flowers,
called
FLOWERING
PLANTS
MOST
ABUNDANT
PLANT ON
EARTH
MONOCOTS

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Produce seeds in which
the embryo has only 1
cotyledon or seed leaf
(structure that helps
nourish the plant)
Examples: corn, onions,
orchids
MOSSES
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NON SEED
PLANTS
WITHOUT A
VASCULAR
SYSTEM
Dependent on
diffusion and
osmosis for
nutrients;
No roots;
Rhizoids (rootlike structures)
DICOTS

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Produce seeds in which
the embryo has 2
cotyledon or seed leaf
Examples: dandelions,
maple trees
CHARACTERISTICS OF MONOCOTS AND DICOTS
FERNS

NON SEED
PLANTS WITH A
VASCULAR
SYSTEM
PLANT TISSUES
There are 4 types of plant tissue:
1. Meristematic Tissue
2. Dermal Tissue
3. Ground Tissue
4. Vascular Tissue
MERISTEMATIC TISSUE

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Cells divided by mitosis;
These cells differentiate into other plant cell types;
1) Apical Meristems
 Found at the tips of roots and shoots
 Responsible for primary growth (lengthening shoots and roots)
2) Lateral Meristems (Cambium)
 Cylindrical regions which increase the diameter of roots and shoots
(secondary growth)
3) Vascular Cambium
 Produces the cells for new xylem (water) and phloem (food)
DERMAL TISSUE

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Outermost cell layers
Function:
o protection from cuts;
o microorganism invasion;
o water loss;
Examples
o Leaves and stems may produce wax (prevent water loss) or fine hairs or
painful irritants (to discourage herbivores)
o Epidermal root tissues develop root hairs to increase water and nutrient
absorption
o Woody plants produce bark for further protection (bark consists of dead
cells)
GROUND TISSUE

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All internal cells except vascular tissues
Function
o Storage
o Support
o Photosynthesis
Examples
o Fleshy portion of apples, pears, potatoes
VASCULAR TISSUE

For transport of substances in the plants
Xylem
o Transports water and dissolved minerals from roots to the rest of the
plant
o These cells die at maturity and become hollow
o Appearance – thick walls, may be long and thin or shorter with open ends
o When arranged end to end they make continuous tubes for transport
o Wood is 100% xylem tissue  good support for trees
Phloem
o Transports sugar and other nutrients from the leaves (site of
photosynthesis) to the rest of the plant
o Living cells
o Sieve tube element
 Long thin cells with pores at the ends of their cell walls
 No nuclei, mitochondria or vacuoles
 Arranged end to end to form tubes
o Companion cells
 Found beside sieve-tube elements
 Have all the cell organelles that the sieve-tube is lacking
 Control the functions of the sieve tube
DIAGRAMS OF THE VASCULAR TISSUE
ROOTS
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Usually below the ground
Serves 5 functions
o Anchor the plant to the ground
o Absorbs water and minerals
o Store extra sugar during photosynthesis
o Transport water, sugar, minerals and hormones to the remainder of the
plant
o Produces some hormones

Edible roots include:
o Carrots, radishes, sweet potatoes
2 forms:
1. Tap root
o Large tapering main root
o Example - carrot
2. Fibrous root
o Many smaller roots of equal size that grow out of the bottom of the
plant
o Example – grass
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ROOT AND SHOOT SYSTEM
FLOWERING PLANTS CONSIST OF 2 MAJOR REGIONS:
THE ROOT SYSTEM
 Usually below the ground
 Serves 5 functions
o Anchor the plant to the ground
o Absorbs water and minerals
o Store extra sugar during photosynthesis
o Transport water, sugar, minerals and hormones to the remainder of
the plant
o Produces some hormones
THE SHOOT SYSTEM
 Usually found above the ground
 Consists of stems, leaves, buds, flowers and fruits
 Serves 4 functions
o Photosynthesis
o Transport of materials between leaves, flowers, fruit and roots
o Reproduction
o Production of some hormones
ROOT GROWTH AND DIFFERENTIATION
Root Cap
o Protective layer of cells at the tip of the root
Apical Meristem
Zone of Elongation
o Newly divided cells from the apical meristem increase
in length
Zone of Maturation
o Root cells differentiate and mature; region with root
hairs
STEMS
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Provide support for the above ground portion of the plant;
Connect roots with the remainder of the plant;
Store water and food;
Transportation system – xylem and phloem are located in the stems
Examples – potatoes

