List of Microscopic organisms
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A microorganism or microbe is an organism that is unicellular or lives in a colony of cellular organisms. The study of microorganisms is called ‘Microbiology’. Microorganisms live in all parts of the biosphere where there is liquid water, including soil, hot springs, on the ocean floor, high in the atmosphere and deep inside rocks within the Earth's crust. Most microorganisms are unicellular (single-celled), but this is not universal, since some multicellular organisms are microscopic, that are too small to be seen by the naked eye, while some organisms are macroscopic and visible to the naked eye. Microorganisms such as bacteria are almost all too small to be seen with the naked eye, though these are not qualified as animals. Eukaryotic (complex-celled) unicellular organisms with animal-like characteristics are called protists, but these too are not considered part of Kingdom Animalia (also known as metazoa). True animals are multicellular and have differentiated tissues. Microorganisms are critical to nutrient recycling in ecosystems as they act as decomposers.
What is the History of Microscopic animals?
Single-celled microorganisms were the first forms of life to develop on Earth, approximately 3–4 billion years ago. Anton van Leeuwenhoek, a Dutch tradesman and scientist, the Father of Microbiology, was one of the first people to observe microorganisms, using a microscope of his own design, some of which could magnify up to 500 times and made one of the most important contributions to biology. The smallest object that can be seen with the unaided human eye ranges from about 1/40 to 1 mm, but "microscopic" often refers to any animal smaller than 1 mm in width, especially smaller than 1/10 mm in width. Robert Hooke was the first to use a microscope to observe living things. Using a microscope, he did establish that there were forms of life that were not visible to the naked eye. Leeuwenhoek's discovery, along with subsequent observations by Lazzaro Spallanzani, an Italian Catholic priest, biologist and Louis Pasteur, a French chemist, ended the long-held belief that life spontaneously appeared from non-living substances during the process of spoilage. In 1876, Robert Koch established that microbes can cause disease. He found that the blood of cattle that were infected with anthrax always had large numbers of Bacillus anthracis, a bacteria. Koch found that he could transmit anthrax from one animal to another by taking a small sample of blood from the infected animal and injecting it into a healthy one, and this caused the healthy animal to become sick.
What are the different Microscopic animals?
- Micro-animals are animals that are microscopic and thus cannot be seen with the naked eye.
- Mostly these microorganisms are multicellular but none are vertebrates.
- Arthropods: Microscopic arthropods (an invertebrate animal having an external skeleton) include dust mites, and spider mites.
- Crustaceans: Microscopic crustaceans include copepods and the cladocera. Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles.
- Rotifers: Another common group of microscopic animals are the rotifers, which are filter feeders that are usually found in fresh water. The rotifers (commonly called wheel animals) make up a phylum of microscopic animals
- Some nematode species are microscopic, as well as many loricifera, including recently discovered anaerobic species, which spend their entire lives in an anoxic environment. The nematodes or roundworms (phylum Nematoda) are one of the most diverse of all animals.
- Although most microscopic animals are multicellular, myxozoa, jelly fish relatives from the phylum Cnidaria, are unicellular.
- Micro-animals reproduce both sexually and asexually and may reach new habitats as eggs that survive harsh environments that would kill the adult animal. However, some simple animals, such as rotifers and nematodes, can dry out completely and remain dormant for long periods of time.
What is the role played by Microscopic animals in our ecosystem?
microscopic animals are extremely important to the global ecosystem, making up a major portion of biomass and representing the base of some food webs.
- The smallest microscopic animals, like rotifers, mostly live on bacteria, while larger specimens consume smaller animals or suck fluids from trees.
- Mites are especially adapted to the latter, and are found on large numbers under the leaves of many plants.
- Dust mites, the most common cause of allergies, are found in nearly every human home on the planet, where they survive on dead skin cells that drop from human inhabitants. A common strategy for killing these tiny beasts is to reduce ambient moisture.
- Microorganisms are critical to nutrient recycling in ecosystems as they act as decomposers. As some microorganisms can fix nitrogen (Nitrogen fixation is the natural process, by which nitrogen in the atmosphere is converted into ammonia), they are a vital part of the nitrogen cycle, and recent studies indicate that airborne microbes may play a role in precipitation and weather.
- Since, microscopic animals are so numerous and distributed; only a portion of them have been described by science. Others will of course certainly be discovered in the near upcoming future, adding to our knowledge of the planet's biodiversity.
Do humans exploit Microscope animals?
are also exploited by people in biotechnology, both in traditional food and beverage preparation, and in modern technologies based on genetic engineering. However, pathogenic microbes are harmful, since they invade and grow within other organisms, causing diseases that kill people, other animals and plants.
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