Protozoa - Lífverur og Bygging

Protozoa

• Protozoa are single-celled eukaryotic organisms.
• They are classified under the kingdom Protista.
• They are a diverse group with various feeding and locomotion methods.
• Protozoa include ciliates, amoebae, flagellates, and sporozoans.
• They are found in diverse environments, such as freshwater, saltwater, soil, and even inside other organisms.
• Many protozoa are important in various ecological roles, including decomposition and nutrient cycling.
• Some are important parasites of humans and other animals and play a role in disease.

Protozoa - Structure

• Protozoa have a nucleus enclosed within a membrane.
• They have various organelles, which include golgi apparatus, lysosomes, mitochondria, endoplasmic reticulum, and vacuoles.
• Structurally, protozoa have diverse configurations, often with mouth-like structures for feeding and appendages for movement.
• Different groups of protozoa may have different structures.

Protozoa - Locomotion

• Protozoa utilize varied methods for movement, including flagella, cilia, and pseudopodia ("false feet").
• These methods allow them to move through their environment.

Protozoa - Feeding

• Protozoa have different mechanisms for obtaining nutrients, depending on the species.
• Some feed on other organisms, while others consume organic matter or dissolved nutrients from the surroundings.

Protozoa - Reproduction

• Protozoa reproduce asexually through binary fission, where one cell splits into two.
• Some reproduce sexually through conjugation, exchanging genetic material between cells.
• More complex modes of reproduction exist depending on species.

Phylum Kinetoplastida - flagellates

• This group includes over 600 species.
• Many species are parasitic.
• A defining feature is the kinetoplast- a specialized organelle containing DNA, located within a mitochondrion.
• Some species cause sleeping sickness (Human African trypanosomiasis).

Phylum Apicomplexa - sporozoans

• This phylum includes over 5,000 species.
• They are parasites of animals, including humans.
• Species are characterized by a unique apical complex at one end of the cell, used to penetrate host cells
• A major example is Plasmodium which causes malaria.

Phylum Ciliata - ciliates

• This phylum has over 8,000 species, most of which are free-living.
• Cilia are used for movement and feeding.
• A distinctive feature is the presence of two types of nuclei: a macronucleus that controls daily functions and a micronucleus involved in reproduction.

Phylum Dinoflagellata - dinoflagellates

• Over 4,000 species are located primarily in marine and freshwater environments.
• Most are photosynthetic; some are heterotrophic.
• Two flagella are used for movement and rotation, aiding in locomotion, feeding, and water currents.
• Some species cause harmful algal blooms.

Phylum Granuloreticulosa - foraminiferans, radiolarians

• This phylum includes foraminiferans (forams) and radiolarians.
• Foraminifera are commonly found in marine environments and frequently have hard shells composed of calcium carbonate.
• Foraminifera are commonly used as indicators of past environments or marine geological time.
• Radiolarians have hard glassy shells, predominantly used in studies of marine sediment and paleontology.

Phylum Amoebozoa - amoebae

• Amoebae are characterized by their movement using pseudopodia.
• Most are single-celled, free-living organisms.
• Some species are parasitic, causing diseases in animals and humans.
• Amoebae are found in various aquatic and terrestrial habitats.

Phylum Choanoflagellata - collar flagellates

• About 150 species are known.
• They exhibit a collar-like structure around the base of the flagellum.
• They are closely related to animals (e.g. sponges).