Current thinking on how the Toxoplasma gondii parasite invades its host is incorrect, according to a study published today in Nature Methods describing a new technique to knock out genes. The findings could have implications ...
Definition. Coral bleaching is a process whereby the coral colonies lose their colour, either due to the loss of pigments by microscopic algae (zooxanthellae) living in symbiosis with their host organisms (polyps), or because these zooxanthellae have been expelled.
When corals are stressed by changes in conditions such as temperature, light, or nutrients, they expel the symbiotic algae living in their tissues, causing them to turn completely white. When a coral bleaches, it is not dead.