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PROTISTS n Eukaryotic cells having a discrete membrane-bound nucleus (see Page 420) n Contain organelles (ribosomes, mitochondria, & lysosomes) n Most are unicellular and found in fresh or salt water. n Incredible biodiversity…occupying almost every niche and habitat.
Three Distinct Groups 1. Plant-like Protists 2. Animal-like Protists 3. Fungi-like Protists
Plant-like Protists – Organisms contain chlorophyll (autotrophs) – Can also absorb nutrients during dark times (heterotrophs) – Most plantlike protists reproduce asexually by MITOSIS. EUGLENA
Animal-like Protists n n n Heterotrophs (engulf or absorb food) Reproduce asexually by BINARY FISSION or sexually by CONJUGATION Occupy a diverse range of moist habitats. Locomotion: cilia or flagella Sporozoans and Malaria (see handout) Amoeba – Feeds by Phagocytosis
The Malarial Parasite's Life Cycle Plasmodium
The Malarial Parasite's Life Cycle
The Malarial Parasite's Life Cycle
Fungi-like Protists Also referred to as Slime Moulds n Prefer cool, shady, moist places and are usually found under fallen leaves or on rotting logs. n Most fungi-like protists reproduce sexually through meiosis and SPORE FORMATION n
The Importance of Protists Provide the critical base to most food webs. n Zooplankton; animal -like protists. n Phytoplankton; plant-like protists. n Eg. Algae - 80% of world’s oxygen n
Kingdom Fungi n n n Common Examples: Moulds, yeasts and mushrooms. Heterotrophic Saprobes – absorb their food from decaying matter Bodies of most fungi consist of hyphae – threadlike filaments (attached to a substrate) Fungi have cell walls made of chitin Hyphae branch, forming a tangled mass called mycelium
Fungi Reproduction Asexually: Fragmentation and Budding n Sexually: Spores. n Often the only visible portion of the fungi are its reproductive structures. (see spore diagram) n SPORES
Reproduction BUDDING YUMMY!!
One Deadly ‘Shroom! n Amanita phalloides is the most poisionous of all mushrooms. n Other mushrooms have hallucinogenic properties (such as the drug psilocybin) important in native religious rituals in Central and South America.
Kingdom Plantae Characteristics: n Lack mobility n Eukaryotic, multi-cellular, have tissues n Photosynthesis n Cell walls contain cellulose n May or may not have vascular tissue: tissue that conducts/transports water and nutrients (xylem and phloem) n Plants originated in water and since have been evolving for life on land
Plant Kingdom Non-vascular plants Seedless plants “naked” seeds (gymnosperms) Vascular plants Seed plants enclosed seeds (angiosperms)
Asexual Reproduction n MITOSIS n Runners, cuttings, grafting etc.
Sexual Reproduction ~Alternation of Generations~ See Page 435 Sporophyte generation Gametophyte generation Diploid = 2 sets of chromosomes Haploid = 1 Set (gamete)
Similarities and Differences Between Plants and Fungi Similarities: n n n Cells are eukaryotic Numerous Organelles Have cell walls Most anchored in soil or other substrate Reproduction can be asexual, or both Stationary Differences: PLANTS Most are autotrophs Starch is the main storage Most have roots Have cellulose in cell walls Some reproduce by seed FUNGI Are Heterotrophs Have few or no storage molecules Have no roots Often have chitin in cell walls None reproduce by seed
Kingdom Animalia Cell membrane n Heterotrophic n Must coordinate their activities n – – – Avoid predators Grow Reproduce
Bilateral and: if. Radial – Bilateral symmetry one half of Symmetry a shape is the mirror image of the other half. Eg. Humans – Radial symmetry: if shape of one part is repeated a number of times about a central axis. Eg. Starfish
Invertebrates n n n Zoology: study of animal life Multicellular Eukaryotic Heterotrophs that do not have a notochord (skeletal rod of connective tissue that runs lengthwise along dorsal surface and beneath nerve cord). No backbone.
Worm – Like Animals n Eg. Tapeworms
Arthropods Jointed appendages n Chitin exterior n Spiders, insects, crustaceans n
Vertebrates – Internal Skeleton n n Multicellular Eukaryotic Heterotrophs that have a notochord at some stage in their life. Backbone. Amphibians, Reptiles, Mammals, Fish, Birds.
Animal Reproduction Stations n Go from station to station and examine the various specimens. n Use your text to fill out the worksheet!
Phylum Cnidaria Jellyfish Sting!!!