Universiti Putra Malaysia Biology 1 ASB0204 Protist

BIOLOGY 1 ASB0204 Topic 11 Domain Eukarya 1: a) Protista DR SITI NOR ANI AZAMAN ERRA NOORFAZIRA BANDONG Biology Unit Centre of Foundation Studies for Agricultural Science Universiti Putra Malaysia...

BIOLOGY 1 ASB0204 Topic 11 Domain Eukarya 1: a) Protista DR SITI NOR ANI AZAMAN ERRA NOORFAZIRA BANDONG Biology Unit Centre of Foundation Studies for Agricultural Science Universiti Putra Malaysia 1 Outline 11.1: General Characteristics of Protista 11.2: Classification of Protista 11.2.1: Unique Characteristics of Algae 11.2.1: Unique Characteristics of Protozoa 11.3: Importance of Protista 2 Learning outcomes By the end of this lecture, you will be able to: 1. Describe the general characteristics of Protista 2. State the classification of Protista into two major phyla of algae and four major phyla of protozoa 3. Describe the unique characteristics of algae 4. Describe the unique characteristics of protozoa 5. State the importance of Protista 3  Protists vary greatly in organization Most are single-celled; and still others are multicellular. But, they are never multi-tissued They may manifest as filaments or colonies Not all protists are microscopic. Some group can be as big as 200 meter long. Common size are 5 μm to 2 or 3 mm Some are parasitic forms and a few free-living algal protists… Subtopic 11.1 General Characteristics of Protista 5  General Characteristics of Protista Members of domain Eukarya Algae, protozoa, water molds and slime molds are an informal group of primarily aquatic eukaryotic organisms with diverse body forms, types of reproduction, modes of nutrition, and lifestyles Protists in a drop of pond water 6  General Characteristics of Protista Diversity of Protist Morphological structure: – Like other eukaryotic cells, they have nuclei and other membrane-enclosed organelles such as mitochondria and plastids, 9 + 2 flagella, and multiple chromosomes Body plan varies considerably among protists: – Most are unicellular – Some form colonies – Some are coenocytic – Some are multicellular Most multicellular protists have relatively simple body forms without specialized tissues 7  General Characteristics of Protista Modes of Nutrition Most algae are autotrophic photosynthesizers Some heterotrophs obtain nutrients by absorption or ingest food Some protists switch their modes of nutrition; are autotrophic at certain times and heterotrophic at others = mixotroph Example: Euglena viridis ✔ Obtain energy from a variety of sources depending on environmental conditions - Photosynthesize in light - Hunt in dark 8  General Characteristics of Protista Interactions Many protists are free-living, but others form symbiotic associations with unrelated organisms – Mutualism, commensalism, parasitism Some parasitic protists are important pathogens of plants or animals Most protists reproduce asexually – many also reproduce sexually – No reproductive organs or embryos 9  General Characteristics of Protista Habitat Most protists live in the ocean, streams, lakes, and ponds Make up most of the plankton, and are the base of the food web in aquatic ecosystems Other aquatic protists attach to rocks or other surfaces and parasitic protists live in the other organisms’ body fluids Terrestrial protists are restricted to damp places such as soil, cracks in bark, and leaf litter 10 Subtopic 11.2 Classification of Protista 11  Classification of Protist Protist classification is evolving; two types of research contribute substantially to understanding phylogenetic relationships among protists – Molecular analysis of the gene for small subunit ribosomal RNA, and other nuclear genes – Ultrastructure data revealed by electron microscopy Diversity in ultrastructure and molecular data suggests protists are paraphyletic 12  Classification of Protist How eukaryotes Evolve? – Serial endosymbiosis hypothesis assumes certain organelles arose from symbiotic relationships between larger cells and smaller bacteria incorporated to live within them – Mitochondria may have originated as aerobic bacteria and chloroplasts may have originated as a cyanobacterium within a host cell 13  Classification of Protist Currently, protists and other eukaryotes are split into five informal supergroups: - Excavates - Chromalveolates - Rhizarians - Archaeplastids - Unikonts In this lecture, we will only focus on general informal group of Algae and Protozoa *Circled groups in figure indicates members belongs to either algae or protozoa 14 ▪ Two major groups: a) Algae: Plant-like protists (photosynthesis to make their food) http://protist.i.hosei.ac.jp/pdb/images/chlorophyta/ chlamydomonas/Euchlamydomonas/sp_15.html b) Protozoa: Animal-like protists (resemble animals in the way they get foods) https://saveourgreen.org/allpost/brown-algae/ https://www.livescience.com/5 4281-amoeba-definition.html http://lifeofplant.blogspot.com/2011/ 04/euglenoids.html 15 Algae Algae (singular, alga) are protists that contain chlorophyll and carry out photosynthesis Algae are either unicellular or colonial, the latter occurring as aggregates of cells. Filamentous algae : when cells are arranged end-to-end. The filaments may be branched or unbranched. Colonial algae Filamentous algae https://microbewiki.kenyon.edu/ind https://alchetron.com/Ulothrix ex.php/Volvox_carteri Habitat: salt or fresh waters or on the surface of most soil or rocks. 