CHAPTER 21 Flashcards
Six supergroups
Archaeplastids Chromalveolates Excavates Amoebozoa Rhizaria Opisthokonts
Protists
Domain Eukarya
Kingdom Protista
Unicellular
Photosynthetic/Heterotrophic
Endocytosis
Ingest particulate food matter pulling them into food vacuoles lysosomes fuse and introduce enzymes
Parasitic
Typically absorb body fluids of host
Mixotrophic
Combine autotrophic and heterotrophic nutritional modes
Lifecycles
Many protists survive unfavorable environments by forming cysts
Asexual reproduction most common
Some species have an unusual my mitosis
Sexual Reproduction
Meiosis
Allows frequent genetic recombination
Mitosis
Parent cells split to form equal size daughter cells
Schizogony
Cell division preceded by several nuclear divisions one parent cell produces several individuals
Meiosis
Union of haploid gametes to form a diploid cell.
Evolution and diversity of protist
Protist are not plants animals or fungi
They are not monophyletic
Chromalveolata ( alveolates)
Alveolates have alveoli lying beneath their plasma membrane
includes diniflagellates ciliates and apicomplexans
Dinoflagellates
Typically two flagella
Symbiotic zooxanthellae are found in corals
Karenia brevis causes red tide.
Some lack chloroplast and considered parasitic instead of mutualistic
Ciliates
Pellicle- tough flexible outer covering
Have to types of nuclei
Micronucleus
Macronucleus
Have two types of vacuoles
Food vacuoles
contractile vacuoles
Apicomplexans
Spore forming animal parasites
Apical complex a unique arrangement of organelles
Enables protist to invade its host cell
(Ex.) Malaria
Plasmodium
Hosts are anopheles(mosquito) and the human
Toxoplasma Gondii
Invades the epithelial cells of the human intestine
Causes Taxoplasmosis
Primary host is Falidae(cat)
Escavata
Absent mitochondria and distinctive flagella
Includes euglenids,parabasalids, diplomonads, and kinetoplastids
Euglenids
Small freshwater unicellular organisms
Two flagella and one eyespot with a photo receptor
One flagellum is much longer than the other
Sell bounded by flexible pellicle
Chloroplast surrounded by three rather than two membranes
Many are mixotrophs
Parabasalids
Single nuclei flagellated Endosymbionts of animals Able to survive in low oxygen environments Lack mitochondria Causes trichomonas vaginalis
Diplomonads
Two nuclei Two sets of flagella endosymbionts of animals Lack mitochondria Causes giardia ( Look at Giardia)
Kinetoplastids
Predominately parasitic
Unique single mitochondria
Causes Chagas disease and African sleeping sickness( Look at cycles)
Amoebozoa
Protozoans that move by pseudopods
Usually live in aquatic environments where they are often part of the plankton
Pseudopods form when cytoplasm streams forward in a particular direction
Uses Phagocytosis for food ingestion
Entamoeba Histolytica
A parasite of the human: causes amoebic dysentery can be fatal
Amoeba Proteus
The cytoplasm region is divided into two parts outer layer membrane ectoplasm and Inner watery mass endoplasm
Found in freshwater
Produce sexually
eat other protozoans
Rhizarians
Radiolarians and for Foraminiferans
Outer skeleton called a test
Radiolarians: Glassy skeleton made of silica Needle like pseudopods Float in marine habitat Heterotrophic
Foraminifera:
Heterotrophic marine protist
Calcium carbonate test is often multi chambered
Opisthokonts
Choanoflagellates- animal like protozoans that are near relatives of sponges
Unicellular
Asexual reproduction
Single flagellum surrounded by funnel shaped collar
Filter feeders
Phagocytosis is used
