Kingdom Protista Protists Kingdom Protista The kingdom Protista

Kingdom Protista Protists

Kingdom Protista • The kingdom Protista includes eukaryotic organisms that don’t belong in one of the other eukaryotic kingdoms (Plantae, Animalia, or Fungi) – These organisms share traits with these other groups; just not enough to be classified with them

Kingdom Protista • Protists can be singlecelled or multicellular organisms. • All protists are eukaryotes. • Groups of Protists: – Protozoa (Animal-like) – Algae (Plant-like) – Fungus-like forms

Examples of Protists • Includes: Amoeba, Naegleria fowleri Flagellate, Giardia lamblia Ciliate, Strombidium – – Amoebas Ciliates Flagellates Algae

Protozoans • Protozoans: animal-like protists – These protists share characteristics with animals such as: • Feed on other organisms • Cells lack cell walls – Examples: • A) Zooflagellates – Move around using flagella • B) Sarcodines – Move using pseudopods (“false feet”) – Amoebas • C) Ciliates – Move using cilia: short hair-like projections • D) Sporozoans – Do not move on their own – Are parasitic Ciliate

Algae • Algae: plant-like protists – These organisms share characteristics with plants such as: • Photosynthetic • Cells contain cell walls – Examples: • A) Phytoplankton – algae that live near the surface of the ocean. • B) Red, brown or green algae • C) Diatoms – have silicon in their cell walls) Diatoms

Algae • Besides oxygen production, algae are used by humans for many other purposes: – A) Food • seaweed & kelp are edible (Sushi anyone? ) – B) Production of agar • Gelatin-like substance that has many uses – C) Used to make toothpaste “pasty” – D) Others?

Fungus-like Protists • Like fungi, these are usually decomposers. – Absorb nutrient from dead or decaying matter Slime Mold • Fungus-like protists do not have chitin in their cell walls like true fungi do. – Slime molds – Water molds

Kingdom Fungi

Kingdom Fungi • Eukaryotic organisms that primarily feed on dead or decaying matter. – Grow on their food source – Secrete enzymes that digest their food outside their bodies – Absorb nutrients through their cell walls • Can be multicellular (mushrooms, molds) or unicellular (yeasts)

Role of Fungi in Ecosystem • Fungi are called “The Great Decomposers” – Breakdown organic material and recycle it in nature • Fungi also form mutualistic relationships with other organisms – Ex: mycorrhizae • Mutualistic relationship between algae and a fungus – Algae makes food & fungus provides minerals

Characteristics of Fungi • Fungal Structures – Have cell walls, made up of chitin, a carbohydrate that also makes up the exoskeleton of insects. – Hyphae: thin filaments that make up most fungi. – Mycelium: many hyphae tangled together that help the fungus absorb food. • Typically grow under the surface – Fruiting Body: the reproductive structure of the fungus (Example: mushrooms)

Characteristics of Fungi Fruiting Body Spores

Types of Fungi • Mushrooms – Multicellular, most complex of fungi • Molds – Multicellular – Not usually visible until fruiting bodies appear • Yeast – Unicellular, simplest form of fungi

Fungal Reproduction • Reproduce both asexually and sexually. • Asexual Reproduction: – Hyphae break off and begin to grow on their own. – OR, fungus produces spores that are released and can grow on their own. Mold spores

Fungal Reproduction • Sexual Reproduction: Requires fungi of two different mating types, called either + (plus) or – (minus) – When a + hyphae and a – hyphae meet, they fuse together. – The fused hyphae grow and form a diploid zygote, which then will go through meiosis. – Meiosis produces haploid spores, which are able to grow on their own.

Uses of Fungi • Humans use fungi for a variety of purposes: – A) Food • Edible mushrooms, yeast (make bread) – B) Food production • Certain fungi can be used to flavor foods (ex: the “bleu” in bleu cheese – C) Biotechnology – D) Medicines • antibiotics

Parasitic Fungi and Fungal Disease • Most fungi that cause disease in humans are opportunistic pathogens, meaning they only infect people with weakened immune systems. – Ex: athlete’s foot, ringworm, jock itch, etc. • Most parasitic fungi infect insects and plants, many times killing their host.