Chapter 21- Protists & Fungi Honors Biology

I. Protist Classification A. The 1 st Eukaryotes 1. Part of the kingdom Protista 2. Placed in the kingdom Protista when they cannot be classified as a plant, animal or fungus 3. Most are unicellular a. Example of a multicellular protest: brown algae or kelp 4. It is very difficult to classify protists 5. The ancestors of modern day protists gave rise to all plants, animals & fungi

II. Protist Structure & Function A. Movement 1. Amoeboid Movement a. Move by changing their shape and using cytoplasmic extensions called pseudopods b. ex. Amoeba Amoeboid Movement Amoeba

2. Cilia & flagella a. Protists that move using cilia are called ciliates b. Protists that move using flagella are called flagellates Flagella & Cilia Movement Euglena Paramecium

3. Passive Movement a. Nonmotile b. Depend on water or air currents to carry around their reproductive cells (spores) c. Ex. Plasmodium forms spores which are carried by mosquitoes & causes malaria Plasmodium Life Cycle

B. Reproduction 1. Cell Division a. Asexual reproduction/ mitosis b. Allows rapid reproduction c. Identical cells d. Limits genetic diversity e. Ex. Amoebas, paramecium, ciliates

2. Conjugation a. After conjugating, the protist will go through mitosis b. Not a type of reproduction c. Maintains or Increases genetic variation d. Promotes evolution

3. Sexual Reproduction: Alternation of generations a. alternates between a haploid & diploid phase b. Water mold produces sexually by forming male & female structures that produce gametes  fertilization  zygote c. Water mold reproduces asexually by producing spores in a structure called a sporangium

III. Ecology of Protists A. Autotrophic Protists 1. Very different, but all are photosynthetic 2. Base of the food chain for aquatic life 3. Phytoplankton- feeding fish and whales

4. red algae- support the coral reefs by providing nutrients from photosynthesis - provides the calcium carbonate needed to stabilize the growing coral reefs 5. brown algae- largest protist, provides shelter for many marine species, provides food 6. euglenas- recycle waste from sewage discharge a. If there is a large amount of waste, an algal bloom may develop b. Dinoflagellates cause a bloom called a “red tide” when they release toxins into the water

B. Heterotrophic protists 1. Amoebas a. Capture their food in way very similar to endocytosis b. Store their food in a food vacuole c. Digest their food rapidly

2. Ciliates- paramecium – pg. 612 a. Use their cilia to sweep food into their gullet b. Digested by lysosomes c. Wastes removed through the anal pore

3. Slime Molds a. Eats decaying matter b. Found in damp places c. Play a key role in recycling nutrients d. 2 life stages » Single amoeba-like cells » Group of cells come together and form a structure know as plasmodium

4. Protists that Absorb a. Water molds grown on dead matter and absorb food molecules through their cell walls

C. Symbiotic Protists 1. Mutualists a. Both the protist & the host benefit b. Trichonympha lives in the digestive system of termites and allows for the digestion of wood

2. Parasites and Disease a. Intestinal Diseases » Water borne » Giardi: causes severe diarrhea & digestive problems » Entamoeba: causes amebic dysentery, destroys intestines & causes severe bleeding

b. African Sleeping Sickness » Caused by the protists Trypanosoma » Spread by the tsetse fly » Destroys blood cells and damages nerves cells » Causes nervous system damage and causes the person to go into deep, fatal sleep

c. Malaria » Caused by Plasmodium » One of the world’s most serious diseases » Carried by a mosquito & humans

IV. Fungi A. Characteristics 1. Heterotrophic a. Contain powerful enzymes that digest food outside their bodies b. Then they absorb the nutrients 2. Cell wall contains chitin 3. Eukaryotic

B. Structure & Function 1. Yeast are unicellular 2. Most other fungi are Multicellular a. Contain branching fibers called hyphae b. The portion of the fungus that is above ground is the fruiting body c. The mass of branching hyphae beneath the soil is the mycelium ( root like structures)

C. Reproduction- pg Asexual a. Release spores into the wind & water b. Budding or breaking off a hypha is also considered asexual reproduction 2. Sexual a. Involves 2 different mating types » No male & female, just “+” and “-“ b. Hypha of opposite matting types meet & fuse to form a 2N zygospore c. Zygospore goes through meiosis and produces haploid spores that can all make new mycelium

D. Major Phyla of Fungi 1. Basidiomycota a. Club fungi b. Sexual spores found in a club shaped cell called a basidium c. Ex. Mushrooms, puffballs, earthstars, shelf fungi, jelly fungi, rusts

2. Ascomycota a. Sac fungi b. Sexual spores are found in a sac-like structure called an ascus c. Ex. Morels, truffles, Penicillium species, yeast

3. Zygomycota a. Common molds b. Tough zygospore produced during reproduction that can stay dormant for long periods c. Ex. Black bread mold, mycorrhizae on plant roots

4. Chytridomycota a. Chytrids b. Only fungi with flagellated spores c. Ex. Decomposers in lakes and moist soils

E. Ecology of Fungi 1. Decomposers a. Help ecosystems maintain homeostasis by recycling elements & breaking down dead organic matter 2. Parasitism a. Plant Diseases » Corn Smut » Wheat rusts » Mildews » Destroys approx. 15 % of the crops in temperate climates

Corn Smut Wheat Rust Mildew

b. Animal Diseases » Cordyceps- infects living animals & digests the cells and tissues until the animal dies » Candida albicans- yeast infection in humans, thrush (mouth), athletes foot

3. Lichens a. mutualistic relationship with cyanobacteria or algae b. cyanobacteria or algae give the fungus energy (glucose) c. fungus gives the cyanobacteria or algae water & minerals d. lichens are great indicators of pollution levels in an environment due to their high sensitivity of air quality

4. Mycorrhizae a. Mutualistic relationship with plant roots b. Fungal hyphae collect water & minerals and bring them to the roots c. Fungi releases enzymes that free nutrients in the soil d. The plants provide the fungus with energy from photosynthesis