A
1 and 2 only
B
2 and 3 only
C
1 and 3 only
D
1, 2 and 3
Correct answer: (a) 1 and 2 only
Explanation
- A
1 and 2 only
1 and 2 only. Bacteria and fungi grow on synthetic media. Viruses need living host cells.
- B
2 and 3 only
2 and 3 only. Viruses fail the artificial-medium test.
- C
1 and 3 only
1 and 3 only. Same miss on virus.
- D
1, 2 and 3
All three. Virus cannot be cultured on agar alone.
Summary. Official key is (a) 1 and 2 only. Bacteria and fungi take artificial media. Viruses are obligate intracellular — they are grown in eggs, cell lines or animals, not on a flask of broth alone.