Viruses are not cells but they are organisms. An organism has a life cycle. Each organelle carries out a specific task for the cell. Eukaryotes have many organelles. Prokaryotes have fewer organelles.
Most viruses have only two organelles.
Cell biology studies the organelles of cells and viruses. How radiation dose and exposure determine survival from atomic explosions and accidents. Some organism have two lives, a diploid and a haploid phase of their life cycle. Sperm and eggs are produced by a process of meiosis. There are two cell divisions involved, reduction division and equation division.