Fungicides and antibiotics are chemicals that:

Several South Indian states raise 2-3 crops of rice annually. The agronomic feature that makes this possible is because of

1. shorter rice plant

2. better irrigation facilities

3. early yielding rice variety

4. disease-resistant rice variety

To isolate protoplast, one needs:

1. pectinase

2. cellulase

3. both pectinase and cellulase

4. chitinase.