Sunny weather does seem to be broadly correlated with a larger surplus on the international tourism balance, while worse weather is associated with a tourism deficit. This confirms that, as expected, overall there is a net flow of tourists from colder to warmer countries.
Endosymbiotic theory is a theory of evolution that eukaryotes came from prokaryotes. Mitochondria and chloroplasts both have the double membranes. Each of them also contain genetic material that are replicated with a separate cell cycle. Both organelles have their own ribosomes.
