Invertebrate Protozoa PDF

Invertebrate BIOZ 341  Kingdom: ANIMALIA PROTOZOA METAZOA kingdom : Prototista Eg : Ameoba PARAZOA EUMETAZOA PHY : PORIFERA Eg :...

Invertebrate BIOZ 341  Kingdom: ANIMALIA PROTOZOA METAZOA kingdom : Prototista Eg : Ameoba PARAZOA EUMETAZOA PHY : PORIFERA Eg : Sponges DIPLOBLASTIC RADIATA TRIPLOBLASTIC PHY : COELENTERATA BILATERIA Eg : Hydra Acoelomata Pseudocoelomata EUCOELOMATA Phy : Platyhelminthes Phy : Aschelminthes(nematoda) Eg : Ascaris Phy : Phy : Phy : Phy : PHY : Annelida Arthropoda Mollusca Echinodermata CHORDATA  Introduction To Invertebrates The animals without a vertebral column are called invertebrates and those with one are referred as vertebrates. The invertebrates constitute about 90 percent of all the known animals. The invertebrates are usually categorized into as lower and higher invertebrates based on their organization and evolutionary position. The lower invertebrates are the higher invertebrates are simple in body organization generally larger in size and and generally smaller in size. possess a complex body The lower invertebrates include organization. various phyla such as The higher invertebrates Protozoa, Porifera, include various phyla such as, Coelenterata, Annelida, Arthropoda, Platyhelminthes and Mollusca and Nematoda. Echinodermata.  PROTOZOA KINGDOM: PROTISTA  KINGDOM PROTISTA Inhabit aquatic areas and terrestrial areas. Protists are classified into 12 Phyla which can be placed into 3 main groups plant-like 5  PROTOZOA ▪Unicellular, heterotrophic, eukaryotic organisms. ▪Protozoan means “first animal”. ▪20,000 species, only a few are pathogens. ▪Most are free-living organisms that inhabit water and soil. Some live in association with other organisms as parasites or symbiosis. ▪Reproduce asexually by fission, budding, or schizogony. ▪Some exhibit sexual reproduction (e.g.: Paramecium). ▪Trophozoite: is a vegetative stage. ▪Cyst: Some protozoa produce a protective capsule under adverse conditions (toxins, scarce water, food, or oxygen).  Types of movement Classified by the 3 ways they move: 1) Cilia - tiny beating hair-like structures Coordinated movement between individual cilia 2) Flagellum - whip-like tail(s) Back and forth wave motion 7 3) Pseudopodia - projection of cytoplasm that sticks out like a foot (“false foot”) Sessile - movement No locomotion (_________)  Nutrition Most are heterotrophic aerobes. Parasitic intestinal protozoa can grow anaerobically. Some ingest whole algae, yeast, bacteria, or smaller protozoans. Others live on dead and decaying matter. Parasitic protozoa break down and absorb nutrients from their hosts. Digestion takes place in vacuoles. Waste may be eliminated through plasma membrane or an anal pore. Reproduction All Protozoa can reproduce asexually One “parent” for reproduction Called binary fission During binary fission, one protozoan cell divides into two identical individuals. 10 Classification of Protozoa 1- Phylum :Sarcomastigophora Move using pseudopods (false feet) or flagella. A. Subphylum: Sarcodina a- Move by extending blunt, lobe like projections (pseudopods). b- Amoebas engulf food like bacteria and other protozoans with pseudopods and phagocytize it. c- Several species cause amoebic dysenteries of varying degrees of severity. Entamoeba histolytica: Feeds on red blood cells. Produces dysentery and extraintestinal cysts.  Amoeba ▪ Just visible to the naked eye. ▪ Unicellular. ▪ Moves by pseudopodia which give appearance of cell changing size and shape. ▪ Aquatic - lives in ponds, ditches or slowly moving streams. 12  Feeding sequence. psuedopodia surround and engulf food particle. process called phagocytosis 13  B. Subphylum :Mastigophora 1-Move by one or more flagella. Some parasitic flagellates have up to eight flagella. 2-Most are spindle shaped with flagella projecting from anterior end. 3-Outer membrane is a tough pellicle. 4- Food is ingested through an oral groove. Important pathogens: Trichomonas vaginalis: Causes genital and urinary infections. Transmitted sexually or by fomites. Giardia lamblia: Causes a persistent intestinal infection (giardiasis) with diarrhea, nausea. Trypanosoma brucei gambiense: Hemoflagellate (blood parasite). Causes African sleeping sickness.  2. Phylum: Apicomplexa (Sporozoa) Important pathogens: Plasmodium vivax and falciparum: Cause malaria in humans (intermediate host). Major cause of worldwide mortality: Kill 3 million people/year and infect 500 million. Transmitted by Anopheles mosquito (definitive host). DDT was used extensively in 1960s in an attempt to eradicate the mosquito vector. Successful vaccine not available yet. Life Cycle of Plasmodium spp. the Infectious Agent of Malaria  3- Phylum: Ciliophora a- Move and obtain food using cilia. b- Only known human pathogen is Balantidium coli, which causes a severe intestinal infection in pigs and humans. Paramecium Unicellular, slipper-shaped paramecium-500 Move by coordinated beating of many cilia. Aquatic - mostly found in ponds and streams. Usually do not cause diseases in humans 20  Paramecium feeding occurs in the funnel-shaped gullet (buccal cavity) where food is drawn in by external and internal cilia to form food vacuole. Ingests organic detritus and other small organisms like bacteria and other protozoans 21 Paramecium Food to waste pathway 22 Reproduction in Paramecium 1-Conjugation (sexual) Form structure called conjugation tube to exchange genetic material 2- Binary fission (asexual) N = nucleus F= Fission plane 23