Paramecium
A paramecium is a unicellular organism belonging to the protozoa type. It has a characteristic shape resembling the sole of a shoe, hence the name. It feeds on bacteria and small organic particles, which are captured by the oral groove and digested in food vacuoles. Paramecia reproduce asexually (by transverse division) and sexually (by conjugation). They inhabit freshwater environments such as ponds, lakes, and rivers, where they play an important role in food chains and ecosystems.
Did you know that...
01
50 micrometers per second
The speed of a paramecium is 50 micrometers per second.
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300-400 cilia
A paramecium has 300-400 cilia per cell.
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200 days
A paramecium lives on average for 200 days.
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Up to 1000 bacteria
It can ingest up to 1000 bacteria per hour.
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60 species
60 different species of paramecia are known to science.
Structure and functions of microorganisms
Large Nucleus (Macronucleus)
A physiologically active nucleus, involved in almost all life processes of ciliates. It is responsible for nutrition, respiration, movement, and metabolism. Typically very rich in DNA, it is large (up to 1-2 mm in length) and often has a complex shape. It divides by constriction, and sometimes buds.
Small Nucleus (Micronucleus)
A generative nucleus, smaller of the two nuclei in a ciliate (Ciliophora) cell, which contains DNA in an inactive form and is necessary for the exchange of genetic information during the sexual process. Some ciliates have several (up to 100) micronuclei. The micronucleus is diploid and divides by mitosis without disrupting the nuclear envelope.
Mouth (Cytostome)
The site for the ingestion of food particles: detritus, bacteria, unicellular algae. Sometimes the cell mouth is located in a depression — the peristome. The cell mouth leads to the cell pharynx — a cylinder made of microtubules that goes deep into the cell.
Pharynx
An intracellular formation that is a depression in the membrane and cytoplasm. Cilia around the mouth drive water containing bacteria into it.
Cytoproct (Poroshitsa)
A special opening in the outer dense layer of cytoplasm (pellicle) of a ciliate, through which undigested food residues are expelled. The cytoproct is located on the ventral side of the cell between the cell mouth (cytostome), which in some ciliates is located in the area of the oral cavity (peristome), and the rear end of the body.
Contractile Vacuole
Regulates osmotic pressure in freshwater ciliates and consists of a central reservoir and 5-7 radial canals. Due to a higher concentration of dissolved substances inside the ciliate compared to the surrounding water, water enters, filling the canals, which then empty into the vacuole, turning it into a bubble. The water is then expelled through a special duct, and the process repeats. Marine species do not have contractile vacuoles.
Digestive Vacuole
Moves around the cell with the cytoplasm. Food is digested within these vacuoles, and the resulting substances are released into the cytoplasm.
Pellicle
The membrane of single-celled primitive organisms, which has a very dense structure that allows them to maintain their shape and also protects against the negative impact of the environment.
Cilia
These are thin, numerous protrusions on the cell surface that aid in movement, as they can perform rhythmic contractile movements. Through their sequential contraction—they alternately tense and relax—the ciliate appears to swim, propelled by many small, short "hands."
