Malaria is caused by a parasite called Plasmodium, which is  transmitted via the bites of infected mosquitoes. In the human  body, the parasites multiply in the liver, and t â¦ hen infect red  blood cells. Usually, people get malaria by being bitten by an  infective female Anopheles mosquito.   *Ninety percent of malaria-related deaths occur in Africa. Malaria is commonly associated with poverty, but is also a cause of poverty.   *Malaria is one of the most common infectious diseases and an enormous public health problem.
metamorphic rock. (petrology). A rock formed from preexisting solid rocks by mineralogical, structural, and chemical changes, in response to extreme changes in temperature, pressure, and shearing stress.
Metamorphic rocks arise from the transformation of existing rock types, in a process called metamorphism, which means change in form. The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 Â°C) and pressure (150 megapascals (1,500 bar)), causing profound physical and/or chemical change. The protolith may be a sedimentary, an igneous, or even an existing type of metamorphic rock. Metamorphic rocks make up a large part of the Earth's crust and form 12% of the Earth's current land surface. They are classified by texture and by chemical and mineral assemblage (metamorphic facies).