Why the number of micro-organisms in the river increased after raw sewage was accidentally released into the river?

What re the two main phrases of the cell cycle.

In sexual reproducing animals once fertilization of the egg takes place, the exists as a single cell until cell division begins. a) egg b) larva c) sperm d) zygote

Which of the following is a period in the paleozoic era? devonian cambrian permian all of the above