Coral reefs are among the world's richest ecosystems, second only to tropical rain forests. like the tropical rainforest, the coral reef ecosystem is in danger. coral is being harmed by all but one of the following.

D) Scientists are actually trying to build up certain minerals, like white carbonate, by using underwater electrical currents. Coral are very sensitive to changes in the environment, so any change in temperature, salinity, or sediments will harm the reefs. Blast fishing does not just kill fish; it destroys the entire area.

his research revealed two genetically different groups of prokaryotes, which justified splitting kingdom monera into two kingdoms. the genetic and cellular differences were so great, that these two kingdoms were eventually placed into different domains in the current three-domain system.

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".