Amoebae, slime mold, algae and protactists are some examples of unicellular organisms. Unicellular organisms fall under the main groups of bacteria, archaea, protozoa, single-celled algae and single-celled fungi. The two general categories are prokaryotes, which lack membrane-bound nuclei and membrane-bound organelles, such as mitochondria; and eukaryotes, which are more complex, having membrane-bound organelles and nuclei.
Unicellular organisms are ubiquitous to most environments on Earth. Unicellular organisms have been found in the most extreme environments, such as arid deserts, frozen tundra, highly acidic subterranean environments and hydrothermal vents on the ocean floor; these organisms are called extremophiles. Extremophiles are described by the environments in which they grow optimally, such as acidophilic for acidic environments and thermophilic for environments with high temperatures.
Unicellular organisms can be innocuous to humans, but they are also responsible for diseases. Malaria is caused by a unicellular parasite of genus plasmodium. It is prevalent in tropical and sub-tropical environments. As of 2010, there were an estimated 219 million cases of malaria resulting in 660,000 deaths worldwide. The disease is transmitted from person to person by the bite of the Anopheles mosquito. Prevention includes the use of mosquito nets, pesticides and disruption of mosquito breeding grounds. There are several forms of treatment for malaria as well as ongoing development of a vaccine.Learn More
Multicellular organisms are composed of more than one cell, while unicellular organisms are a single living cell. This difference determines the size and complexity of an organism, as well as the division of labor within it. Each kind of organism has its own set of survival benefits.Full Answer >
Metabolic wastes, also known as excretes, are substances produced by the metabolic activities of living organisms. These substances cannot be used by the organism and are therefore excreted. These excretes include carbon dioxide, nitrogen compounds, sulfates, phosphates and water.Full Answer >
Organic foods are grown using traditional growing methods that promote environmental health and without chemical fertilizers, pesticides and industrial processing, and genetically modified organisms are plants or animals that have been modified using genetic engineering techniques to directly alter the organism's DNA. While GMOs can be grown using organic techniques, the genetic modification generally renders the plants ineligible for the organic label.Full Answer >
Archaebacteria include many unique characteristics and traits: they comprise one kingdom of living organisms, are among the oldest life forms on earth and prefer to live in the most extreme environments on the earth to name a few. Archeaebacteria are often grouped with eubacteria, although the two are quite distinct. Archaebatecteria predate eubacteria by millions of years and are more closely related to eukarya than actual bacteria.Full Answer >