Transcript Unit 2 Plant Science PowerPoint

Unit II – Plant Science
The Importance of Plants
Benefits of Plants
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Plants are essential to the survival of human
beings.
Plants provide biological, physical, and
emotional benefits.
 Biological
 Plants convert CO2 to O2 by
photosynthesis
 Provide food
Benefits of Plants
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Physical
 Provide materials for shelter
 Provide materials for clothing
 Provide shade, cooling, and wind control
 Reduce wind and water erosion
 Provide energy sources
 Provide habitat for wildlife
Benefits of Plants
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Emotional
 Provide beauty
from landscapes
and individual
specimens
 Provide an
enjoyable hobby
 Provide a relaxing
effect
Plant Science Areas*
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Four areas of science that are closely related to the
study of plants
 Botany* the science of plants and consists of
anatomy, ecology, physiology, and taxonomy
 Horticulture* includes producing, processing, and
marketing fruits, vegetables, flowers, ornamental
shrubs, and trees; nursery and landscaping; and
turf management
 Agronomy* the study of field crops and soil
management
 Forestry* the science of managing trees for
lumber, paper, and other wood products
Plant Science
Plant Parts and Processes
Main Parts of
a Plant
•Plants are made of four
main parts: roots, stems,
leaves, and flowers.
•Each part is essential to
the growth or
reproduction of the plant.
•Roots*
•Absorb water and
minerals from the soil
•Anchor the plant
•Food storage area
Main Parts of
a Plant
•Stems
•Supports the plant’s
leaves and flowers
• Leaves*
•Major producer of food
for the plant (through
photosynthesis)
•Food storage area
•Site of respiration and
transpiration
•Flower*
•Site of sexual
propagation
•Source of fruit and seed
•Attracts pollinators
Photosynthesis vs. Respiration*
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Photosynthesis is the
process by which plants
produce their own food.
Sunlight (Chlorophyll)
+ Water + Carbon
Dioxide = Energy
(Sugars)+ Oxygen
Respiration is the
process by which plants
take in Oxygen and
release carbon dioxide.
How do plants reproduce?*
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Sexually
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Sexual propagation occurs within the flower as a
result of pollination
This produces fruit and seeds
Asexually
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Asexual propagation uses vegetative parts
Asexual techniques can produce new plants from
leaves, stems, and roots, depending on the plant
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When you finish this, you should be able to:
Understand plant reproduction, the importance of flowers,
the pollination process, and the relationship between
plants and animals in reproduction.
Identify at least three ways plants are able to reproduce.
Demonstrate a propagation technique.
Identify the parts of flowers.
Pay special attention to these key ideas:
Flowers are made up of different parts.
Flowers need to be pollinated in order to make seeds.
Flowers attract insects and animals that aid in the
pollination process.
Plant structures can be used to start new plants.
Flower Parts
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Flowers are important in making seeds.
Flowers can be made up of different parts,
but there are some parts that are basic
equipment. The main flower parts are the
male part called the stamen and the female
part called the pistil.
The Stamen
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The stamen has two
parts: anthers and
filaments. The anthers
carry the pollen. These
are generally yellow in
color. Anthers are held
up by a thread-like part
called a filament.
The Pistil
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The pistil has three
parts: stigma, style, and
ovary. The stigma is the
sticky surface at the top
of the pistil; it traps and
holds the pollen. The
style is the tube-like
structure that holds up
the stigma. The style
leads down to the ovary
that contains the ovules.
Other Parts
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Other parts of the flower
that are important are the
petals and sepals. Petals
attract pollinators and are
usually the reason why we
buy and enjoy flowers. The
sepals are the green petallike parts at the base of the
flower. Sepals help protect
the developing bud.
Perfect vs. Imperfect
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Flowers can have either all male parts, all
female parts, or a combination. Flowers
with all male or all female parts are called
imperfect (cucumbers, pumpkin and
melons). Flowers that have both male and
female parts are called perfect (roses, lilies,
dandelion).
Pollination
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When pollination occurs,
pollen moves from the male
parts to the female parts.
Pollen grains land on the
stigma and a tiny tube grows
from it and down the style
into the ovary. The fertilized
ovule becomes the seed and
the ovary becomes the fruit.
The Fruit
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When a plant flowers and produces seeds, it also produces
something else we all like -- fruit. As you learned, when the
ovary ripens, it swells and forms a protective covering
around the seeds. This protective covering, or fruit, often
finds its way on top of cereal, ice cream, a salad, or just a
tasty snack.
Pollination
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Since flowers can't move, they need to be
able to attract pollinators or be built so that
wind is able to pollinate them. Flowers
attract pollinators like bees, butterflies,
insects, and birds with sweet nectar, bright
colors, and shapes and structures. Some
flowers open at special times to attract
pollinators such as night blooming plants
that are pollinated by bats.
Asexual Propagation
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Plants from parts is a form of asexual or vegetative
propagation. This process is sometimes called cloning
because every new plant is exactly like the parent.
One type of cloning uses cuttings--parts of plants that
grow into new plants. Both stems and leaves can be
used as cuttings. Another kind of cloning is grafting-the joining together of two plants into one. Other
kinds of cloning use bulbs or tubers--underground
parts that make new plants.
There are several common asexual
propagation methods
There are several common asexual
propagation methods
Asexual Propagation
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There are four main reasons for using asexual
propagation.
