Which statement about mycorrhizal associations is true regarding root tips?

• A. Increase leaf size
• B. Decrease water uptake
• C. Extend life to root tips and inhibit invasion of damaging fungi
• D. Cause root rot

Answer: (C)

Mycorrhizal associations form a symbiotic partnership where fungal networks attach to and extend from root tips, greatly expanding the root’s ability to explore soil. This expanded network enhances water and nutrient uptake, especially phosphorus, and helps plants stay healthier under stress. Importantly, the fungi act like a protective shield around the root tips—outcompeting harmful microbes, producing antimicrobial compounds, and physically occupying niches that pathogens might otherwise invade. So, root tips live longer and are better defended against damaging fungi thanks to this collaborative rooting system. The other statements don’t fit because leaf size is not driven by root tips, water uptake is typically increased rather than decreased, and mycorrhizal activity generally helps resist root pathogens rather than cause root rot.