Transcript Lesson 3

Chapter Introduction
Lesson 1 What is a plant?
Lesson 2 Seedless Plants
Lesson 3 Seed Plants
Chapter Wrap-Up
Characteristics of Plants (cont.)
• Plants are multicellular.
• Some plants are
microscopic, while others
are some of the largest
organisms on Earth.
(c) Stephen Durr
CORBIS
Plant Adaptations (cont.)
A rigid cell wall
made of cellulose
surrounds the cell
membrane in a
plant cell.
Plant Adaptations (cont.)
• Other plants such as grasses and trees
have specialized tissues called vascular
tissue.
• Vascular
tissue is
composed of
tubelike cells
that transport
water and
nutrients in
some plants.
Brand X Pictures/PunchStock
Plant Classification
• Members of the plant
kingdom are organized
into groups called
divisions.
imagebroker/Alamy
• Like all organisms,
each plant has a
two-word scientific
name.
Sugar Maple
Magnoliophyta (Flowering Plants)
Acer saccharum
Do you agree or disagree?
1. All plants produce flowers and seeds.
2. Humans depend on plants for their
survival.
Seedless Plants
• How are nonvascular and vascular
seedless plants alike, and how are
they different?
Seedless Plants
• rhizoid
• frond
Nonvascular Seedless Plants
• Many scientists refer to all nonvascular
seedless plants as bryophytes.
• Because they lack vascular tissue,
the bryophytes usually live in moist
environments.
• Bryophytes do not have roots, stems,
or leaves.
Rhizoids are structures that anchor a
nonvascular seedless plant to a surface.
Nonvascular Seedless Plants (cont.)
• Mosses, liverworts, and hornworts are
bryophytes.
• Mosses, the most common bryophytes,
are small, green plants that usually grow
in shady, damp environments, but they
are able to survive periods of dryness.
• Mosses have multicellular rhizoids and
leaflike structures that grow on a
stemlike structure called a stalk.
Vascular Seedless Plants
Over 90 percent of plant species are
vascular plants which contain vascular
tissue in their stems, roots, and leaves.
Vascular Seedless Plants (cont.)
• The fronds, or leaves of ferns, make up
most of a fern.
• Ferns grow
in a variety
of habitats,
including
damp, swampy
areas and dry,
rocky cliffs.
Steven P. Lynch
Vascular Seedless Plants (cont.)
Unlike mosses, club mosses have roots,
stems, and leaves.
Steven P. Lynch
Vascular Seedless Plants (cont.)
• Horsetails have
small leaves
growing in circles
around the stems.
• Horsetail stems
are hollow, and the
tissues contain
silica, a mineral in
sand, that makes
them abrasive.
S. Solum/PhotoLink/Getty Images
Vascular Seedless Plants (cont.)
How are nonvascular and
vascular seedless plants alike?
How are they different?
• Many scientists refer to all nonvascular
seedless plants as bryophytes.
• Because vascular plants contain
tubelike structures that transport water
and nutrients, these plants usually are
larger than nonvascular plants.
• Humans use both vascular and
nonvascular plants for many purposes.
Which term refers to structures
that anchor a nonvascular
seedless plant to a surface?
A. bryophytes
B. fronds
C. rhizoids
D. roots
Which term refers to over 90
percent of plant species?
A. bryophotes
B. mosses
C. nonvascular
D. vascular
Which term is one scientists
use to refer to all nonvascular
seedless plants?
A. bryophytes
B. ferns
C. mosses
D. rhizoids
Do you agree or disagree?
3. Some plants move water only by
diffusion.
4. Mosses can grow only in moist, shady
places.
Seed Plants
• What characteristics are common to
seed plants?
• How do other organisms depend on
seed plants?
Seed Plants
• How are gymnosperms and
angiosperms alike, and how are they
different?
• What adaptations of flowering plants
enable them to survive in diverse
environments?
Seed Plants
• cambium
• xylem
• phloem
• stoma
Characteristics of Seed Plants
There are two groups
of seed plants—conebearing gymnosperms
and flowering
angiosperms.
