All eukaryotic cells have within them a variety of different structures called organelles. Organelles are small and function much like organs function in a large organism. Some organelles are responsible for gathering cell energy, others for controlling cell activities.Note-although this organelle is also found animal cells, the vacuoles from plant cells are drastically bigger and play a much more important role in the processes of the cell.
HIV crossed from chimps to humans in the 1920's in what is now the Democratic Republic of Congo. This was probably as a result of chimps carrying the Simian Immunodeficiency Virus (SIV), a virus closely related to HIV, being hunted and eaten by people living in the area.
Forms of HIV carried by chimpanzees can infect HUMANS: Study supports theory AIDS epidemic started in primates. 1  Researchers studied strains of SIV, considered the ancestor of HIV. 2  First lab evidence that chimp-carried forms of SIV can infect human cells. 3  This backs up hypothesis that SIV was passed from a chimp in 1900s.