Transcript Bio. Ch. 22 - NorthMacAgScience

Section 22-1
 Science
Starter
 Life
as we know it today could not exist
without plants.
Plants provide us with many essential
items other than food.
 1.
With your partner, list five items you
use
daily that are byproducts of plants.
Go to
Section:
Section 22-1

22–1 Introduction
to Plants
A. What Is a Plant?
B. The Plant Life Cycle
C. What Plants Need to Survive
1. Sunlight
2. Water and Minerals
3. Gas Exchange
4. Movement of Water and Nutrients
D. Early Plants
1. Origins in the Water
2. The First Plants
E. Overview of the Plant Kingdom
Go to
Section:
 What
do we already know about plants?
• How many cells?
• Eukaryote or prokaryote?
• How do they get food?
• Special structures in cells?
 Plants
are multicellular eukaryotes that
have cell walls, made of cellulose.
 They develop from multicellular embryos
 Carry out photosynthesis using green
pigment called chlorophyll.
 They are autotrophs
 Examples:
 “Stationary
animals that eat sunlight!”
 Differences between plants and animals:
 Two
generations:
• The haploid (N) gametophyte, or gamete-
producing plant
• The diploid (2N) sporophyte, or sporeproducing plant
 Spores are reproductive cells that produce a new
individual by mitosis.
 This may differ dramatically from phylum to phylum!
Section 22-1
Haploid
Diploid
MEIOSIS
Spores
(N)
Gametophyte Plant (N)
Sporophyte Plant (2N)
Sperm
(N)
Eggs
(N)
FERTILIZATION
Go to
Section:
 Sunlight
• To carry out photosynthesis
• Typically photosynthetic organs such as leaves
are broad and flat to maximize light absorption.
 Water
and Minerals
• Water also needed for photosynthesis
• Minerals can only be taken in through water
• Adaptations to limit water loss
 Gas Exchange
• Oxygen needed to support respiration
• Carbon dioxide needed for photosynthesis
• The problem: Exchange these gasses without losing
a lot of water
 Movement of Water and Nutrients
• Absorption happens at roots, but must move
throughout entire plant
• Specialized tissues
• OR
• Diffusion
 Read
p. 553 first two paragraphs!
 Origins in the Water:
• The first plants evolved from an organism much
like the multicellular green algae living today

The First Plants:
• Read paragraph 2 on page 554
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
Go to
Section:
 Divided
into FOUR groups, based on
three important features: fig. 22-7
• 1. water-conduction tissues
• 2. seeds
• 3. flowers

Section 22-1
Cone-bearing plants
760 species
Ferns and
their relatives
11,000 species
Mosses and
their relatives
15,600 species
Go to
Section:
Flowering
plants
235,000 species
Section 22-2

22–2
Bryophytes
A. Groups of Bryophytes
1. Mosses
2. Liverworts
3. Hornworts
B. Life Cycle of Bryophytes
1. Dependence on Water
2. Life Cycle of a Moss
C. Human Use of Mosses
Go to
Section:
 Byrophytes
• AKA nonvascular plants
• Do not have vascular tissues (tissue that are
responsible for conducting water and nutrients)
Have a life cycle that depend on water
for reproduction.
 Draw up water by osmosis

• Can only be a few centimeters off the ground
• Example: Mosses
 Characteristics:
• Must be low growing
• Usually found in shaded or moist areas

Include:
• Mosses
• Liverwarts
• Hornwarts
 Most
common bryophyte
 Belong to phylum Bryophyta
 Grow near water
 Do not have true roots, instead they have:
• Rhizoids: long thin cells that anchor plant into
the ground, helps to absorb water and minerals
from surrounding soil
Section 22-2
Capsule
Sporophyte
Stalk
Stemlike
structure
Leaflike
structure
Rhizoid
Go to
Section:
Gametophyte
 Looks
like a flat leaf, attached to the
ground (shaped like a liver)
 Phylum: hepaticophyta
 Reproduce asexually by gemmae
• Small multicellular spheres that contain haploid
cells.
• These cells are washed off the parent plant, and
they then begin a new plant
 The
gametophyte is the dominane,
recognazible stage of the life cycle, and
it’s the stage that carries out most of the
plant’s photosynthesis
 For
fertilization to occur, there must be
WATER!
 Read
page #558
 Protonema: after a BRYO reporduces, it
germinates and begins a tangles mass of
green filimants
 Antheridia: part of BRYO where sperm
are produced
 Archegonia: part of BRYO where the egg
is produced
Haploid (N)
Diploid (2N)
MEIOSIS
Spores
(N)
Protonema
(young gametophyte)
(N)
Male
gametophyte
Female
gametophyte
Mature
sporophyte
(2N)
Capsule
(sporangium)
Gametophyte
(N)
Antheridia
Young
sporophyte
(2N)
Sperm
(N)
Archegonia
Zygote
(2N)
Gametophyte
(N)
Egg
(N)
FERTILIZATION
Go to
Section:
Sperm
(N)
Section 22-3

22–3 Seedless
Vascular Plants
A. Evolution of Vascular Tissue
B. Ferns and Their Relatives
1. Club Mosses
2. Horsetails
3. Ferns
C. Life Cycle of Ferns
Go to
Section:
 Vascular
tissues: specialized tissue used
to conduct water and nutrients through
the body of the plant.
• These types of plants can grow taller

Were byrophytes vascular or
nonvascular plants?
 Two
types of Vascular Tissue:
• Xylem: conducts water upwards from roots to
every part of thee plant
• Phloem: transports nutrient solutions
Both of these can work against the force
of gravity.
 Vascular plants produce lignin the
substance that make cell wall rigid.

