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Sylvia S. Mader
Immagini e
concetti
della biologia
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
A10 - Protists,
plants and fungi
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista
Protists contain membrane-bounded organelles
as mitochondria and chloroplasts.
Endosymbiosis theory:
as mitochondria and chloroplasts have their own DNA, they
may have derived from the symbiosis of an aerobic bacteria
(or cyanobacteria) engulfed by a primitive prokaryotic cell.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista
Protists include very diverse organisms
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista
Protists are diverse in cellular organization,
nutrition strategy, reproduction and locomotion.
Considering the nutrition strategies,
Protists are divided into four groups.
•Protozoan and slime molds: heterotrophic by
ingestion (endocytosis) or parasitic.
•Water molds: heterotrophic by absorption or parasitic.
•Algae: photosynthetic.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Protozoan
Protozoan are protists with animal-like behavior
heterotrophic strategy and movement:
•Zooflagellates
•Euglenoids
•Amoeboids
•Foraminiferans and Radiolarians
•Ciliates
•Sporozoan
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Protozoan
Zooflagellates
Move by flagella and are parasitic (some of them can
cause diseases to humans).
Euglenoids
Move by flagella, are flexible and often contain
chloroplasts. Live in fresh waters.
Amoeboids
Move and ingest by pseudopods, bulges of the
cytoplasm. In salt water compose the zooplankton.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Protozoan
Foraminiferans and Radiolarians
Produce a test (or shell) in calcium carbonate and silicon
respectively. Dead Foraminiferans and Radiolarians
compose the rocks of the ocean floors.
Ciliates
Move by cilia and reproduce both asexually (binary
fission) and sexually (conjugation).
Sporozoans
Are not motile. They are parasitic and form spores as
i.e. the Plasmodium, causing Malaria.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Slime molds
Plasmodial slime molds
Phagocytize decomposing plant
material in forests and agricultural
fields.
Cellular slime molds
Microscopic protists that exist as individual amoeboid cells.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Water molds
Water molds
More than 500 species inhabiting mainly aquatic
environments and feeding on dead fish and insects
(saprophyte).
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Algae
Diatoms
Are a major group of unicellular algae
inhabiting fresh and salt water and are one of
the most common types of phytoplankton.
Have a unique cell wall made of silicon called
a frustule.
Cyclotella
Dinoflagellates
Marine producers, as diatoms, and have a cell wall made
of cellulose plates and silica with two flagella.
Cellulose plates
Flagella
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Algae
Red and brown algae
Are multicellular complex protists and are the largest
groups of eukaryotic algae.
Are commonly used in pharmacy and as an important
source of food.
Chondrus crispus, red algae
Fucus, brown algae
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Algae
Green algae
have diverse forms, from flagellated unicellular to
filamentous colonial and multicellular.
Green algae photosynthesize as plants but they cannot
reproduce on land.
Volvox, colonial
Ulva, multicellular
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Protista: Algae
Green algae life cycle has many variations: haploid,
with alternation of generations or diploid.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Plantae
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Plantae
Fossil records show that plants evolved from fresh
water green algae.
Evidences:
•Both plants and green algae have type a and type b
chlorophylls
•Both plants and green algae store carbohydrates as
starch
•Both plants and green algae have cellulose in the cell
wall
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Plantae
Derived characters
1.The embryo is protected within the plant body
2.Developed vascular tissue
3.Seed
4.Evolution of the flower
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Plants evolution
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Plants have alternation of
generations
Sporophyte
Diploid (2n) generation, it
produces haploid spores
by meiosis.
Gametophyte
Haploid (n) generation, it
produces gametes (eggs
and sperms) by mitosis.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Plants have alternation of generations
During evolution, the sporophyte became dominant over
the gametophyte as plants adapted to life on land.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Bryophytes: non vascular plants
Low-lying non vascular plants
Antheridium is the organ producing male gametes.
Archegonium is the organ producing female gametes.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Bryophytes: nonvascular plants
•The dependent sporophyte produces windblown spores
•The dominant gametophyte produces water-swimming
flagellated sperms
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Pteridophytes: ferns and their allies
Moderate size, seedless vascular plants that prefer moist
locations.
Leaves are called fronds and can be divided into small
leaflets.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Pteridophytes: ferns and their allies
•The dominant sporophyte produces windblown spores
•The independent and separate gametophyte produces
water-swimming flagellated sperms
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Gymnosperms: naked seeds
Large cone bearing seeds plants that form big tree
forests.
This group includes Cycads, Ginkgoes, Gnetophytes and
Conifers (evergreen trees).
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Gymnosperms: naked seeds
•Dominant sporophyte produces pollen cones and seed
cones
•Pollen cones produce windblown pollen (male
gametophyte)
•Seed cones bear ovules which develop into naked seeds
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Carboniferous forests
300 MA ago a great swamp forest encompassed the
actual Europe, Ukraine, and USA.
The partially decomposed remains of those trees were
covered by swamp sediments that became sedimentary
rocks.
This organic matter formed big deposits of the coal we use
today as fossil fuel.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperms: flowering plants
Angiosperms where the last plants to evolve during
Cenozoic era (about 65 MA ago) in coevolution with flying
insects (pollinators).
Plants of all sizes, living in all habitats.
•Dominant sporophyte bears flowers which produce
pollen grains (male gametophyte) and enclose ovules
(female gametophyte) within an ovary.
•Ovules become seeds that protect a sporophyte embryo.
•Fruits develop from ovary.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperms: flowering plants
Flowering plants are divided into two
main structural systems:
1.Shoot system (include stems,
leaves and flowers);
2.Root system (primary root and root
hairs).
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperms: flowering plants
Stem is divided into nodes and
internodes.
It supports leaves and transports
fluids between the roots and the
shoots (vascular system).
Leaves carry on photosynthesis.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperms: flowering plants
Roots anchor the plant,
absorb water and nutrients
from the ground and can
store water and other plant
products.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperm derived characters
The flowers, are the reproductive organs of
angiosperms and distinguish them from other plants.
Protect the ovary
Attract specific
pollinators
Protect the
flower before
blooming
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperm derived characters
The stamen, is the pollen-producing reproductive organ
of a flower.
Stamens have contributed to the diversification of
angiosperms with adaptations to specialized pollinators.
Anther
Filament
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperm derived characters
Monocotyledons and Cotyledons
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Angiosperms life cycle
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Plants absorb CO2 and free O2
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Plants require minerals
Minerals are inorganic substances (ions or compounds)
that can be transformed by plants into organic molecules.
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Kingdom Fungi
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Fungi: heterotrophic and saprophytic
Fungi are important in nutrient cycling as they
decompose, especially as saprotrophs and symbionts,
degrading organic matter to inorganic molecules for plants.
The fungal body is made up by filaments and hyphae
interconnected in a network called mycelium
Fungal cells contain chitin and glycogen.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Fungi life cycle
Fungi produce windblown
spores during both sexual
and asexual reproduction.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Fungi
Fungi are divided into three main groups, depending on
the reproductive organs:
1.Zygomycota (black bread mold) have zygospores;
2.Ascomycota (sac fungi and yeasts) have an ascus;
3.Basidiomycota (mushrooms) have a basidium.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012
Kingdom Fungi
Fungi have mutualistic relations with algae and plants.
Lichen is a symbiotic association
between a fungus and a
cyanobacteria or a green algae .
Mycorrhizal fungi form
association with plants roots,
increasing the nutrient
absorption surface.
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Sylvia S. Mader Concepts of Biology © Zanichelli editore, 2012