State the cell theory and briefly describe 3 exceptions.

The cell theory states that:All living organisms are composed of cells (unicellular or multicellular)The cell is the smallest unit of lifeAll cells come from the division of pre-existing cellsExceptions:Skeletal muscle: composed of muscle fibres which are much larger than most cells (length: > 300 mm) and each fibre contains hundreds of nuclei (i.e. muscle cells fuse to form muscle fibres)Aseptate fungal hyphae: The building blocks of fungi are hyphae. Hyphae are long filamentous tube-like structures which can be divided into cellular compartments by walls called septa. Some other fungi lack septa and are aseptate fungi. Hence, the hyphae are long undivided structures of cytoplasm with many nuclei.Giant Algae (e.g. Acetabularia): Despite being unicellular it grows to very large sizes (it may be > 7 cm long)