2 types
1. Woody
o Stems are hard and not easy to bend; strong
o Composed of dead xylem tissue
2. Non-woody
o Soft and bend easily; weak
o Height limits
Vascular Cambium and
Phloem Cells
New Xylem matures into
wood; Annual Ring is the
amount of xylem produced in 1
year
LEAVES

Green leaves (chlorophyll) are the site of photosynthesis
Veins – an extension of the vascular tissue
from the stem
Node – the attachment site of the leaf to the
stem
Internode – the space between
nodes on the stem
SIMPLE AND COMPOUND LEAVES
Simple Leaf – continuous undivided
blade
Compound Leaf – leaf that is divided
into 2 or more leaflet
successive
LEAF STRUCTURE
Epidermal Cells
 1 cell layer of cells covering the upper and lower surfaces of the leaf blade
Palisade Mesophyll Layer
 Cells at right angle to the leaf surface; rich in chloroplasts; site of
photosynthesis
Spongy Mesophyll Layer
 Loosely packed cells with large air spaces; air spaces allow for efficient gas
exchange; site of photosynthesis; leaf veins run through this layer
Stoma
 A small opening in the surface of the leaf which permits the exchange of gases
Transpiration – process of water loss through evaporation out of the leaf
when the stoma are open
Guard Cells
 Control the opening and closing of the stoma; a pair of crescent shaped cells
that surround the pore opening
SEEDS AND FRUIT
Most of the species we eat are angiosperms.
Most commonly the seeds and fruit are used to feed the 6 billion (+) people on the
planet.
SEEDS
The worlds’ 3 most important crops are:
1. Wheat
2. Corn
3. Rice
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Other important crops are soybeans or other beans.
The edible portion of these crops are the seeds
The seeds of these plants are high in protein, carbohydrates and fibre.
FRUIT
 Structure that develops in the ovary of a pollinated angiosperm
 Fruits help the plant spread its seeds
o Maple keys, dandelion fluff are examples of fruits with a form that helps
them spread
o Consumed in animals and pass through the digestive tract unharmed and
are deposited in another location
 Many vegetables are actually fruits – cucumbers, pumpkin, tomatoes, zucchini,
squash
 Other common fruits include bananas, mangoes, apples
SEEDS AND FRUIT
Most of the species we eat are angiosperms.
Most commonly the seeds and fruit are used to feed the 7 billion (+) people on the
planet.
SEEDS
The worlds’ 3 most important crops are:
1. Wheat
2. Corn
3. Rice



Other important crops are soybeans or other beans.
The edible portion of these crops are the seeds
The seeds of these plants are high in protein, carbohydrates and fibre.
FRUIT
 Structure that develops in the ovary of a pollinated angiosperm
 Fruits help the plant spread its seeds
o Maple keys, dandelion fluff are examples of fruits with a form that helps
them spread
o Consumed in animals and pass through the digestive tract unharmed and
are deposited in another location
 Many vegetables are actually fruits – cucumbers, pumpkin, tomatoes, zucchini,
squash
 Other common fruits include bananas, mangoes, apples
POLLINATION
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Process by which pollen is moved from the anther (portion of male reproductive
structure – STAMEN) to the female egg cells and fertilizes these cells.
Some plants can fertilize themselves and others need pollen from a different
plant.
Some plants even have separate male plants and female plants.
The pollen is able to travel between plants in many different ways, wind, animals,
birds, and insects (BEES).
Once the eggs are fertilized they become seeds.
The petals fall and in some species the ovary develops into the fruit.
CONTROL OF PLANT DEVELOPMENT

