Presentation on theme: "Honors/Gifted Kingdom Protista Chapter 19. What is a Protist? Classified in Kingdom Protista “Protista” means “very first” Loosely related group of micro."— Presentation transcript:
What is a Protist? Classified in Kingdom Protista “Protista” means “very first” Loosely related group of micro orgs. Believed to evolved 1.5 billion years ago Why is this name fitting? Protists are the simplest Eukaryotes Nucleus and Membrane Bound Organelles Evolutionarily – could have been “ancestor” eukaryote organism
Protist Reproduction Can be sexual or asexual When would asexual be better? Sexual?
Classification Kingdom Protista – All Protists Problem to classify because of diversity Classified further by mode of nutrition 1. Animal Like Protists - Heterotrophic Must EAT their food Move around like animals Unicellular UNLIKE Kingdom Animalia 2. Plant Like Protists - Autotrophic MAKE their own food Lack organs/parts UNLIKE Kingdom Plantae 3. Fungal Like Protists – Decomposers/Parasites ABSORB their food externally. Lack chitin and have centrioles UNLIKE Kingdom Fungi
Animal-Like Protists Once called Protozoans –“First Animals” Make up 70 Percent of all Human Parasites Why not animals? Unicellular! 4 Phlya of Animal-Like Protists Based on how they move 1. Zooflagellates use flagella to move 2. Sarcodines move by extension in cytoplasm 3. Ciliates use cilia to move 4. Sporozoans do not move at all
1.Zooflagellates (Phylum Zoomastigina) Swim using flagella Whiplike tails “Eat” food through cell membranes Ex: Trypanosoma – African Sleeping Sickness Ex: Dileptus Parasitic or free living Can use asexual and sexual life cycles
2. Sarcodines (Phylum Sarcodina AKA Phylum Rhizopus) Obtain food and moves by projections of cytoplasm called pseudopods Ameoboid movement – streaming movement of cytoplasmic projections Contractile Vacuole – controls water in cell Food vacuole – holds food Ex: Ameobas Ex: Entameoba causes amebic dysentery
Sporozoans Other infectious parasites Giardia lambalis- diarrheal illness caused by a microscopic parasite usually found in water associated with animal feces Cryptosporidium – diarrheal illness associated with animal feces; mass outbreaks occur after floods (over 400,000 after the Milwaukee floods of 1993) Toxoplasma gondii - parasite that reproduces in cats and is released in their feces; can infect humans. Effects include miscarriages, psychology, and higher ratio of male births!
Ecology of Animal Like Protists Not so Good: Can be parasitic/cause disease Malaria, African Sleeping Sickness, Cryptosporidium Good: Symbiosis Termites have beneficial animal like protist called Trichonympha in their stomachs Break down cellulose in wood so termites can use it as food
Let’s take a closer look at Paramecium caudatum Paramecium VELA & Questions
Article: Cat Parasite May Affect Cultural Traits in the Human Population
Fungus-Like Protists Fungus-like protists are heterotrophs that absorb nutrients from dead or decaying organic matter. Unlike true fungi, however, fungus-like protists have centrioles and lack chitin in their cell wall. The fungus-like protists include: 1. Cellular slime molds 2. Acellular slime molds 3. Water molds
1. Cellular Slime Molds Cellular slime molds belong to the phylum Acrasiomycota. Spend their life as an independent individual that feeds, grows, and divides by cell division During harsh times, individuals can form large slug-like MULTICELLULAR colony with a distinct cell membrane to reproduce.
Cellular Slime Molds in Action http://www.princeton.edu/main/news/a rchive/S26/40/20I71/index.xml?sectio n=mm-featured
2. Acellular (Plasmodial) Slime Molds Acellular slime molds belong to the phylum Myxomycota. During the course of their life cycle, their cells fuse to produce structures with many nuclei known as plasmodia (a mass of cytoplasm that contains many diploid nuclei but no cell walls or membranes). THE MOVING, FEEDING FORM OF A PLASMODIAL SLIME MOLD IS A MULTINUCLEATE BLOB OF CYTOPLASM – THIS IS THE FEEDING STAGE OF THE LIFE CYCLE
3. Water Molds Water molds are members of the phylum Oomycota. They thrive on dead or decaying organic matter in water and are plant parasites on land.