Quarto, Inc./Photodisc/Getty Images
Steven P. Lynch
Characteristics of Seed Plants (cont.)
• All seed plants have vascular tissue that
transports water and nutrients
throughout the plant.
• They also have roots, stems, and leaves.
Characteristics of Seed Plants (cont.)
What characteristics do all seed
plants have in common?
Characteristics of Seed Plants (cont.)
The two types of vascular tissue are xylem
and phloem.
tissue
Science Use a group of cells
in an organism
Common Use a piece of
absorbent paper
Characteristics of Seed Plants (cont.)
• The cambium is a layer of tissue that
produces new vascular tissue and grows
between xylem and phloem.
• One type of vascular tissue—xylem—
carries water and dissolved nutrients
from the roots to the stem and the
leaves.
Characteristics of Seed Plants (cont.)
xylem
from Greek xylon, means “wood”
Characteristics of Seed Plants (cont.)
• Two kinds of xylem
cells are tracheids and
vessel elements.
• All vascular plants have
xylem that is composed
of tracheids.
• Tracheid cells die at
maturity, leaving a
hollow tube that water
can flow through freely.
Characteristics of Seed Plants (cont.)
• Xylem in flowering
plants also includes
cells called vessel
elements.
• The end of vessel
elements have larger
openings than those
found in tracheid cells.
Water can pass through
easily.
Characteristics of Seed Plants (cont.)
• Another type of
vascular tissue—
phloem—carries
dissolved sugars
throughout a plant.
• Phloem is composed
of two types of cells—
sieve-tube elements
and companion cells.
Characteristics of Seed Plants (cont.)
• Sieve-tube elements
are long, thin cells
stacked end-to-end to
form long tubes.
• A companion cell
helps control the
functions of the
sieve-tube element.
Characteristics of Seed Plants (cont.)
• Roots anchor a plant, either in soil or
onto another plant or an object such as
a rock.
• All root systems help a plant absorb
water and other substance from the soil.
Characteristics of Seed Plants (cont.)
• The part of a plant that connects its roots
to its leaves is the stem.
• Stems support branches and leaves,
and their vascular tissues transport
water, minerals, and food.
• Plant stems are usually classified as
either herbaceous, which are usually soft
and green, or woody, which are stiff and
typically not green.
Characteristics of Seed Plants (cont.)
• Most leaves are the major site of
photosynthesis for the plant.
• The top and bottom layers of a leaf are
made of epidermal tissue.
Dr. Gerald Van Dyke/Visuals Unlimited/Getty Images
Most leaves have a small
opening in the epidermis
called stomata.
Characteristics of Seed Plants (cont.)
When the stomata open, carbon dioxide,
oxygen, and water vapor can pass through
them.
Dr. Gerald Van Dyke/Visuals Unlimited/Getty Images
Characteristics of Seed Plants (cont.)
Below the upper epidermis are rows of
tightly packed cells called palisade
mesophyll cells where photosynthesis
mainly occurs.
Gymnosperms
• In gymnosperms,
seeds are produced
in a cone.
• Different types
of gymnosperms
include conifers,
cyads, ginkoes,
and gnetophytes.
Siede Preis/Getty Images
Angiosperms
• There are more than 260,000 species
of flowering plants, or angiosperms.
• Almost all of the food eaten by humans
comes from angiosperms or from
animals that eat angiosperms.
Angiosperms (cont.)
How do other organisms depend
on seed plants?
Angiosperms (cont.)
• Angiosperms
produce seeds that
are part of a fruit.
• Fruit grows from
parts of a flower.
• All angiosperms
produce flowers.
CORBIS
Angiosperms (cont.)
How are angiosperms and
gymnosperms alike, and how
are they different?
Angiosperms (cont.)
Plants that grow, flower, and produce
seeds in one growing season are called
annuals.
Angiosperms (cont.)
• Biennials complete their life cycles in
two growing seasons.
• During the first year, the plant grows
roots, stems and leaves.
• In the second growing season the plant
produces new stems, leaves, flowers,
and seeds.