Plant development involves growth (increase in the number and size of cells) and
differentiation (change in the form or function of the cells)
INTERNAL FACTORS
PLANT GROWTH REGULATOR (PLANT HORMONES)
 Chemical produced by plant cells that regulates growth and development
 5 common plant hormones:
1. AUXINS
 Promotes the elongation cells
 Stimulate the growth and ripening of fruit
 Inhibit dropping of fruit and leaves
2. GIBBERELLINS
 Promote cell division and elongation
 Cause fruit to enlarge
3. CYTOKININS
 Stimulate cell division and leaf growth
 Extend the life of cut flowers
4. ABSCISIC ACID
 inhibitor of growth
 coordinate stress response
 induce closing of stoma – reduce rate of transpiration
5. ETHYLENE
 Controls timing of flower death, fruit ripening, leaf and fruit loss
 Associated with the colour change and sweetness of fruit
EXTERNAL FACTORS
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Plants must be able to respond to external factors such as temperature, the
amount of light and amount of moisture
Changes in these factors may result in changes in the amounts of plant growth
regulators
There are 2 examples of environmental responses:
1. TROPISM
2. PHOTOPERIODISM
TROPISM
 Changes in growth pattern or movement in response to directional environmental
stimuli
o Thigmotropism
 Response to touch
o Phototropism
 Response to light
 Example – plant stretches towards light
o Gravitropism
 Response to gravity
 Allows plants to orientate themselves appropriately to
their environment
PHOTOPERIODISM
 Plant development that varies with the amount and quality of light
 Amount of daylight triggers changes that are linked to seasonal changes and the
reproductive cycle of the plant
PEST CONTROL
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ALWAYS COMPETITION AFFECTING THE GROWTH OF PLANTS
Host of Fungi, insects and other organisms feed on and in plants
Look for ways to eliminate or control these competitors;
Effective pest control is required
PESTICIDES
 A chemical used to kill pests
o Insecticides – kill insects
o Fungicides – kills fungus
o Herbicides – kills plants (weeds)
 Broad Spectrum Pesticides
o Kills a large variety of species
 Selective Pesticides
o Kills only limited or specific species
PESTICIDE SAFETY
 Pesticides are regulated to protect human health and natural environments
 Legislation governs the sale, use and storage of pesticides;
 Risks on human health have led to the elimination of a number of pesticides
BIOACCUMULATION
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PROCESS BY WHICH THE CONCENTRATION OF A COMPOUND
INCREASES THROUGH THE FOOD CHAIN
THE CHEMICALS DO NOT BREAK DOWN SO THEY PERSIST IN THE
ENVIRONMENT
INTEGRATED PEST MANAGEMENT
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A PEST MANAGEMENT STRATEGY THAT USES A COMBINATION OF
CAREFUL MONITORING, NATURAL BIOLOGICAL CONTROLS AND
LIMITED APPLICATIONS OF SYNTHETIC PESTICIDES
All pests have natural predators
o Lady bugs
o Wasps
WHY DO HUMANS GROW PLANTS?
1. FOOD
 corn, tomatoes
 grains – corn, rice, beans
 herbs – basil, oregano
2. MEDICINE
 Codeine
o analgesic (pain killer)
o made from the plant Papaver somniferum
3. PULP AND PAPER
 937 tons of paper is used each day (not including food products such as
wrappers)
4. FUEL
 Source of heat in wood burning stoves, fireplaces
5. CONSTRUCTION MATERIALS
 Wood is the most common building material – Homes, furniture, etc.
6. CLOTHING
 Fibres / Fabric – cotton, rayon
7. DECORATION
 Annuals - Live only for 1 growing period
 Biennials - Live for 2 growing periods
 Perennial- Long living, live for a number of growing period
WORKING WITH PLANTS
Plants are an important part of our lives.
There are many careers associated with the growing and caring of plants.
Arboriculture
 The cultivation of trees and shrubs
 Arborists – people who work with Arboriculture
Forestry Technology
 One of Canada’s largest industries
 Measure forest resources
 Forest fires, Firefighting methods, Prescribed burns
Horticulture
 The science and art of cultivating fruits, vegetables, flowers and ornamental
plants
 Work in nurseries, greenhouses, garden centres, landscaping firms
Hydroponics
 A technique for growing plants in solution rather than soil
 Common in commercial greenhouses because it reduces pathogens and pests
that live in soil
Turf Management
 Growing and maintaining lawns
 Golf courses, sports fields, public parks, private residences