Final answer:
Viruses have two principal life cycles: the lytic cycle where the virus destroys the host cell and the lysogenic cycle where the virus DNA integrates with the host's genome and replicates without causing immediate harm.
Step-by-step explanation:
The Life Cycles of Viruses: Lytic and Lysogenic
The two primary life cycles of viruses are the lytic cycle and the lysogenic cycle. The lytic cycle, also known as the virulent cycle, is characterized by the virus taking over the host cell to reproduce new phages and ultimately causing the lysis and destruction of the host cell. This can be seen in the T-even bacteriophage, which undergoes five stages: attachment, entry, replication, assembly, and lysis. The lysogenic cycle, also described as the temperate cycle, involves the incorporation of phage DNA into the host genome, termed a prophage, which is then passed on to subsequent generations of cells without causing immediate harm.
Environmental stressors may cause a switch from the lysogenic cycle to the lytic cycle, leading to cell destruction. Both cycles play pivotal roles in how viruses propagate and affect their hosts.