A sperm cell and an egg cell combine to form a cell called a zygote. This zygote undergoes cellular division repeatedly to become an organism composed of many different kinds of cells. These different types of cells, for example immune cells and blood cells, all arise from the original zygote, but all have different structures and functions. This describes the process of:

If all prokaryotes on earth suddenly vanished, which of the following would be the mostlikely and most direct result? a) the number of organisms on earth would decrease by 10—20%.b) human populations would thrive in the absence of disease.c) bacteriophage numbers would dramatically increase.d) the recycling of nutrients would be greatly reduced, at least initially.e) there would be no more pathogens on earth.