Transcript Chapter 21 * Plant evolution and adaptations

Section 1-
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Plants are vital to our
survival and provide
oxygen for us to breathe
and many of the foods
that we eat.
They make our lives
comfortable by providing
products for clothing,
furniture, and building
materials.
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Modern day plants and
algae share the following
characteristics:
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Cell walls made of cellulose
Formation of a cell plate during
cell division
Use of chlorophyll during
photosynthesis
Similar ribosomal RNA
Food stored as starch
Same types of enzymes in
vesicles.
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These shared
characteristics between
plants and algae suggest
a common ancestor.
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Cuticle – Fatty coating on the outside
of plant leaves that helps to protect
the leaf from invading organisms and
prevents unwanted water loss.
STOMATA – Openings in the outer
layer of leaves that allows for the
exchange of gases in plants with a
cuticle.
Vascular Tissues – Specialized
transport tissues that also provide
support and structure.
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Reproductive Strategies
 Some land plants reproduce
through spores that have a
waterproof protective covering
 Some land plants reproduce
through the production of seeds.
 Some plants produce both
(alternation of generations)
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There are 12 plant divisions (same
as phyla in other organisms).
These 12 divisions can be placed
into two groups:
 Vascular
◦ Seed Producers
◦ Non-seed producers
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Club mosses, ferns, and horsetails
Non-vasucular
◦ Mosses, hornworts, and liverworts
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Vascular plants contain
specialized transport
tissues that also provide
support and structure.
Non-vascular plants do not
contain these specialized
tissues, therefore, they
seldom grow very tall.
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