These are the brain, heart, kidneys, liver, and lungs. The human brain is the body's control center, receiving and sending signals to other organs through the nervous system and through secreted hormones.
For the beetle genus, see Coprini. Synapsis (also called syndesis) is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I of meiosis.
Once cell division is triggered, the DNA inside the nucleus duplicates and the chromatin within the cells nucleus begins to condense. Prior to prophase, DNA is visible under a light microscope as a dark blur. Before prophase, a normal cell contains 23 pairs of chromosomes. After prophase, the cell contains 46 pairs of chromosomes -- two copies of each pair -- known as sister chromatids, joined at a centromere to form an X-shape.