Presentation on theme: "Kingdom Protista n All members of this Kingdom, are unicellular or very simple multicellular organisms. n Members of this kingdom have been around for."— Presentation transcript:
Kingdom Protista n All members of this Kingdom, are unicellular or very simple multicellular organisms. n Members of this kingdom have been around for about 1.5 billion years.
Categories of Kingdom Protista n There are two major categories; the protozoa (animal- like) and the protophyta (plant- like)
General Characteristics of the Protozoa n 1. One -celled n 2. Eukaryotic n 3. Shape determined by the cell membrane or a thicker, elastic membrane called the pellicle. n 4. Reproduce asexually and sexually. n 5. Aquatic
General Characteristics of the Protozoa continued n 6. Heterotrophic n 7. Many are motile-use cilia, flagella or pseudopodia. n 8. Important role in food chain and in the decay process. n 9. Dormant protozoa are called cysts. n 10. Two famous protozoa are the paramecium and the amoeba.
General Characteristics of the Protophyta n 1. One -celled, filaments and colonies. n 2. Eukaryotic n 3. Shape determined by cell wall. n 4. Reproduce asexually and sexually. n 5. Aquatic n 6. Phototrophic n 7. Motile by cilia or drift in water.
General Characteristics of the Protophyta continued. n 8. Known for their role in the food chain and for their contribution to the Earth’s oxygen supply. n 9. Dormant cells are called spores. n 10. Two of the most famous protophyta are the Euglena and diatoms.
The Ameba n The common amoeba, Amoeba proteus, belongs to the phylum known as Sarcodina. n It lives in fresh water. n It is an independent cell, with a nucleus and cytoplasm. n It has no permanent organelles.
The Ameba continued n Although the amoeba has a simple structure, it can move, reproduce,capture and ingest food, digest food, egest wastes, respire and respond to stimuli.
The Amoeba-Movement n Movement known as amoeboid movement. n Uses pseudopods, formed by the plasmasol and plasmagel that comprise the cytoplasm of the amoeba.
Foraminiferans n This is another group of sarcodinians. n Abundant in the oceans. n They too move by way of pseudopods. n They are surrounded by shells made up of calcium. n Eventually the remains of the shells may form chalk deposits.
The Paramecium n One of the most complex protozoa. n Unicellular n Prefers stagnant water. n Has a definite shape(unlike the amoeba). n Certain parts of the cytoplasm do certain things.
Cilia n Paramecia move by way of cilia and hence are members of phylum Ciliophora n Note the hair-like cilia on this ciliate.
Water Control in the Paramecium
Formation and Processing of Food Vacuoles n Food is swept by cilia into the cell mouth. n Food passes into the gullet and a food vacuole forms at it’s base. n Enzymes from the cytoplasm enter the vacuole to digest food. n Wastes from the vacuole are expelled through the anal pore.
Locomotion n Ciliates travel along a spiral path, with the cell rotating around it’s long axis. n A sine wave pattern forms.
The Protophyta n There are about eleven thousand species of algal protists. n They are spread over three phyla;Euglenophyta, Chrysophyta, and Pyrrophyta.
Phylum Euglenophyta n Most are unicellular, but a few are colonial. n Animal and plant-like characteristics. n Use photosynthesis to produce paramylum. n In absence of light they are heterotrophic. n Use flagella for locomotion.
Phylum Euglenophyta cont. n A contractile vacuole is present that serves to remove excess water. n The presence of a light sensitive eyespot or stigma, allows the Euglena to locate
Phylum Pyrrophyta - The Dinoflagellates n Unicellular algae. n Photosynthetic and heterotrophic. n Tough outer shell. n All have two flagella. n Reproduction is asexual. n Food stored as oil or starch.
Red Tide n From time to time,there are algal blooms and the so-called red tides form. n Toxins from the dinoflagellates are released. n Fish die from the toxin and paralytic shellfish poisoning(PSP) may occur.
Phylum Sporozoa n Members of this phylum are non-motile protozoa. n An excellent example of a sporozoan is Plasmodium vivax, the causative agent of malaria. n There are two stages involved in the life cycle of Plasmodium vivax ; Asexual (in the human) and Sexual (in the mosquito).
Phylum Sporozoa con’t. n When an infected mosquito bites a human, spores enter the bloodstream and produce gametes in the red blood cells. n When an infected human is bitten by a mosquito, gametes unite in the gut of the mosquito to form a zygote. n In the mosquito, the zygote matures into more spores which are passed on to the next human victim.
Interesting Facts About Malaria n In the days of British colonization of India, soldiers contracted malaria. n The treatment was to give the soldiers quinine mixed with water (tonic water), mixed with gin (to kill the taste). n This gave rise to a popular drink amongst the soldiers known as “Gin and Tonic”.
More Interesting Facts About Malaria n War veterans who caught malaria overseas, have had recurring episodes of this disease. n In fact, this has been observed in patients in nursing homes right here in Kings County.
The Trypanosome n Member of Phylum Mastigophora. n It is a zooflagellate. n Causative agent of African Sleeping Sickness. n Transmitted from infected wild animals by the tsetse fly to humans
Trypanosome continued n Victim develops a fever and becomes weak and anemic. n This is due to the effect of the toxic metabolites produced by this organism.
Trypanosome continued n Finally the parasites invade the fluid surrounding the brain and spinal cord, the person loses consciousness and dies. n Drugs are effective in the early stages of this disease.