Because it undergoes Mitosis where the chromosomes of a certain cell copies it's own and then split to form another cell or daughter cell. But note that only body cells act that way. Sex cells works differently that's why siblings don't look exactly the same even though they have the same parents. Only in mitosis where the quality and quantity are the same. but not in meiosis.
Clostridium botulinum are rod-shaped bacteria (also called C. botulinum. They are anaerobic, meaning they live and grow in low oxygen conditions. The bacteria form protective spores when conditions for survival are poor