Nucleus
Nucleus (head quarter of cell) It is discovered by Robert brown in 1831. It is a Greek word which mean karyon in orchid cell. Nucleus is considered as controller or director of cell. Nucleus is a double membrane bound organelles which control all cellular metabolic activity and contain genetic information. Number Same cell can absent nucleus called Enucleated cell. EXAMPLE - Human RBCs, Sieve tube, Cell platelets. Almost all eukaryotic cell have only one nucleus is called Uninucleated cell like Animal cell. Having two nucleus is called by nucleated cell is called Binucleated cell.EXAMPLE - Paramecium(2 nucleus-> 1. Macronucleus 2. Micronucleus) Contain more than two nucleus is called Multinucleated cell.EXAMPLE - Opilina, skeleton muscle cell. Position of nucleus : Centric - Nucleus present in centre of cell. EXAMPLE - Almost all animal cell. Ecentric - Nucleus is sh...