The jellyfish Clytia hemisphaerica

Red algae, also known as rhodophytes, are primarily found in marine environments, though some species inhabit freshwater and terrestrial ecosystems. These organisms exist in both unicellular and multicellular forms, with some multicellular varieties reaching macroscopic sizes.As phototrophic organisms, red algae contain chlorophyll a; however, their chloroplasts lack chlorophyll b. Instead, they possess phycobiliproteins, which serve as major light-harvesting pigments, similar to those found in...

The group Stramenopiles include some phototrophic microorganisms. Members of this group possess flagella covered in numerous short, hairlike extensions, a feature that inspired the group's name, derived from the Latin words for "straw" and "hair." Some of the main categories of Stramenopiles include diatoms, golden algae, and brown algae.Diatoms are unicellular, photosynthetic eukaryotes, with over 200 known genera. They play a key role in the planktonic communities of both marine and...

Alveolates are a group of organisms recognized by the presence of alveoli, which are cytoplasmic sacs located beneath the cell membrane. While their function remains uncertain, alveoli may help regulate water balance by controlling how much water enters and leaves the cell. In dinoflagellates, these structures may serve as armor plates. There are three major types of alveolates: ciliates, which move using cilia; dinoflagellates, which use flagella for movement; and apicomplexans, which are...

Cyanobacteria are a diverse group of oxygenic, phototrophic bacteria that played a pivotal role in converting Earth’s atmosphere from anoxic to oxygen-rich billions of years ago. They exhibit remarkable morphological diversity, ranging from unicellular forms to filamentous types, with cell sizes varying between 0.5 μm and 100 μm. Cyanobacteria are classified into five groups: Chroococcales (unicellular, dividing by binary fission), Pleurocapsales (unicellular, dividing by...

Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...

Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...