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Some plants do not produce seed or seeds are
difficult to germinate
It is usually a faster process than seeding
It is more economical
Functions of the parts of the
flowers?*
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Petals
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Pistil
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Female structure of the flower
Site of fruit and seed formation
Contains the stigma, style, and ovary
Sepal
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Attract insects for pollination
Protects the flower in the early stages
Stamen
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Male structure of the flower
Produces pollen
Contains the anther and filament
Germination*
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Germination is the beginning or plant growth as seen
by the sprouting of the seed
The seed is in a dormant, or resting, stage with a
supply of food and a protective seed coat until the
requirements for germination are met
The following are needed for a seed to germinate:
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Favorable temperature that varies by species
Sufficient moisture
Air
Presence or absence of light (depends on plant species)
Annuals vs. Biennials vs. Perennials*
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Annuals are plants that complete their life
cycle (grows, flowers, produces seed, and dies)
in one year
Biennials are plants that grow during one year
and flower, produce seed and die during the
next year. They live for two years
Perennials are plants that live for more than
two years. They can grow year after year
without replanting.
Monocots vs. Dicots*
Process of a seed growing to plant.
Process of a seed growing to plant.
Plant Science
Plant Care Requirements
What are the factors affecting plant
growth?
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*Water
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Essential for photosynthesis
Maintains cell shape
Enables nutrients to be absorbed and transported
throughout the plant
*Growing medium
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Provides support for the roots
Allows water and air filtration and movement
Stores needed nutrients
What are the factors affecting plant
growth?
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*Nutrients (fertilizer) – 16 nutrients essential for
plant growth
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*Light
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(Mg Ca N S P K, Cu Zn Fe Mo Mn Cl B, C H O)
Plants need different levels of light intensity
Light is required for photosynthesis
*Temperature
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Plants differ greatly in their tolerance for hot and cold
temperatures
Extremes in temperature can cause slow growth, fruit or
flower damage, or death of the plant
What’s in a bag of fertilizer?
Sample Label
1.The Guaranteed Analysis shows the percentages
of nutrients in a fertilizer. The three numbers always
stated on the front of the bag indicate the percentage of
N, P, and K. The rest of the analysis is listed below as
items 2, 3, and 4.
2.This states the total nitrogen and itemizes the
percentages from a variety of nitrogen types. It also
details the percentage of phosphorus (called “available
phosphate”) and the percentage of potassium (called
“soluble potash”) in the bag.
3.This states the amount of iron contained in the
fertilizer. Iron is important to help lawns achieve a deep
green color. If other nutrients such as magnesium or
calcium are included, they will also be listed here.
4.This states from what sources the ingredients in
the bag originate. Most are long names that won’t
mean much unless you know chemistry.
What care should be provided for
indoor plants?
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*Provide proper water
 Use a well-drained growing
medium
 Water plants as needed
 Water thoroughly at every
watering
*Control humidity levels
*Maintain appropriate
temperature range
*Maintain appropriate light levels
*Fertilize the growing medium as
needed
*Provide appropriate pinching
and pruning
 Pinch or prune dead/damaged
leaves and branches
 Pinch or prune to maintain
plant shape
What care should be provided for
outdoor plants*?
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Watering is usually only required during dry periods
Grow in areas where they are adapted
Select tolerant plants for locations where pollution
can be a problem
Fertilizer is generally only needed once per year
Prune occasionally to remove dead and damaged
leaves and branches
Prune to maintain the plant’s natural shape, when
required
Rules of Proper Watering
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Use a well-drained growing
medium
 The medium should be
porous yet retain water
Water plants as needed
 Observe the color of the
medium
 Test for moisture by
touch
Water thoroughly at every
watering
 Water should flow out the
bottom of the container
Plant Science
The Growing Medium
What is soil?
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*Soil is the naturally occurring top layer of the
earth’s surface that provides food, water, air,
and support for plant life.
Soil is a natural resource that humans depend
on for food, clothing, and materials for shelter.
Soil is composed of a great amount of life.
Scientists agree that there is more life below
the surface of the earth than there is above it.
*Soil is not dirt! Dirt is misplaced soil.
What are the components of soil?
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The ideal soil contains the following components:
 *45% mineral matter – inorganic (not from plants or
animals) and varies in size
 Sand – largest particles
 Silt – medium-size particles
 Clay – smallest particles
 *5% organic matter – originates from a living source,
usually a plant or animal
 25% water
 25% air
Ideal Soil Components
Soil Particle Sizes
What is a growing medium?
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*Growing medium (singular) or growing
media (plural) are the materials in which the
roots of plants grow.
The growing medium supports, or anchors, the
plant in place, even after watering.
The growing medium must retain sufficient
moisture, yet be porous enough to allow excess
water to drain.
What is a soilless mix and where is it
used?
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*A soilless mix is a medium that contains no soil.
Soilless mixes contain various combinations of the
following materials.
 Perlite – gray-white material of volcanic origin
used to improve aeration
 Vermiculite – heat-treated mica (a very thin,
layered mineral) with a high moisture-holding
capacity
 Peat moss – partially decomposed vegetation with
a high moisture-holding capacity
 Tree bark – usually the bark of fir, pine, or cedar
as a source of organic matter
What is hydroponics?
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*Hydroponics is a method of growing plants in water
(nutrient solution) rather than soil.
*This technique is used to grow high-value crops in
greenhouses, especially during the winter.
Some hydroponic systems use sand, gravel,
rockwool, pealite, or sawdust rather than soil.
Bare root systems mist the roots of plants at regular
intervals with a nutrient solution, use shallow pools
with plants floating on the surface, or use
recirculating streams of nutrient solutions.
Aquarium Hydroponic System