What is coral bleaching and how might corals be able to adapt to avoid the destruction of coral reefs?
What will be an ideal response?
Answer: Coral bleaching occurs when the phototrophic symbiont in the coral dies, revealing the underlying colorless (white) limestone skeleton of the coral. It is thought that the main factors in coral bleaching are an increase in both water temperature and high UV irradiance. Global climate change is increasing the sea surface temperature. The phototrophs are very sensitive to changes in temperature and UV irradiance, which may cause an increase in reactive oxygen species that causes the coral to rapidly kill and expel the unhealthy photobionts. Corals and their symbionts, may, however be able to adapt to increased temperatures. There are over 150 different phylotypes of the dinoflagellate symbiont Symbiodinium, many of which may have different heat and UV stress tolerance. Corals are capable of either switching symbionts through horizontal transmission or swapping symbionts by allowing a rare symbiont to take over the population. Understanding which symbionts are capable of colonizing hosts that have lost their initial symbionts can have predictive value for the future of reef ecosystems.
You might also like to view...
The presence of both thin-lipped and thick-lipped cichlid fish in Lake Apoyeque, Nicaragua, is a well-known example of _______.
a. allopatric speciation b. adaptive radiation c. sympatric speciation d. allopatric radiation
Which of the following activities is likely to deplete an aquifer fastest?
A) desert trees B) deep-well drilling for farms C) using chlorofluorocarbons D) employing molybdenum-based fertilizers
A book is being publicized that purports to provide proof that aliens from another planet brought life to Earth. The proof they show are strange fossils of multicellular organisms that look like no animal you have ever seen
What group actually includes these "aliens"? A) organisms with adaptive radiation B) the Ediacaran fauna C) ancient archaea D) endosymbiotic organisms
Which type of junction contributes the most to the polarization of epithelial cells?
(a) adherens junctions (b) desmosomes (c) tight junctions (d) gap junctions