Read the following statements and choose the follwoing option: 1. The number of mitochondria per cell is constant 2. The adjacent triplets of peripheral fibrils are not linked 3. The central part of the centriole is proteinaceous 4. The isolated lysosomal vesicles have been found to be very rich in almost all types of hydrolytic enzymes 5. The enzymes of lysosyme work at only acidic pH