Transcript a20 Plants and Fungi

Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms
o Importance of Plant Diversity
Fungi
o Characteristics
o Types
Colonizing Land
• Plants
– Are terrestrial organisms.
– Are multicellular eukaryotes that make organic
molecules by photosynthesis (photoautotrophs).
• Living on land poses different problems than living
in water does.
– Plants require structural specializations, such as
roots and shoots.
Anatomy of a Plant and Terrestrial Adaptations
Figure 16.2
• Leaves
– Are the main
photosynthetic
organs of most
plants.
– Have stomata for
gas exchange.
– Contain vascular
tissue for
transporting vital
materials.
Reproductive Adaptations
• Plants produce their
gametes in protective
structures called
gametangia.
• In plants, but not
algae, the zygote
develops into an
embryo while still
contained within the
female parent.
Alternation of Generations Seen in Plant Life Cycles
Both the diploid and the haploid life stages are multicellular
Where Did Land Plants Come From?
• Molecular comparisons and other evidence place a group of
green algae called charophyceans closest to plants. Plants
evolved from a water-based algae.
Evolutionary Novelties and Clades Arising in Plant Evolution
Figure 16.7
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms
o Importance of Plant Diversity
Fungi
o Characteristics
 Ecological Impact
Bryophytes (Mosses, Liverworts, and Hornworts)
• Mosses
– Have no true roots (filamentous rhizoids instead:
terrestrial adaptation)
– Lack vascular tissue
– Must live in or near standing water
– Have a waxy cuticle to prevent dehydration
(major terrestrial adaptations)
– Developing embryonic plants are retained within
the gametangium (ovary) of the mother plant
– Have a dominant gametophyte (1n) generation
Bryophytes Are the Simplest Plants
Figure 16.8
Mosses Have a Dominant Gametophyte (1n) Generation or Life Stage
Moss Life Cycle
Figure 16.10
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms
o Importance of Plant Diversity
Fungi
o Characteristics
 Ecological Impact
Evolutionary Novelties and Clades Arising in Plant Evolution
Figure 16.7
Ferns
• Ferns
– Have true roots
– Have vascular tissue (xylem and phloem)
– Must have water nearby during reproduction
– Forms haploid spores that germinate into tiny
haploid gametophyte
– Dominant sporophyte (2n) generation
– Formed huge swamp forests about 360-250
million years ago (Carboniferous Period)  fossil
fuels
Adult Ferns, Shoots, and Reproductive Structures
Figure 16.11
Ferns Have a Dominant Sporophyte (2n) Generation
2n
1n
Swampy Fern-Tree Forests Common 300 Million Years Ago
Fern Life Cycle
Figure 16.12
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms (Conifers)
 Angiosperms
o Importance of Plant Diversity
Fungi
o Characteristics
 Ecological Impact
Evolutionary Novelties and Clades Arising in Plant Evolution
Figure 16.7
Gymnosperms (Mostly All Cone-Bearing Plants)
•
A drier, colder climate at the end of the Carboniferous period favored
the evolution of gymnosperms, the first seed plants.
•
The descendants of early gymnosperms
–
•
Include the conifers, cone-bearing plants.
Gymnosperms have:
–
Needle-like or scale-like leaves
–
Male and female cones to make pollen and eggs
–
“Naked” ovaries within cones (not fully enclosed by tissue)
–
Eggs develop into seeds
–
Wind pollinated, form winged seeds
–
Dominant diploid (sporophyte) generation
–
Persistent leaves (evergreen)
Gymnosperm (Conifer) Needles and Leaves
Arrangements of
needles on a stem
Most Gymnosperms Are Evergreen and Reproduce with Cones
Figure 16.13
The Ovaries in a Female Cone are “Naked” or Incompletely
Housed By Integument Tissue
Pine Life Cycle
Figure 16.16
Gymnosperms Have a Dominant Sporophyte Generation (e.g. Adult Trees)
Mosses
Ferns
Gymnosperms
Figure 16.14
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms (Flowering Plants)
o Importance of Plant Diversity
Fungi
o Characteristics
 Ecological Impact
Angiosperms
•
Angiosperms
–
Supply nearly all of our food and much of our fiber for textiles.
•
More efficient water transport and the evolution of the flower help
account for the success of the angiosperms.
•
Angiosperms (Flowering Plants) have:
–
Flowers (both sex parts) instead of cones
–
Seeds inside enclosed ovaries
–
Seeds that are further embedded in nutritious tissue within fruits
–
Broad and flattened leaves which are deciduous
–
A dominant sporophyte (diploid) generation
–
Are usually animal pollinated (some wind)
Anatomy of a Flower
Bee Pollinating
Figure 16.17
Angiosperm (Flowering Plant) Leaves Are Broad and Flattened
The Life Cycle of an Angiosperm (Sporophyte Dominant)
1n
Plant Fertilization
Seed Development
Flowering Plant
Life Cycle (time lapse)
Fruit Development
2n
Figure 16.18
Angiosperm Fruits Are Fleshy
• The seed being
enclosed within an
ovary distinguishes
gymnosperms from
angiosperms.
• A fruit is a
ripened ovary that
helps protect the
seed and increase
its dispersal
Flowering/Fert
Seeds
Fruit
Seed Dispersal Strategies of Plants
Figure 16.19
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms
o Importance of Plant Diversity
 Fungi
o Characteristics
o Types
Fungi
• Characteristics of Fungi:
– Eukaryotic, and most are multicellular.
– Cell walls of the polysaccharide chitin
– Chemoheterotrophic nutrition, 30% are parasitic
– Constructed of thin filaments called hyphae that form
mycelia
– Fungi reproduce by releasing spores that are produced
either sexually or asexually.
– Include the molds, yeasts, and club fungi (mushrooms)
– Fungi are extremely important to ecosystems because they
decompose and recycle organic materials.
Diverse Forms Within Kingdom Fungi
Figure 16.20
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms
o Importance of Plant Diversity
Fungi
o Characteristics
o Types
Club Fungi: The Mushrooms
Figure 16.21
Molds: Mats of Mycelia
Some molds, like Penicillium
produce antibacterial chemicals
(antibiotics)
Fungal Reproduction and Nutrition
Yeast: Single-celled fungi
Saccharomyces cerevesiae: baker’s and brewer’s yeast
Candida albicans: pathogenic yeast causing vaginal yeast
infections and systemic candidiasis in AIDS patients
Parasitic Fungi
• Of the 100,000 known species of fungi, about 30%
make their living as parasites.
Most Plants Have Mycorrhizae Fungi On Their Roots
Figure 16.3
Lichens Are Classified As Fungi But Are Part Protistan
• Lichens
– Are symbiotic
associations between
fungi and algae.
– Are an example of a
cooperative living
arrangment called
mutualism.
Plants, Fungi, and the Move onto Land
CHAPTER 16
Plants
o Adaptation of Plants to Terrestrial Life
o Types of Plants
 Mosses (Bryophytes)
 Ferns
 Gymnosperms
 Angiosperms
o Importance of Plant Diversity
Fungi
o Characteristics
o Types