What is a Paramecium?
Our friend Paramecium, coming from the Protista kingdom, is a unicellular ciliate protozoa. This organism is large enough to see without a microscope, each individual being approximately 120 micrometers. It is capable of reproducing both sexually and asexually, capturing prey and digesting food. It typically lives in marine environments such as the world’s freshwaters, ponds, lakes, and even inside of organisms such as humans, in which they act as parasites. Paramecia (plural of Paramecium) have hair like structures on their outer membranes which allow them to move/swim in all directions. These hair-like structures are called cilia. Click below to see the labelings! |
Thepellicle is the outer membrane of the cell which protects it and supports the cilia. Paramecia act as heterotrophs, meaning that they feed on other organisms to get their nutrition. They mostly feed on microorganisms such as algae, bacteria, euglena, water fleas, amoebas and most decaying matter. They get hold of their prey by using their cilia to sweep the food to the oral groove which consists of more cilia and into the cell mouth. Created by gullets, there arefood vacuoles inside the cell that store food. There are also contractile vacuoles that contract and force any excess water out of the cell. Anal pores are useful features in the cell which allow it to get rid of any waste. Furthermore, there are two types of nuclei: the macronucleus and the micronucleus. The micronucleus is in charge of cell division. The macronucleus is in charge of all the cell’s general functions. Paramecia create strong symbiotic relationships with green algae. This microorganism floats inside the cytoplasm of its host cell, the Paramecium, and provides food for the cell by undergoing photosynthesis. Paramecia are also great contributors of the carbon cycle, due to their consumption of bacteria that hover over decaying matter. In addition to eating the bacteria, Paramecia will moreover eat the decaying plant matter that they cover. This makes decomposition a faster and more efficient process. |
Duhn duhn duh.h . . . Didinium
Figure 3: Didinium sp feeding on its prey
Didinium are famous for generating strong relationships with Paramecium,
their main source of nutrition. These ravenous cells are also heterotrophic and
unicellular ciliate protozoa. Paramecium may appear larger, but Didinium use their techniques as predators to catch these creepy crawlies and to munch them all up. This is why Paramecium evolved to have cilia as their main propellers and feet to make 360o turns and to escape danger. Didinium have higher chances of breaking the escape by shootings their poisonous contents (or trichocysts) at the escaping cell in order to keep hold of it. Paramecia also have the advantage of using their trichocysts to catch their prey too, but never to fight back the Didinium.
their main source of nutrition. These ravenous cells are also heterotrophic and
unicellular ciliate protozoa. Paramecium may appear larger, but Didinium use their techniques as predators to catch these creepy crawlies and to munch them all up. This is why Paramecium evolved to have cilia as their main propellers and feet to make 360o turns and to escape danger. Didinium have higher chances of breaking the escape by shootings their poisonous contents (or trichocysts) at the escaping cell in order to keep hold of it. Paramecia also have the advantage of using their trichocysts to catch their prey too, but never to fight back the Didinium.
Reproduction
Paramecia reproduce both sexually and asexually. When they undergo asexual reproduction, or binary fission in other words, the macronucleus of the cell elongates, then splits in two. Once this has happened, the cell will pinch along the center and split, sharing half of its nucleus and organelles with each daughter cell. Paramecia are capable of reproducing asexually two to three times a day. When their surroundings become rough and uncomfortable, they immediately show signs of sexual reproduction, or conjugation. Steps of conjugation: 1. Parent cells align beside each other 2. With the process of meiosis, the micronucleus of each parent cell fuse together and divide to create four haploid nuclei. 3. Only one of the three haploid nuclei survives, and that nucleus divides mitotically to create two separate nuclei. 4. Once this has been done, the cells exchange genetic information and split. |
Adaptations Paramecia have existed for so long that the oldest fossil of a Paramecium organism was discovered in an old precious stone dating over 65 million years ago, during the Cretaceous period (when dinosaurs roamed the earth). The existence of the species in general would date back to approximately 200 million years ago. Considering that these organisms are unicellular, they haven’t evolved from any other organisms. They arose from simple prokaryotic bodies which were the basic building blocks of all eukaryotic species that ever existed. |