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Diversity of Eukaryotes. CHAPTERS 3 and 4. The Mind-Boggling Diversity of Life. The Eukarya domain contains four kingdoms Protista Plantae Fungi Animalia Eukaryotes evolved sometime after prokaryotes populated the Earth. The Dawn of Eukarya. Key evolutionary features of eukaryotes: - PowerPoint PPT Presentation
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Diversity of Eukaryotes
CHAPTERS 3 and 4
The Mind-Boggling Diversity of Life
• The Eukarya domain contains four kingdoms– Protista– Plantae– Fungi– Animalia
• Eukaryotes evolved sometime after prokaryotes populated the Earth
The Dawn of Eukarya
• Key evolutionary features of eukaryotes:
– Presence of a nucleus – Membrane-bound internal compartments– Larger cell size– Sexual reproduction– Multicellular (not all are though)
Eukaryotes Have Subcellular Compartmentalization and Larger Cells• Eukaryotic DNA
is in a nucleus• Increased
complexity allows eukaryotes to function with greater efficiency
• Eukaryotes are thousands of times larger in volume than prokaryotes
Sexual Reproduction Increases Genetic Diversity
• Sexual reproduction increases genetic diversity by producing offspring that are different from each other and from both parents.
Protista: The First Eukaryotes
Protista: The First Eukaryotes• The protists include any
organism that do not fit into the other kingdom classifications– simple organization – No specialized tissues– Single cellular– Mobile- flagella, cilia, or
pseudopodia
Protista: The First Eukaryotes
• Live in almost any environment that contains liquid water
• Many protists, such as the algae, are photosynthetic
Protists are Autotrophs, Heterotrophs, or Mixotrophs
• What is an autotroph? What is a producer?
• What is an heterotroph? What is a consumer?
• What is an mixotrophs?
Protists are Autotrophs, Heterotrophs, or Mixotrophs
• Algae are autotrophic producers that use energy from sunlight to carry out photosynthesis and release oxygen gas as a by-product
Protists are Autotrophs, Heterotrophs, or Mixotrophs
• Heterotrophic protists rely on other organisms for energy
Protists are Autotrophs, Heterotrophs, or Mixotrophs
• Mixotrophs obtain energy from a variety of sources, depending on environmental conditions– Photosynthesize in light– Hunt in dark
Euglena viridis
Some Protists Are Pathogens
• Some of the best-known protists are disease-causing pathogens– Malaria ---
Giardia
Fungi: A World of Decomposers
Fungi• Fungal cells have a
protective cell wall that can produce chitin to help protect the cell
• Fungi can be multicellular or single-celled species
• DNA comparisons show that fungi are more closely related to humans than to plants!
Fungi• Fungi can be
multicellular or single-celled species
• The body of a multicellular fungus is called the mycelium and is made up of many mycelial strands of hyphae
Fungi Play a Key Role as Decomposers
• Fungi are heterotrophs that decompose organic materials
• Fungi are the most important decomposers on land
Fungi Can be Dangerous Parasites• Parasitic fungi grow on the
tissue of living organisms
Athlete's Foot
Yeast
Ring “worm”
Lichens and Mycorrhizae: Collaborations between Kingdoms
• Symbiosis is the process of two organisms working together in close association
• Fungi have formed beneficial relationships with members of almost every kingdom
Lichens Contain a Fungus and a Photosynthetic Microbe
• A lichen is a positive association between:– a photosynthetic
microbe (algae or cyanobacteria) and a fungus
• Lichens are pioneers of barren environments, helping to facilitate soil formation
Mycorrhizae are Beneficial Associations between a Fungus and the Plant Root
• Mycorrhizae are beneficial associations between a fungus and the plant root
• Plant gets more water with Mycorrhizae
• Mycorrhizae gets sugars from plant
Plantae
Plantae• Plants are multicellular autotrophs that use
specialized organelles called chloroplasts to carry out photosynthesis
Plantae
• Bryophytes – earliest land
plants– mosses, liverwort,
and hornwort• Gymnosperms– conifers
• Angiosperms– flowering plants
Plants Had to Adapt to Life on Land
• In order to evolve on land, plants developed a waxy cuticle that prevents them from drying out
Plants Had to Adapt to Life on Land
• Stomata are pores that open and close to allow the carbon dioxide needed for photosynthesis to enter the leaves
Plants: Vascular System
• Vascular tissue:– Phloem• Transports food
molecules like sugar• Flows down
– Xylem • transports water and
dissolved nutrients• Flows up
Gymnosperms• Gymnosperms were the first plants to
evolve pollen and seeds– The evolution of seeds contributed
to their success• Pollen – contains sperm cells– dry and powdery– produced in great quantities
• Seed – plant embryo and a short
supply of food encased in a protective seed coat
Male Cone
Female Cone
Angiosperms
• Angiosperms produce flowers and fruit
• Most abundant and diverse group of plants
• Contain both male and female structures
• Bright petals, odors, and sugary nectar are used to attract pollinators
Plants Are the Basis of Land Ecosystems and Provide Many Valuable Products
• Nearly all organisms on land depend on plants for food
Plants• Plants have value when left in nature as well– Preventing runoff and erosion– Recycle carbon dioxide from the atmosphere– Produce oxygen to breath