Transcript Prentice Hall Biology - Jamestown School District

Plant Diversity
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Section:
Section Outline
Section 22-2
What is a Plant?
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•
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Section:
Multicellular
Eukaryotic
Have cell walls
Carry out photosynthesis using the green pigments
- chlorophyll a, and chlorophyll b
Section Outline
Section 22-3
What Plants Need to Survive
• Sunlight - plants use sunlight to carry out
photosynthesis. Plants display adaptations shaped by
the need to gather
• Water and Minerals - all cells need a constant supply
of water. Water is a raw material for photosynthesis,
so when the sun is shining water gets used up
• Gas Exchange - plants require oxygen for cellular
respiration and need carbon dioxide to carry out
photosynthesis.
- plants must exchange these gasses with the
atmosphere without losing excessive amounts of
water from evaporation
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Section:
Section Outline
Section 22-3
Early Plants
• For most of Earth’s history, plants did not exist
• Life was concentrated in the oceans - algae and
photosynthetic prokaryotes added oxygen to the
atmosphere.
• When plants appeared much of the existing life on
Earth changed.
• As early plants colonized land, they changed the
environment in ways that made it possible for other
organisms to develop.
• New ecosystems emerged and organic matter began
to form soil
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Section:
Figure 22–6 A Cladogram of Plant Groups
Section 22-1
Flowering
plants
Cone-bearing
plants
Ferns and
their relatives
Flowers; Seeds
Enclosed in Fruit
Mosses and
their relatives
Seeds
Water-Conducting
(Vascular) Tissue
Green algae
ancestor
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Section:
Figure 22-7 The Diversity of Plants
Section 22-1
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Section:
Section Outline
Section 22-3
Bryophytes
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Mosses, liverworts, hornworts
Bryophytes lifecycles depend on water for reproduction
Lack vascular tissue - water is drawn up only by osmosis
Mosses are most common, they are most abundant in
areas with water - swamps and bogs, near streams, and
in rain forests.
• Mosses are the most abundant plants in the polar region
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Section:
The Structure of a Moss
Section 22-2
Capsule
Sporophyte
Stalk
Stemlike
structure
Leaflike
structure
Rhizoid
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Section:
Gametophyte
Evolution of vascular tissue
•Xylem - the transport system that
carries water up from the roots
•Phloem - transports solutions of
nutrients and carbohydrates produced
by photosynthesis
•With the evolution of vascular tissues
what challenges could early plants
overcome?
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Section:
Ferns and their relatives
•Seedless vascular plants
•Have true roots, stems, and leaves
•Club Mosses, horsetails, and ferns
•Ferns reproduce using spores
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Section:
Section Outline
Section 22-3
Seed Plants
• Reproduction free from water
• Adaptations that allow plants to reproduce without water
include flowers or cones, the transfer of sperm by
pollination, and the protection of embryos in seeds
• Seed plants are divided into two groups.
