Hundreds of people danced and sang in a noisy demonstration in Rio de Janeiro on Saturday, as hundreds of thousands marched globally against the U.S. biotechnology giant Monsanto and its genetically modified crops and pesticides. One of the corporation’s major products was recently classified as “probably carcinogenic to humans” by the World Health Organization. Demonstrators are demanding a 10-year moratorium on the planting of Monsanto seeds so that independent research can be conducted into the effects of the technology. teleSUR