16 Algae Multicellular algae developed specialized tissues but they lack true stems, leaves or roots. The algal cells differ from protozoa by the presence of cell walls and vacuoles. Two major phyla: Phylum Chlorophyta (green algae) Phylum Phaeophyta (brown algae) 17  Phylum Chlorophyta (green algae) Most species are aquatic, but some are terrestrial and can be found in moist soils. Various species can be unicellular, multicellular, coenocytic (having more than one nucleus in a cell) or colonial. Contain chlorophyll a and b, and store food as starch in their plastids. Example: Chlamydomonas, Volvox. 18 https://mosys.univie.ac.at/research-and-teaching/topics/ clamydomonas-as-energy-resource/ Phylum Chlorophyta (green algae) E.g : Chlamydomonas ✔ Microscopic, green in color, round shaped ✔ Two flagella at anterior end. ✔ Eyespot; to receive light used to help direct its swimming. ✔ Cup shaped chloroplast contain pyrenoid where starch is synthesized. 19 https://www.istockphoto.com/illustrations/chlamydomonas Phylum Chlorophyta (green algae) E.g : Volvox ✔ Colonial green alga (loose association of independent cells) ✔ Hollow sphere, each cells resembles Volvox cell ✔ Some cells are specialized for http://www2.unb.ca/vip/photos.htm reproduction. Each can divide asexually to form new daughter colony within the parental colony Daughter colony leaves the parental colony by releasing enzymes that dissolves away the https://www.quora.com/How-can-you-determine-i portion of the parental colony f-volvox-is-multicellular,  Phylum Phaeophyta (brown algae) Many world’s familiar seaweeds are members of phaeophyte. They are photosynthetic and have chlorophylls a, c and carotenoids including fucoxanthin in their chloroplast. Example : Fucus https://www.researchgate.net/figure/Fucus-vesiculosus-photo-courtes y-of-Uli-Kunz_fig1_301325220 21 Phylum Phaeophyta (brown algae) E.g : Fucus ✔ Body (thallus), is plant like body that lacks true roots, stems and leaves: ✔ Consists of a blade or lamina, a https://www.marinespecies.org/photoga stipe and a holdfast llery.php?album=1033&pic=126889 ✔ Leaf like blade (or lamina); for photosynthesis. Flat and compressed forked frond with smooth edges that are dichotomously branched. ✔ Stem-like stipe: for support and withstand from wave action. ✔ Root-like holdfast: anchors the alga to maintain a firm foothold Racionero-Gómez, B. (2017). Rhenium, osmium and nitrogen 22 uptake in Phaephyceae macroalgae, Fucus vesiculosus. Phylum Phaeophyta (brown algae) E.g : Fucus ✔ Air bladders; provide Non-fertile tip buoyancy that keep fucus floating. So its photosynthetic tissues Air bladder are exposed to sunlight. Blade ✔ The tips of the fronds (stem-like) enlarge to Receptacle form receptacles. Each receptacles contains conceptacles, where the Stripe gametes are formed. Holdfast Racionero-Gómez, B. (2017). Rhenium, osmium and nitrogen uptake in Phaephyceae macroalgae, Fucus vesiculosus. 23 Protozoa Members of protozoans are unified as heterotrophic and some mixotrophic mode of nutrition. Generally motile; nearly all possess flagella, cilia, or pseudopodia that allow them to navigate their aqueous habitats. Strictly non-multicellular and exist as either solitary cells or cell colonies Protozoans have colonized a wide array of aquatic and terrestrial habitats from the Arctic and Antarctic to equatorial zones. 24  Classification of Protozoa Protozoa can be classified into four phyla as follows: a) Phylum Euglenophyta; Eg: Euglena b) Phylum Rhizopoda; Eg: Amoeba c) Phylum Ciliophora; Eg: Paramecium d) Phylum Apicomplexa; Eg: Plasmodium 25  Phylum Euglenophyta Small, Freshwater organisms. Most are photosynthetic. Some lacks of chloroplast therefore ingest or absorb their food. Has mitochondria and lacks cell wall. Special region of the chloroplast called pyrenoid, produces unusual type of carbohydrate called paramylon. Have two flagella (unequal length) https://www.carolina.com/teacher-resources/Interactive/c arolina-labsheets-introduction-to-protista-euglena/tr2600 and eyespot. tr Contractile vacuole remove excess water. 