Certain parts of the brain govern specific functions. For example, the cerebellum is involved with coordination; the hippocampus with memory. Nerve cells (neurons) are the basic unit of communication in the brain.
Eukaryotic organisms use mitosis to reproduce sexually. In mitosis, the parent cell is divided into two daughter cells which be identical to the parent cell. Edit
Of course single celled organisms reproduce. If their organisms they reproduce, that is a key concept in defining what a living organism is. For example bacteria reproduce asexually by budding. The amoeba, a protist will reproduce by binary fission.In essence they just kind of break apart after DNA replication. just now. Report Abuse. Single cell organisms do reproduce, just not the same way-most-multicellular organisms do. Basically they go through a process called mitosis, or meiosis if they are sex cells (cells with half the chromosomes of regular cells).