Ecology of Fungi Like Protists Slime molds and water molds are MOST important recyclers of organic material Some can be harmful Plant diseases ex. Irish Potato Famine – water mold Phytophtora infestans *overgrowth of water mold caused by wet and cool conditions Why is the earth not littered with dead orgs? Tissues broken down by Fungi Like Protists and other decomposers
Plant Like Protists Main Characteristic: Chlorophyll Green Pigment- traps light, carries out photosynthesis Evolved from symbiosis of photosynthetic bacteria and larger, heterotrophic bacteria Commonly called “Algae” Many contain cell wall like plants Lack plant organs/parts Classification Unicellular – unique characteristics – 4 phyla Multicellular – type of pigments (color) – 3 phyla
1. Phylum Euglenophyta Euglena- plantlike unicellular algae w/ animal like characteristics Animal – like – can be heterotrophic, gullet, flagella Plant – like – chloroplasts, starch storage, eye spot Cluster of reddish pigments known as an eyespot which function to help find sunlight for photosynthesis Euglenas do not have a cell wall, but they do have a pellicle. Euglenas reproduce asexually-binary fission Why plant-like? Chloroplasts!
2. Phylum Pyrrophyta - Dinoflagellates Dinoflagellates are unicellular plant-like that can be photosynthetic or heterotrophic 2 flagella wrapped around in grooves between 2 thick plates of cellulose that protect the cell Most reproduce asexually by binary fission Many species are bioluminescent – fire algae Can have red, green or yellow pigments Can produce neurotoxins - Red Tide
Algal Blooms -Unicellular plant like protists can grow rapidly in areas where sewage is discharged. -These rapid growths are known as algal blooms. -Algal blooms quickly deplete the water of nutrients, and the cells of the bloom begin to die in great numbers. -Decomposition of these dead algae can rob water of its oxygen, choking its resident fish and invertebrate life --Ex: Red Tide
3. Phylum Chrysophyta – Golden Algae Members of the phylum Chrysophyta are a diverse group of plantlike protists that have gold-colored chloroplasts/pigments. includes yellow-green algae and golden-brown algae reproduction can be sexual or asexual colonial Store food as oil not starch
4. Phylum Bacillariophyta - Diatoms Unicellular plant-like protists that produce thin, delicate cell walls rich in silicon – glass like Variety of photosynthetic pigments Among the most abundant organisms on Earth! Make LOTS of Oxygen! Found in toothpaste, filters Bioluminescent
Multicelled Algae Chlorophyll & Acessory Pigments Multicellular Plant Like Protists are classifed by type of photosynthetic pigments they contain. In adapting to conditions of limited light, various groups of algae have evolved different forms of chlorophyll: Chlorophyll a Chlorophyll b Chlorophyll c Each form of chlorophyll absorbs different wavelengths of light: Accessory pigments that absorb light at different wavelengths than chlorophyll.
Multicellular Plant-Like Protists: Red, Brown, and Green Algae The 3 phyla of algae that are largely multicellular are commonly known as: 5. red algae 6. brown algae 7. green algae A major difference among these phyla are their photosynthetic pigments.
5. Phylum Rhodophyta – Red algae Live at great depths due to their efficiency in harvesting reddish accessory pigments called phycobilins phycobilins absorb blue light (reflect red) Most red algae are multicellular and can live in waters from the polar regions to the tropics Carageenan – red algae compound in foods – “gel” Example: Chondrus crispus (irish moss)
6. Phylum Phaeophyta – Brown Algae Brown algae contain chlorophyll a and c, as well as a brown accessory pigment, fucoxanthin (foo-co-zan-thin) All brown algae are multicellular and most live in cool, shallow, coastal marine waters. Examples: giant kelp, Sargassum, and Fucus
7. Phylum Chlorophyta – Green Algae Green algae share many characteristics with plants, including their photosynthetic pigments and cell wall composition: have cellulose in cell wall contain chlorophyll a and b store food in the form of starch Green algae can be found in fresh or salt water: Some are single cells (ex: Chlamydomonas) Some form colonies (ex: Volvox) Some are multi-cellular (ex: Ulva)
Green Algae Chlamhydomonas unicellular green algae Volvox colonial green algae Ulva multicellular green algae Spirogyra Multicellular green algae
Ecology of Plant-Like Protists Produce 90% of all oxygen on earth! Phytoplankton = bottom of food chain Human foods Ice creams Chocolate Sushi Plastics Waxes Paints Agar Can release toxin & choke environment – algae bloom
Protist Graphic Organizer Kingdom Protista Fungi-like Absorb food Animal-like Eat food Plant –like Photosynthetic unicellmulticell Create a graphic organizer on your sheet Fill in the phylum names under plant, animal and fungi-like…under each phylum, give an example
Honors/Gifted KINGDOM FUNGI Ch 20 “NO, THEY ARE NOT PLANTS”
What is a fungus? (answer this question in your own words)
General Characteristics of Fungi Ubiquitous Decompose HETEROTROPHIC Some are parasitic, some are mutualistic Have plant & animal characteristics PLANT-Like = many are anchored in the ground; cell walls (but NOT of cellulose) ANIMAL-Like = Heterotrophic On the living and on dead Parasites Saprobes
Fungi General Characteristics Mostly multicellular Yeast unicellular They have a nucleus Many have multiple nuclei Much of their lifecycle is haploid! They have a cell wall Made of chitin – a protein/carb complex Digestion is EXTRACELLULAR! They secrete an enzyme that breaks down nutrients THEN they take them in NO PHOTOSYNTHESIS!
