Lecture 14 Some organelles were acquired by endosymbiosis Mitochondira primary symbiosis Chloroplast secondary endosymbiosis Having a chloroplast is not a synapomorphy Plants double membrane primary Protists three or more membranes secondary Chloroplast endosymbiosis occurred more than once Secondary symbiosis Organelle has three or more membranes Some protists Secondary endosymbiosis Domain Eukarya contains many different groups Protists Plants Animals Protists are no longer considered a kingdom Plants are autotrophic Animals are heterotrophic Poorly understood relationships Protists have several means of movement Cilia flagella Can direct food movement of materials Cilia are like short flagella Ex Paramecium Flagella example tail of sperm Moves like a whip made of microfilaments Cytoplasmic streaming pseudopods Membranes What Diatoms do Move by microfilaments inside shells Still not fully understood Protists can use vacuoles to regulate water Contractile vacuole Use vacuole to expel water back into the environment Too much water coming in can cause the cell to burst Slowly extending plasma membrane and then flowing into those extensions Very controlled and directed Can also use pseudopods for phagocytosis Ex Ameoba Hypertonic Organisms living in freshwater Don t have cell walls so water is coming into their bodies Protists can use vacuoles for digestion Endocytosis Brings food particles into body What is the acid doing Helps with digestion in vacuoles Protists vary in morphology and can be multicellular Multicellularity and specialization Some protists can look like they are multicellular even though they are colonial Many single celled organisms working together Cells of single organism devote energy to different tasks Diversification of function in an organism Once it becomes multicellular Protists have many lifestyles Marine and autotrophic Freshwater autotrophic and heterotrophic Can be both auto and hetero only some Terrestrial Parasitic Ex Malaria Endosymbionts Sapbropes Most animals do not contain anything to break down cellulose Use protists to digest cellulose with the enzyme cellulase Protists serve many ecological roles Fix 1 5 of the Earths carbon Produce a bunch of oxygen Food for other organisms Pathogenic Sands of beaches Commercial value Crude oil Pesticides Cleaning products Ex African Sleeping Sickness Giardia STD s Protists can be endosymbionts Endosymbiosis Mutualism Two organisms living together one living inside endo Both organisms benefit Commensalism One benefits and one does not but isn t harmed Parasitism One benefits and one is harmed Most endosymbiotic protists are microbial Extremely small organisms Symbionts of plants or animals Trichonympha lives inside termite and breaks down cellulose Photosynthetic symbionts Coral take up a protist that can synthesize gives coral its color If the protist dies the coral dies Protists can be pathogenic Many clades Diseased include Trichomoniasis STD Giardisis Backpackers diarrhea Prevent water reabsorption Malaria Trypanosomiasis Lives with red blood cells Toxoplasmosis Carried in cat feces Can kill fetus if it gets inside pregnant mother Can lead to schizophrenia behavioral changes Primary amebic meningoencephalitis Kills within 24 hours Gets through blood brain barrier and eats brain Using netty pot without distilled or boiled water In stagnant water Protists can have negative environmental effects Algal blooms Red tides dinoflagellate blooms Avoid oysters in any month that doesn t have an R in it Produced by dinoflagellate Prevents sodium channels from opening Chlorphyll pigment Nerve toxins Other blooms Prevent light from penetrating water Potato blight Can kill other organisms Light powder that blocks tracheae of insects Protists have commercial value Diatomaceous earth diatoms Filter insectisides Emulsifiers align carrageenan Ice cream cosmetics Medical uses Cervical dilator Blade of brown algae Parasitic on crops Late blight Irish potato famine Prostists reproduce asexually and sexually Mitosis budding binary and multiple fission Meiosis evolved early in protists Sexual reproduction Will involve meiosis Conjugation is an example of sex without reproduction Micronucleus is the typical nucleus Macronucleus contains many copies of genetic info but is packaged into units containing very few genes Process Micronucleus undergoes meiosis disappear remaining one goes through mitosis Switches with other Life cycles All stages that are used to produce offspring Animals simple life cycles Protists plants fungi complex life cycles Plants and protists diplontic aka alternation of generations Gametophyte and sporophyte Protists multiple hosts Reproduction can require multiple hosts Plasmodium Sexual reproduction inside mosquito stomach Male and female gametes fuse together and form cyst Only time in life cycle when diploid Asexual reproduction in liver Form male and female gametes waiting to be picked up by new host Protists are not monphyletic Some lineages are Sister groups to plants and animals 5 or 6 protists groups Aveolates Have alveoli Flattened vesicles beneath plasma membrane Asexual and sexual reproduction Apicomplexans dinoflagellates ciliates Stramenopiles Two flagella hairy and smooth Photosynthetic Unicellular or multicellular Brown algea diatoms oomycetes Can reproduce sexually or asexually Use laternation of generations Excavates Many pathogens Some no mitochondria Secondary symbiosis Endosymbiosis where they obtain chloroplasts Have flagella some Reproduction mainly by binary fission Can be autotrophic or heterotrophic Rhizaria Skinny pseudopods External shells tests Tests are made of calcium carbonate or cilica Pseudopods extend from tests Source of limestone Pseudopodia can have multiple functions Floating gas exchange eating Unikonts Amoebozoans Phagocytosis lope shaped pseudopodia Used for movement and feeding Slime molds loboseans Slime molds have the ability to move Unikonts Choanoflagellida Single flagellum and a collar Flagella beats moving water around Traps food inide collar They are heterotrophic and often colonial Sister group to animals Plantae Green algae are the sister taxa to land plants Peptidoglycan Pigments For photosynthesis Mostly chlorophylls Pigment depends on type of plant Green algae are the sister group to land plants Chlorophyll b and starch storage Streptophytes Land Plants Ch 28 29 Aquatic Algae protist Retention of egg Look at Fig 28 1 Glaucophytes are the most primitive