The 7 (sometimes 8) characteristics of life are:
1. living things are composed of cells
2. living things have different levels of organization
3. living things metabolize (i.e. use energy)
4. living things respond to their environment
5. living things grow
6. living things reproduce
7. living things adapt to their environment
(some sources include) 8. living things have genetic material
Viruses do not metabolize, they do not grow, they do not adapt to their environment, and they cannot reproduce independently; viruses require host cells to reproduce and perform the other functions that give them the appearance of aliveness.
Answer:
"Macrophages" cells are commonly dispersed (mixed in) with simple columnar epithelial cells. They are responsible for secreting mucus.
Explanation:
I know they carry diseases which can harm or kill the animal it is attached to. These diseases can taint the meat of the animal so it wouldn't be wise to eat it which stinks if the animal is bread for eating. They can also irritate the skin and cause rashes, or even eat the flesh of the animal away.