26  Structure of Euglena https://www.carolina.com/teacher-resources/Interactive/carolina-labsheets-introduction-to-protista-euglena/tr26008.tr 27 Phylum Rhizopoda Include protists that moves by means of Pseudopodia (Greek; False Feet) Use the pseudopodia to capture prey and for locomotion. Heterotrophic; Feeds on wide range of bacteria, algae and other protists Amoeba proteus is an example of Rhizopods 3 types of vacuole in amoeba ✔ Digestive vacuole – Helps in digesting food particles ✔ Contractile vacuole – Removes excess water to the outside of body so that amoeba does not burst ✔ Food vacuole - Formed as a result of the fusion of lysosomes and phagosomes. They perform different kinds of functions such as ingestion, storage, and excretion of excess water. 28 Phylum Ciliophora Most complex protozoan Example: Paramecium sp. Has fixed body shape Body of paramecium is covered by rows of cilia Cilia used for swimming, beat in synchronized pattern over the body surface. Ingest their food particle by sweeping into oral groove down a gullet and incorporated into food vacoules, soluble nutrients are absorbed by cytoplasm and eliminate wastes through anal pore Two different nuclei: 1. Macronucleus - metabolism and growth 2. Micronucleus – sexual reproduction 29  Phylum Apicomplexa A large group of parasitic, spore-forming protists Example: Plasmodium sp. Lack specific structure for locomotion; instead they move by flexing. Named after their apical complex of microtubule that https://www.scidev.net/asia-pacific/news/population-of- enable them to penetrate and monkey-malaria-parasite-1/ attach to the tissue of their host. 30 Subtopic 11.3 Importance of Protista 31  Roles in Biosphere (CO2 Fixation) Protist are major component of plankton as primary producers of aquatic ecosystem. They play basic role in food chain provide food & oxygen to other organisms: Phytoplankton (algae): fix carbon in sunlit surface waters via photosynthesis Zooplankton (protozoa): graze phytoplankton https://ecologyofchesapeakebay101.weebly.com/interactions-of-the-bay.html Carbon enters the planktonic food web; either to be respired for metabolic energy or accumulates as biomass or detritus 32  Food Source Seaweed are important source of food, that may be used to overcome food shortage in the world and provide essential nutrients; Example: Edible seaweed (Kelp) In Japan and Korea, Laminaria (brown algae) is used to make soup, and Porphyra (red algae) is used to wrap sushi. Spirulina provide essential nutrients such as vitamins, minerals, essential amino acids, carbohydrates and enzymes. 33 https://thefishsite.com/articles/the-multifunctional-dietary-properties-of-spirulina-and-its-use-in-aquaculture  Food Source Chlorella (unicellular; Phylum Chlorophyta) has high protein content as well as fats and vitamins. Research showed Chlorella promote growth and repair of body’s tissue. https://marinegenomics.oist.jp/gallery https://store.febico.com/pro ducts/biophyto-premium-chl orella-tablets-200mg 34  Eutrophication Eutrophication is a process whereby water bodies (lakes, estuaries, or slow-moving stream) receive excess nutrients that stimulate excessive growth of algae. Usually result with algal bloom or enhanced algal growth. Source of excess nutrient come from: a) Fertilizers applied to agricultural fields b) Erosion of soil containing nutrient c) Sewage treatment plant discharges https://ishii-eco.jp/english/ Algal bloom reduce dissolved oxygen in the water when dea plant material decomposes and this cause death of other 35 aquatic organisms.  Red Tides Common name for estuarine or marine algal bloom Caused by dinoflagellates of red algae Produce large quantities of neurotoxin that attack the nervous system and kills fish https://serc.carleton.edu/microbelife/topics/redtide/g eneral.html Human that eat shellfish that have fed on dinoflagellates may suffer paralytic shellfish poisoning ✔ Paralyzed respiratory muscle ✔ Death from respiratory failure occasionally occurs 36  Human Health The apicomplexan are among the most important phyla in this kingdom with respect to human health Genus Plasmodium of apicomplexan caused malaria in humans. The malaria parasite are transmitted to a host through the bite of an infected female Anopheles mosquito. https://www.cdc.gov/parasites/chagas/index.html Plasmodium infected human blood by vector of mosquito, Anopheles 37  References 1. Solomon, EP, Martin, CE, Martin, DW, Berg, LR (2019). Biology (11th Ed.). Cencage Learning. Chapter 26. Protist. Page 106-128. 1. Parker, N. P., Schneegurt, M., Hue Thi Tu, Anh, Lister, P., & M. Forster, B. (2024, January 10). Algae. Retrieved from https://openstax.org/books/microbiology/pages/5-4-algae 1. Laybourn-Parry, J. E.M. and Diaz,. Julia M. (2024, July 15). Protozoan. Encyclopedia Britannica. https://www.britannica.com/science/protozoan 39