What are alveolates characterized by?
The alveolates are protists characterized by the presence of sacs of fluid under the cell membrane. These sacs, which are fluids enclosed by lipid fat or wax, are called alveoli, hence the name alveolates.
Which characteristic is unique to the alveolates?
The most notable shared characteristic is the presence of cortical (near the surface) alveoli (sacs). These are flattened vesicles (sacs) arranged as a layer just under the membrane and supporting it, typically contributing to a flexible pellicle (thin skin).
What makes stramenopiles unique?
The unifying feature of this group is the presence of a textured, or “hairy,” flagellum. Many stramenopiles also have an additional flagellum that lacks hair-like projections. Members of this subgroup range in size from single-celled diatoms to the massive and multicellular kelp.
What do all Alveolata have?
The alveolates include the dinoflagellates, about half of which are algae with complex plastids, and two large and important groups of protozoa: the apicomplexan parasites, and the mostly free-living ciliates (Figures 4(i)–4(m)).
Are alveolates unicellular or multicellular?
Alveolates are a recently recognized group of unicellular eukaryotes that unites disparate protists including apicomplexan parasites (which cause malaria and toxoplasmosis), dinoflagellate algae (which cause red tides and are symbionts in many corals), and ciliates (which are microscopic predators and common rumen …
Which feature best distinguishes protists from other eukaryotes?
Which feature best distinguishes protists from other eukaryotes? They cannot be categorized into a single kingdom. Tiny hairlike structures called —- are characteristic of certain protists. Some protists use a long whip-like structures called ____________ to swim.
Are alveolates heterotrophic?
Some of the most recognisable members of the alveolates are the ciliates, a group of heterotrophic protists that include Tetrahymena and Paramecium, and play important roles in microbial food webs. The majority of ciliates are free-living predators, although parasitism appears to have evolved several times 1, 7.
What characteristics do stramenopiles share?
Stramenopiles. Stramenopiles (also known as heterokonts) usually have a flagellate stage in the life cycle that has a characteristic type of stiff tubular ‘hairs’ arranged in two rows on one flagellum (see Patterson, 1999). These flagellates swim in the direction the hair-bearing flagellum is pointing.
How do the oomycetes differ from other stramenopiles?
The Oomycetes have individual mobile cells, however, with the characterisitics of the Stramenopiles (for instance, two flagella of different lengths, one with forked bristles). Their cell walls are built with cellulose instead of fungal chitin. Thus they are technically algae, not molds.
Are all alveolates unicellular?
An assemblage of unicellular eukaryotic organisms, sometimes placed in the phylum Alveolata, that are believed to have common ancestry based on certain morphological similarities and molecular systematics.
Are alveolates Heterotrophs?
How are protists different from other eukaryotes?
Some are tiny and unicellular, like an amoeba, and some are large and multicellular, like seaweed. However, multicellular protists do not have highly specialized tissues or organs. This simple cellular-level organization distinguishes protists from other eukaryotes, such as fungi, animals, and plants.
How are protists different?
Giant kelpForamsParamecium caudatumSea lettuceMarimoBrain‑eating amoeba
What is alveolates function?
These alveolates are photosynthetic, able to manufacture their own food from sunlight, carbon dioxide, and sufficient dissolved nutrients. The dinoflagellates are best known for their periodic population booms that result in “red tides” that may kill fish and shellfish.
Do stramenopiles have cell wall?
These organisms are naked (having no cell wall), 30- to 80-μm-long unicellular flagellates (Heywood, 1990); the anterior flagellum, responsible for the cell’s movements, bears mastigonemes, whereas the long, trailing flagellum is smooth.
What are the characteristics of oomycetes?
Oomycetes are characterized by cellulose containing coenocytic hyphae, biflagellate zoospores, and usually contain no chitin. Sexual reproduction can occur between gametangia (antheridia and oogonia) on the same or different hyphae.
What is the difference between oomycetes and fungi?
The key difference between oomycetes and true fungi is that oomycetes have cellulose, beta-glucans, and hydroxyproline in their cell wall while true fungi have chitin in their cell walls.
Are alveolates photosynthetic?
What are the characteristics of protists?
Protists have nuclear membranes around their DNA. They also have other membrane-bound organelles. Many protists live in aquatic habitats, and most are motile, or able to move. Protists have complex life cycles that may include both sexual and asexual reproduction.
How do protists differ from the organisms in all the other four kingdoms?
Protists are eukaryotes, which means their cells have a nucleus and other membrane-bound organelles. Most, but not all, protists are single-celled. Other than these features, they have very little in common. You can think about protists as all eukaryotic organisms that are neither animals, nor plants, nor fungi.