Final answer:
Plants with ant colonies were found to grow faster and have a higher survival rate in Janzen's study where ants were removed from acacia plants.
Step-by-step explanation:
In Janzen's study where ants were removed from acacia plants, plants with ant colonies were found to grow faster and have a higher survival rate than plants without ants.
This is because ants provide protection against herbivores and help with pollination.