The three major types of symbiosis are mutualism, where both species benefit, commensalism, where one species benefits and the other is unaffected, and parasitism, where one species benefits and the other is harmed. Symbiotic relationships can occur within an organism's body or outside of it.
Examples of mutualism include the relationship between single-celled organisms or animals that incorporate algae into their bodies. They give the algae necessary nutrients, and in return receive chemical energy from the photosynthetic algae. Animals that have this sort of relationship include some sponges, sea anemones and clams.
Examples of commensalism include remora fish attaching to the bodies of sharks and eating scraps of food that escape their jaws, and barnacles living on the jaws of whales with a similar feeding strategy. Plants have commensal relationships as well, such as many orchids that grow on taller plants and benefit from the additional sunlight they obtain, without actually stealing nutrients from the host plant.
Parasitic relationships are many, and parasites include all disease-causing organisms. This category also includes insects such as fleas that suck the blood of hosts externally. Parasitism is a very efficient strategy for organisms, and parasites often lose many of the features of non-parasitic life forms, instead relying on their hosts for many of the functions of life.Learn More
The three types of fungi are yeast, mushroom and mold. Yeast is a unicellular fungus that can cause ringworm and baker’s yeast, mushroom is a fungus that grows from soil or trees and mold is a multicellular fungus that includes mildew.Full Answer >
The three types of natural selection are directional selection, disruptive selection and stabilizing selection. Natural selection is when organisms adapt to the environment and pass down these adaptations to their offspring when they breed. Those that are not able to adapt die before breeding, putting an end to unfavorable traits.Full Answer >
Fungi, bacteria and viruses form the three categories of microorganisms. These microorganisms, or microbes, live in all areas of the world and perform diverse duties. Some help living organisms while others act as pathogens; they come in uni-cellular or multi-cellular forms, but their small sizes make microorganisms only visible to humans through microscopic lenses.Full Answer >
According to Spark Notes, eubacteria comprise an ancient group and can be saprophytes, photoautotrophs or symbionts. Eubacteria are also known as the true bacteria. They are able to reproduce by binary fission, with a split approximately every 20 minutes.Full Answer >