Angiosperms (cont.)
• Perennial plants, like trees and shrubs,
can live for more than two growing
seasons.
• Flowering plants are organized into two
groups—monocots and dicots.
• These groups are based on the number
of leaves in early development, or
cotyledons, in a seed.
Angiosperms (cont.)
What adaptations of flowering
plants enable them to survive in
diverse environments?
• Angiosperms are flowering plants.
• Seed plant have many adaptations
that enable them to survive in
diverse environments.
• Seed plants have many uses.
Which refers to the vascular tissue
that carries water and nutrients
from the roots up the plant?
A. cambium
B. phloem
C. stomata
D. xylem
What plant part is usually
classified as either herbaceous
or woody?
A. leaves
B. roots
C. stems
D. xylem
Which plant part is the major site
of photosynthesis?
A. roots
B. leaves
C. stems
D. stomata
Do you agree or disagree?
5. Some mosses and gymnosperms are
used for commercial purposes.
6. All plants grow, flower, and produce
seeds in one growing season.
Key Concept Summary
Interactive Concept Map
Chapter Review
Standardized Test Practice
Different plant species
have different
adaptations that
enable them to survive
in most of the
environments
on Earth.
Lesson 1: What is a plant?
• Plants are multicellular producers
composed of eukaryotic cells with cell
walls composed of cellulose. Many
plant cells have chloroplasts.
• Plants have developed adaptations, such as a cell
wall for support, a cuticle to prevent water loss and
to provide protection from insects, vascular tissue to
transport materials, and numerous reproductive
strategies, to survive in Earth’s changing
environments.
• Member of the plant kingdom are classified into
groups called divisions, which are equivalent to
phyla in other kingdoms. Plants have two-word
scientific names.
Lesson 2: Seedless Plants
• Vascular and nonvascular
seedless plants are multicellular
producers composed of
eukaryotic cells. Nonvascular
seedless plants usually are
smaller than vascular seedless
plants, lack vascular tissue,
have rhizoids instead of roots to
anchor them, and lack true
stems or leaves.
Lesson 3: Seed Plants
• All seed plants make seeds and reproduce.
Seed plants have leaves, stems, roots, and
vascular tissue—xylem and phloem.
• Seed plants are important to other organisms for
various reasons, including for food, for the addition of
oxygen to the environment, and for commercial uses.
• Gymnosperms and angiosperms are both seed plants.
Angiosperms produce flowers; gymnosperms do not.
The seeds of angiosperms are surrounded by fruit. The
seeds of gymnosperms are not surrounded by fruit.
• Flowering plants have adaptations that enable them to
survive in diverse environments. Such adaptations
include leaves, stems, vascular tissue, roots, flowers,
and seeds protected by a fruit.
Which is an organic compound
made of chains of glucose
molecules?
A. cellulose
B. cuticle
C. vascular tissue
D. xylem
Which is made of tubelike cells
that transport water and nutrients
in some plants?
A. cell wall
B. cellulose
C. cuticle
D. vascular tissue
Which term is another name for
the leaves of ferns?
A. bryophytes
B. fronds
C. rhizoids
D. stomata
Which term refers to the vascular
tissue that carries dissolved
sugars throughout a plant?
A. phloem
B. roots
C. rhizoid
D. stomata
Which part of a leaf controls the
movement of gases in and out of
the leaf?
A. stomata
B. palisade mesophyll
C. epidermal tissue
D. cambium
The first land plants probably
lived in what kind of area?
A. cold
B. dark
C. dry
D. moist
Which refers to the chemical in
many plants that strengthens the
plant’s cellulose?
A. cuticle
B. lignin
C. phloem
D. vascular tissue
Which do club mosses NOT have?
A. stems
B. roots
C. leaves
D. flowers
Which are nonvascular seedless
plants, or bryophytes?
A. club mosses
B. ferns
C. horsetails
D. mosses
Which produces new vascular
tissue and grows between xylem
and phloem?
A. sieve-tube elements
B. cambium
C. seeds
D. stomata