FUNGI STRUCTURE Made of thin filaments = hyphae (fuzzy) Hyphae can grow as individual cells or may fuse together to form coenocytic threads there are different types of hyphae some for reproduction, some for growth, some for stability (sturdy) Hyphae that form a web and work together = Mycelium
More about their structure…. The visible part of a fungus is only a very small part of the mycelium…. ….most is underground
FUNGI REPRODUCTION Some reproduce asexually, some sexually – most both Asexual reproduction Fragmentation/budding, Spores (clones) Spores can be thick walled & resist water loss (ie, the fungus won't dry out) Sexual reproduction haploid +/- hyphae fusion diploid gametangium meiosis haploid spores haploid organism
Classification 4 Phyla 1. Zygomycota 2. Ascomycota 3. Basidiomycota 4. Deuteromycota* --All have different hyphae types & reproductive structures -- Classified based on how they reproduce!
1. Phylum Zygomycota “Zygote fungi” Reproduce sexually & asexually Formed from 2 different gametangium that fuse Gametangium zygospore Ex. Bread Mold, Athlete’s foot (Tinea pedis)
Zygomycota Hyphae a) Rhizoid Anchor the fungus in its food source b) Stolon Run along the surface of the food source Give rise to 2 mating forms (“+” and “-”) Sexual reproduction & growth c) Sporangia Also called “fruiting bodies” Swell at the tips of sporangiophores Contain the spores used for asexual reproduction
Phylum Ascomycota Sac fungi Reproduce sexually & asexually Spores (called ascospores) are made in a sac is called an ascus Conidiophores form and help disperse haploid spores Important fermenters Convert sugar to CO 2 & alcohol Ex. Yeasts (with no hyphae), powdery mildews, food molds Yeast = only unicellular fungus! Infectious: candidiasis, ringworm
Phylum Basidiomycota Club fungi Reproduce sexually & asexually Forms a club shaped structure = Basidia; this is where spores are made = Basidiospore Cap = where reproduction takes place Ex. Mushrooms, puffballs, smuts
Penicillin 1928, Sir Alexander Fleming observed that colonies of the bacterium Staphylococcus aureus could be destroyed by the mold Penicillium notatum
Aspergillus Can cause severe lung infection Can form endospores 2-4,000 year old endospore of Aspergillus niger may have caused the death of initial archeology team members excavating tombs
MUTUALISTIC FUNGI 2 types a) Lichens b) Mycorrhizae
a) Lichens SYMBIOSIS of a fungus (usually an ascomycetes) with an algae OR a cyanobacteria The fungal partner benefits by getting sugars, its only nutrients, from the algae which photosynthesize. The algal partner gets protection and nutrients broken down by the fungal partner.
b) Mycorrhizae Fungus & Plant Hyphae grow on roots of plant How does each benefit?
QUIZ TIME Answer Questions - True or False…if false CORRECT it! 1. Fungi are autotrophs (use photosynthesis). 2. Fungi spend much of their lives in a haploid state. 3. There are 3 Phyla of Fungi. 4. Fungi have cell walls made of cellulose. 5. Fungi are made up of special cells called hyphae.
QUIZ TIME – Answers! 1. Fungi are autotrophs (use photosynthesis). F 2. Fungi spend much of their lives in a haploid state. T 3. There are 3 Phyla of Fungi. F 4. Fungi have cell walls made of cellulose. F 5. Fungi are made up of special cells called hyphae. T