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Section 19.1 Summary – pages 503-509. What is a protist?. Kingdom Protista contains the most diverse organisms of all the kingdoms. Protists may be unicellular or multicellular, microscopic or very large, and heterotrophic or autotrophic. All protists are eukaryotic.
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Section 19.1 Summary – pages 503-509 What is a protist? • Kingdom Protista contains the most diverse organisms of all the kingdoms. • Protists may be unicellular or multicellular, microscopic or very large, and heterotrophic or autotrophic. • All protists are eukaryotic.
Section 17.2 Summary – pages 450-459 A Paramecium Protists: A diverse group Anal pore Cilia • Protozoa are unicellular, animal-like heterotrophs. • They usually reproduce asexually, but some also reproduce sexually. Oral groove Gullet Contractile vacuole Micronucleus and macronucleus
Section 19.1 Summary – pages 503-509 What is a protist? • Other protists are plantlike autotrophs, using photosynthesis to make their food. • Plantlike protists are called algae Algae
Section 19.1 Summary – pages 503-509 What is a protist? • Other protists are more like fungi because they decompose dead organisms. • Slime molds and water molds are decomposers. Slime mold
Section 19.1 Summary – pages 503-509 What is a protist? • Some protists cause diseases, such as malaria and sleeping sickness, that result in millions of human deaths throughout the world every year. • Unicellular algae produce much of the oxygen in Earth’s atmosphere and are the basis of aquatic food chains.
Section 19.1 Summary – pages 503-509 Diversity of Protozoans • There are four main groups of protozoans: the amoebas, the flagellates, the ciliates, and the sporozoans.
Section 19.1 Summary – pages 503-509 Amoebas: Shapeless protists • Amoebas form pseudopodia to move and feed. Pseudopodia Cytoplasm Nucleus Food vacuole Contractile vacuole
Section 19.1 Summary – pages 503-509 Flagellates: Protozoans with flagella • Protists which have one or more flagella are called flagellates. • Flagellated protists, such as Euglena, move by whipping their flagella from side to side. Nucleus Chloroplast Mitochondrion Eyespot Flagellum Pellicle Contractile vacuole
Section 19.1 Summary – pages 503-509 Ciliates: Protozoans with cilia Anal pore Cilia • Protists that use cilia to move are called ciliates. Oral groove • Ciliates live in every kind of aquatic habitat—from ponds and streams to oceans and sulfur springs. Gullet Contractile vacuole Micronucleus and macronucleus
Section 19.1 Summary – pages 503-509 Sporozoans: Parasitic protozoans • All sporozoans are parasites. • They live as internal parasites in one or more hosts and have complex life cycles. • Plasmodium are organisms that cause the disease malaria.
Section 19.1 Summary – pages 503-509 Sporozoans and malaria • The life cycle of Plasmodium involves two hosts—mosquitoes and humans.
Section 19.1 Summary – pages 503-509 Sporozoans and malaria Gut wall of mosquito Zygote Gametes Mosquito bites a new, uninfected person Mosquito feeds on infected person Sporozoites Human host