Chapter 28 - Protists Flashcards
Protist -
eukaryotes that are not plants, animals, or fungi.
Protists are __________
Unicellular
Contractile vacuoles -
pump excess water from the protistan cell
Ocelloid -
eye-like organelle with components resembling the lens and retina in the eyes of vertebrates and some other animals
Mixotrophs -
combine photosynthesis and heterotrophic nutrition
Gram-negative bacteria -
have two cell membranes, an inner plasma membrane and an outer membrane that is part of the cell wall
Secondary endosymbiosis -
organism is ingested in the food vacuoles of heterotrophic eukaryotes and becomes an endosymbiont itself
Excavata (the excavates) -
one of the four main groups of protists: a clade that was originally proposed based on morphological studies of the cytoskeleton, members of this diverse group have an “excavated” feeding groove on one side of the cell body.
Diplomonads -
one of the four main groups of protists: have reduced mitochondria called mitosomes so they get the energy they need from anaerobic biochemical pathways. Many are parasites
Mitosomes -
organelles lack functional electron transport chains and hence cannot use oxygen to help extract energy from carbohydrates and other organic molecules
Parabasalids -
one of the four main groups of protists: also have reduced mitochondria; called hydrogenosomes
Hydrogenosomes -
these organelles generate some energy anaerobically, releasing hydrogen gas as a by-product
Euglenozoans -
one of the four main groups of protists: a diverse clade that includes predatory heterotrophs, photosynthetic autotrophs, mixotrophs, and parasites. The main morphological feature that distinguishes protists in this clade is the presence of a rod with either a spiral or a crystalline structure inside each of their flagella
kinetoplastids -
have a single, large mitochondrion that contains an organized mass of DNA called a kinetoplast. These protists include species that feed on prokaryotes in freshwater, marine, and moist terrestrial ecosystems, as well as species that parasitize animals, plants, and other protists
“bait-and-switch” defense -
the urface of a trypanosome is coated with millions of copies of a single protein. However, before the host’s immune system can recognize the protein and mount an attack, new generations of the parasite switch to another surface protein with a different molecular structure
A euglenid -
has a pocket at one end of the cell from which one or two flagella emerge
SAR
supergroup, also just SAR or Harosa, is a clade of eukaryotic organisms that includes stramenopiles, alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades
The stramenopiles -
one major subgroup of SAR that includes some of the most important photosynthetic organisms on the planet and is grouped due to their flagellums
In most stramenopiles, this “______” flagellum is paired with a shorter “_______” (nonhairy) flagellum
hairy; smooth
The three groups of stramenopiles:
diatoms, oomycetes, and brown algae
Diatoms -
unicellular algae that have a unique glass-like wall made of silicon dioxide embedded in an organic matrix
estimated ________ living species, _______ are a highly diverse group of protists
100,000; diatoms
Brown algae -
the largest and most complex algae, all are multicellular, and most are marine. Especially common along temperate coasts that have cold-water currents. They owe their characteristic brown or olive color to the carotenoids in their plastids
Holdfast -
a rootlike specialized structure which anchors the alga