• Gymnosperms - bear their seeds on cones
• Angiosperms - flowering plants - bear their seeds in a layer
of tissue to protect the seeds (Fruit)
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Section:
Compare/Contrast Table
Section 22-4
Comparing Features of Seed Plants
Feature
Gymnosperms
Angiosperms
Seeds
Bear their seeds on cones
Bear their seeds within
flowers
Reproduction
Can reproduce without
water; male gametophytes
are contained in pollen
grains; fertilization occurs
by pollination
Can reproduce without
water; male gametophytes
are contained in pollen
grains; fertilization occurs
by pollination
Examples
Conifers, cycads, ginkgoes,
gnetophytes
Grasses, flowering trees
and shrubs, wildflowers,
cultivated flowers
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Section:
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Section:
Figure 22–19 The Structure of a Seed
Section 22-4
Seed coat
Seed
Embryo
Wing
B
Stored
food supply
A
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Section:
Section Outline
Section 22-5
22–5
Angiosperms—Flowering Plants
A. Flowers and Fruits
B. Diversity of Angiosperms
1. Monocots and Dicots
2. Woody and Herbaceous Plants
3. Annuals, Biennials, and Perennials
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Section:
Concept Map
Section 22-5
Plants
are categorized as
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Section:
Annuals
Biennials
Perennials
that complete
their life cycle in
that complete
their life cycle in
that complete
their life cycle in
1 growing
season
2 years
More than
2 years
Figure 22–25 Comparison of
Monocots and Dicots
Section 22-5
Monocots
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Section:
Dicots
Seeds
Single
cotyledon
Two
cotyledons
Leaves
Parallel
veins
Branched
veins
Flowers
Floral parts
often in
multiples of 3
Floral parts often
in multiples
of 4 or 5
Stems
Vascular
bundles
scattered
throughout stem
Vascular
bundles
arranged in
a ring
Roots
Fibrous roots
Taproot
Go Online
The latest discoveries in plants
Bryophyte activity
Career links on botanical illustrators
Interactive test
For links on classifying plants, go to www.SciLinks.org and enter the
Web Code as follows: cbn-7221.
For links on seedless vascular plants, go to www.SciLinks.org and enter
the Web Code as follows: cbn-7223.
For links on seed plants, go to www.SciLinks.org and enter the Web
Code as follows: cbn-7224.
Interest Grabber Answers
1. With your partner, list five items you use daily that are byproducts of plants.
Student lists will vary, but should include some of the following items:
oxygen, food, fruit, wood, water.
2. With your partner, list three items that plants must get from animals—either
directly or indirectly.
Student lists will vary, but should include some of the following items:
water, carbon dioxide, nutrients (from decaying animals), soil.
3. Using your answers to questions 1 and 2, construct a diagram that
illustrates the interdependence of plants and animals.
Student diagrams should indicate plant–animal interdependence.
Interest Grabber Answers
1. Mosses have leaves that are only one cell thick. What will likely happen to
these plants when the air is dry?
Water in their cells will evaporate, and they will dry out.
2. What special features might mosses have to protect them from dry air?
Possible answers: coatings on their leaves to prevent evaporation; ways to
store water for their cells.
3. Do you think mosses are better suited to live on riverbanks or on desert
slopes? Explain your answer.
Riverbanks; because the leaves of mosses are only one cell thick, they
probably dry out easily and so need moist environments, such as
riverbanks.
Interest Grabber Answers
List the functions of each of the following parts of a plant:
1. roots
Support the plant; take in water from the soil; anchor plant in soil
2. leaves
Capture sunlight; perform photosynthesis
3. stems
Support the leaves; carry water and food up and down the plant
4. flowers and cones
Reproduction
Interest Grabber Answers
1. In addition to sesame seeds, what are some other seeds that are found in or
on top of loaves of bread?
Most students will list poppy seeds and caraway seeds. In addition, some
“multi-grain” breads contain millet and flax seeds.
2. In addition to corn, what are some other seeds that are eaten as “vegetables”?
Peas and all types of beans, such as lima beans, black beans, kidney beans,
and so on
3. What are some seeds that you have eaten as snack foods?
Sunflower seeds, pumpkin seeds, peanuts
4. What types of nutrients are found in seeds?
Carbohydrates, proteins, and fats
5. Do seeds have the same nutritional value for plants as they do for animals?
Explain your answer.
Yes. Plants and animals use the same nutrients to live.
Interest Grabber Answers
1. Memorial Day, President’s Day, and Independence Day are all
examples of annual holidays. Using this information, how often does an
annual event occur?
Once every year
2. Bimonthly magazines are published every two months. Biweekly
newspapers are published every two weeks. Using this information,how
often does a biennial event occur?
Once every two years
3. Distinguish between the life spans of annual plants and biennial plants.
Their life spans differ in the number of years the plants live. Because
annual holidays occur once a year, annual plants would likely die after one
year. Because biennial events occur once every two years, biennial plants
would probably die after two years.