• Lignin allows vascular plants to grow upright
and reach great heights.
 Seedless
vascular plants include mosses,
horsetails and ferns.
 These all have true:
• Roots: underground organs that absorb water
and minerals.
• Leaves: contain bundles of vascular tissues,
photosynthesis is carried out here.
• Veins: composed of xylem and phloem
• Stems: supporting structures that connect roots
and leaves. Carry water and nutrients between
them.
 More
than 11,000 species of ferns
 Evolved over 350 million years ago.
 Page #562 diagram of a fern
• The large leaves = Fronds
• Rhizomes: creeping under ground stems
 Ferns
and other vascular plants have a
life cycle in which the diploid sporophyte
is the dominant life stage.
 Sori: spores release from sporangia. Must
be carried by wind or water.
• Looks like rust spot underside of the frond
Section 22-3
MEIOSIS
Sporangium
(2N)
Haploid gametophyte (N)
Diploid sporophyte (2N)
Frond
Spores
(N)
Mature
sporophyte
(2N)
Developing
sporophyte
(2N)
Antheridium
Young
gametophyte
(N)
Mature
gametophyte
(N)
Sperm
Gametophyte
(N)
Egg
Sporophyte
embryo
(2N)
Go to
Section:
Archegonium
FERTILIZATION
Section 22-4

22–4 Seed
Plants
A. Reproduction Free From Water
1. Cones and Flowers
2. Pollen
3. Seeds
B. Evolution of Seed Plants
C. Gymnosperms—Cone Bearers
1. Gnetophytes
2. Cycads
3. Ginkgoes
4. Conifers
5. Ecology of Conifers
Go to
Section:
 Seed
Plants are divided into two groups:
• Gymnosperms: bear their seed directly on the
surfaces of cones
 Examples: Conifers (pine and spruce trees)
• Angiosperms: (AKA flowering plants) bear their
seeds within a layer of tissue that protects the
seed.
 Examples: grasses, flowering trees, shrubs, wildflower

 Still
have alternating life cycle b/t
gamete and sporophyte stages.
 Seed plants DON’T need water to
reproduce!
• This means seed plants can live about anywhere

Adaptations that allow seed plants to
reproduce without water include: flowers
or cones, the transfer of sperm by
pollination and the protection of embryos
in seeds.
 Seed
plants do not require water for
fertilization.
 Adaptations that allow this include:
• Flowers or cones
• Transfer of sperm by pollination
• Protection of embryos in seeds
 Cones: seed-bearing
structures of
gymnosperms
 Flowers: seed-bearing structure of
angiosperms.
 The
entire male gametophyte is
contained in a tiny structure called
pollen grain.
• This PG is carried to the female gametophyte by
wind, insects, birds, etc.

This transfer of pollen from the male to
the felmale gametophyte is pollination
 Seed: embryo
of a plant, encased in a
protective covering and surrounded by a
food supply.
 After
fertilization the zygote contained
with in the seed grows into a tiny plante
called the embryo.
Section 22-4
Seed coat
Seed
Embryo
Wing
B
Stored
food supply
 The
Go to
Section:
embryo the early
A
developmental
stage
of the sporophyte
The seed coast
surrounds and
protects the embryo
and keeps it from
drying out!
 Read
Evolution of Seed plants p. 566
 Gymnosperms
• Reproduce with seeds that are exposed
• Means “naked seed”
• Conifers are most common in our area
 Pine, spruce, cedars, redwoods, etc.
• Ginkgoes – read p. 567
Section 22-4
Comparing Features of Seed Plants
Feature
Seeds
Reproduction
Examples
Go to
Section:
Gymnosperms
Angiosperms
Section 22-4
Comparing Features of Seed Plants
Go to
Section:
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
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
Go to
Section:
 Flowering
plants originated on land and
quickly came to dominate life
 Angiosperms have reproductive organs
known as flowers.
• Evolutionary advantage – transport of pollen
• More efficient than wind pollination of GSperm

Asperms contain ovaries, witch
surronund and protect the seed
• Asperm actually means “enclosed seed”
 Figure
22-24 page 569
 Fruit: a thick wall of tissue surrounding
the enclosed seed.
• Animals spread the seed by eating fruit and
“depositing” seed at another location
• Another evolutionary advantage!
 Classification
by 3 groups
 These groups can overlap
1. Monocots and dicots
2. Woody and herbaceous
3. Life cycle
 Monocotyledonae
 Dicotyledonae
 Figure
22-25 page 570
Section 22-5
Monocots
Go to
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
 Based
on stem characteristics
 Woody plants: thick cell walls that
support plant.
• Trees & shrubs

Herbaceous plants: must be smooth
and nonwoody.
• Dandelions, petunias, sunflowers, geraniums
3
groups based on length of time
 Read page 572
 Annuals: plants that complete life cycle
in one year
• EX: marigolds, petunias, zinnias
 Biennial: Year
one grow and generate
roots. Year two produce flowers and
seeds, then die
• Parsley, celery and foxglove
 Perennial: Live
for many years.
Section 22-5
Plants
are categorized as
Annuals
that complete
their life cycle in
Perennials
that complete
their life cycle in
2 years
Go to
Section:
that complete
their life cycle in
Section 22-5
Plants
are categorized as
Go to
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