Respuesta :
virus. it's only living when it enters a host's body as it's a parasitic organism
Answer:
virus
Explanation:
Viruses are considered organisms at the limit of life. On the one hand they resemble organisms that have genes and evolve by natural selection and reproduce by creating multiple copies of themselves. However, they lack cellular structure, which is the pillar of life. It can only multiply within the cells of other organisms.