Question

question 25
match the description to the infectious agent.
column a

1. tiny, single - celled organisms with no nucleus inside the digestive track
2. no cells, takes over a host cell from which it replicates and spreads into neighboring host cells
3. multicellular organisms made up of cells that have cell walls and well - defined nuclei
4. an organism that lives in or on another organism and takes nutrients at the expense of the host.

column b
a. viruses
b. parasite
c. fungi
d. bacteria

Explanation:

1. Tiny, single-celled prokaryotes (no nucleus) are bacteria.
2. Acellular agents needing host cells to replicate are viruses.
3. Multicellular eukaryotes with cell walls are fungi.
4. Organisms living on/inside hosts for nutrients are parasites.

Answer:

1. d. bacteria
2. a. viruses
3. c. fungi
4. b. parasite