Protists
Protozoa
• Move independently• Heterotrophic – obtain nutrients by ingesting
small molecules or cells.• Food vacuoles – where food is broken down
in.• Zooplankton – organisms that are the primary
source in aquatic ecosystems.
Reproduction
• Binary fission – division into two identical individuals.
• Multiple fission – division into more than two identical individuals.
• Conjugation – sexual reproduction, protozoa pair and exchange genetic material.
Classification
• Four Phyla:• Sarcodina – pseudopodia– Amoeba, radiolaria, naegleria
• Ciliophora – cilia– Paramecium, tetrahymena, blantidium
• Zoomastigina – flagella– Giardia, trypanosoma, leishmania, trichonympha
• Sporozoa – no locomotion, some parasitic– Plasmodium, toxoplasma
Tetrahymena
Plasmodium
Trichonympha
Naegleria
Giardia
Adaptations• Eyespot – detect changes in the quantity and
quality of light.• Some protozoan sense physical and chemical
changes or obstacles in their environment.• Cyst – dormant form, hardened external
covering, metabolic activity stop. Allow them to survive harsh conditions.
• Conditions are favorable protists emerge from cyst.
Evolution
• First prokaryotes evolved 3.5 billion years ago.• 1.5 billion years ago first eukaryotic organisms
evolved.• Protozoa descended from these early
eukaryotes.• Endosymbiosis
Fungi
• Objectives:– Describe the origin and evolution of fungi– Compare fungi with other eukaryotic organisms.– Describe how fungi obtain nutrients.– Distinguish between a hypha and a mycelium.
Characteristics
• Most fungi are:• Molds – tangled masses of filaments of cells.
• Yeasts – unicellular organisms, circular.• Hyphae – filaments of fungi.• Chitin – cell walls of hyphae. (unique to fungi)
Armillaria
• Lives underground• Occupies a space of 861,000 ft2
Ingestion
• Fungi secret enzymes to break down food then absorb the digested nutrients through their cell wall.
• Most fungi are saprophytic – live on organic compounds that they absorb from dead organisms in the environment.
Structure of Fungi• Mycelium – mat of hyphae visible to the
unaided eye.• In some fungi hyphae is divided by cross
section called septa. • Coenocytic – hyphae of species that do not
have septa.
Three Phyla of Fungi
• Zygomycota – coenocytic hyphae, spores.– Penicillium, mucor, rhizopus
• Basidiomycota – septate hyphae, reproduce sexually.– Puccinia, ustilago (mushrooms)
• Ascomycota – septate or unicellular hyphae, budding, spores– Yeast, morel
Molds
-fuzzy growth, spore-producing.-the hyphae of molds grow into the food, digesting it as they grow.
Ex.) athlete’s foot, used in making cheese, bread mold, dutch elm disease, penicillin (antibiotic fights bacteria),
18
Mushrooms Cap – where the spores are contained.
Stalk – where the cap grows from.
17
Yeasts, Truffles
- Single-celled fungi.
- Grows on: sap of plants, animal tissues, shower curtains, human skin.
- Used in food: bread, beer
- Reproduces by budding.19
Fungi as a Food
• Truffles• Very expensive.
• Fungus in man’s face
• Homework: worksheet
• Bonus: bring in pond water, carageenan label