Answer:
1. commensalism "Aerobic bacteria in the human colon consume oxygen, making it possible for anaerobic species to survive"
2. mutualism "Flagellates live in the gut of termites, feeding on the wood consumed by the termite and allowing the termite access to nutrition and energy in wood that they could not otherwise digest"
3. parasitism "A helminth takes up residence in a human digestive tract, consuming nutrients"
4. amensalism "A mold produces a chemical that kills bacteria without apparently benefiting"
Step-by-step explanation:
1. commensalism: one species benefits while the other species neither benefit nor prejudiced
2. mutualism: two species benefit
3. parasitism: one species benefits while the other species is prejudiced
4. amensalism: one species is unaffected while the other species is prejudiced