The theory of endosymbiosis suggests that chloroplasts and mitochondria were once free-living prokaryotes, that were engulfed by larger prokaryotic cells. eventually, this relationship lead to the development of eukaryotic cells with cellular organelles. these organelles included mitochondria, and in some cases, chloroplasts. which of these is not supported by the endosymbiosis theory concerning organelles?

a) contain dna.
b) contain ribosomes.
c) are capable of living independently.
d) are surrounded by a double membrane.

The answer is C. The symbiotic relationship has evolved for so many years such that the two are obligate symbiotes and cannot function normally without the other. Chloroplast and mitochondria are believed to have been once free-living bacteria according to endosymbiosis theory.

economic impact of malaria is estimated to cost africa $12 billion every year. this figure factors in costs of health care, absenteeism, days lost in education, decreased productivity due to brain damage from cerebral malaria, and loss of investment and tourism.

volcanoes (an event in the geosphere) release a large amount of particulate matter into the atmosphere. these particles serve as nuclei for the formation of water droplets (hydrosphere). rainfall (hydrosphere) often increases following an eruption, stimulating plant growth (biosphere).