Simplify the following text for a Grade 13 native English-speaking person.
Original: The two types are differentiated by the fact that the hyphae of ectomycorrhizal fungi do not penetrate individual cells within the root , while the hyphae of endomycorrhizal fungi penetrate the cell wall and invaginate the cell membrane .
Simplified: The hyphae of ectomycorrhizal fungi do not penetrate individual cells within the root , while the hyphae of endomycorrhizal fungi penetrate the cell wall and invaginate the cell membrane .