Protozoa Characteristics and Classification

Unicellular, eukaryotic organisms that lack a cell wall and are either free-living or parasitic. They are often found in aquatic environments, with some being aerobic and others anaerobic.

The active feeding and multiplying stage of parasitic protozoa.

A stage of some protozoa with a thick, protective membrane or wall. They are often resistant to harsh environments.

A type of protozoan that moves using flagella. An example is Trypanosoma.

A type of protozoan that moves using pseudopods. An example is Amoeba.

A type of protozoan that is non-motile and often has a complex life cycle. An example is Plasmodium.

A type of protozoan that moves using cilia. An example is Paramecium.

A diverse group of eukaryotic organisms that are photosynthetic. They are important primary producers in aquatic ecosystems.

A group of algae characterized by golden-brown pigments, unicellular structure, and a unique cell wall made of silica (glass). They reproduce mainly asexually through cell division.

A diverse group of algae with parietal chromatophores that show varied pigmentation, including shades of brown. They are motile with unequal flagella and often have coccoid advanced forms.

A class of algae known as dinoflagellates, characterized by their forward-spiraling swimming motion. They have a unique structure with two flagella, a nucleus with condensed chromosomes, and a cell covering known as a theca. They can cause harmful red tides.

A class of algae found in freshwater environments. They are characterized by their bright green chromatophores, with an excess of xanthophyll, and two almost equal flagella.

A class of algae found in freshwater environments, with a distinctive green pigmentation due to their chloroplasts. They are motile with one or two flagella and have a complex vacuolar system and a prominent nucleus.

A class of algae mainly found in marine environments, particularly on rocky shores in cold and temperate waters. They are known for their brown accessory pigment, fucoxanthin, and their large size, ranging from filamentous to bulky forms.

A group of organisms that do not share a common ancestor and are not related. They evolved independently.

Eukaryotic organisms, often found in aquatic environments, that photosynthesize.

Green algae are often aquatic, but can also live in diverse habitats like snow, tree trunks, and soils. They contain chlorophylls a and b, used for photosynthesis, and have cellulose cell walls. Reproduction can be sexual or asexual, with diverse forms.

Yellow-green algae typically live in freshwater, but some are marine. They have distinctive pigments, including yellow xanthophyll, and their cell walls are composed of pectic compounds. While sexual reproduction is rare, it occurs through isogamous forms.

Often found in fresh and marine waters, golden algae contain chlorophylls a and c, masked by the brown pigment fucoxanthin. They have unequal flagella and store food as laminarin or chrysolaminarin.

Diatoms are ubiquitous in marine and freshwater environments, serving as indicators of past ecological conditions. They have unique siliceous cell walls and are often used in research to study past climates.

A classification scheme for algae proposed by Fritsch in 1945. It divided algae into 11 classes, each with characteristic features.

The study of algae, a diverse group of photosynthetic organisms.

Red algae that mainly live in saltwater but can also be found in freshwater. They contain chlorophyll a but are masked by phycobilin pigments. These organisms are multicellular and lack flagella, with complex structures and reproduce sexually.

Blue-green algae that are common in both freshwater and saltwater environments. Their unique pigments, phycobilins, are bound to protein granules within phycobilisomes. They exhibit rudimentary structures, with no proper chromatophores and no motile stages. They reproduce asexually.

A diverse group of organisms that lack chlorophyll and obtain nutrition by absorbing it. They include yeasts, molds, and mushrooms, and exhibit complex life cycles with both asexual and sexual reproduction. They can be unicellular or multicellular and often have cell walls made of chitin.

Key criteria used to classify fungi, including the structure of their reproductive organs, the types of spores they produce, their reproduction methods (sexual or asexual), and their habitat (parasitic, saprophytic, or mutualistic).

A group of fungi that are primarily found in terrestrial environments, like soil and decaying matter. They produce thick-walled spores called zygospores. A common example is Rhizopus, commonly known as bread mold.

The largest group of fungi, known for producing spores in sac-like structures called asci. They encompass both unicellular yeast and multicellular fungi. Examples include Saccharomyces, Penicillium, and Aspergillus.

Known for producing spores on club-shaped structures called basidia. They include mushrooms, puffballs, and bracket fungi. Common examples include Agaricus, Amanita, and Coprinus.

Often referred to as imperfect fungi because their sexual reproductive stage is unknown. They are a diverse group with various ecological roles.