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.
Concept 5: Prophase. Chromosomes become visible, the nucleolus disappears, the mitotic spindle forms, and the nuclear envelope disappears. To see prophase animated, click the image. Chromosomes become more coiled and can be viewed under a light microscope. Each duplicated chromosome is seen as a pair of sister chromatids joined by the duplicated but unseparated centromere. The nucleolus disappears during prophase.