Question

Which statement describes the critical distinction between arbuscular mycorrhizae and ectomycorrhizae?

1) Ectomycorrhizae involve more penetration into root cells.
2) Arbuscular mycorrhizae often grow farther into soil and involve more penetration into root cells.
3) Arbuscular mycorrhizae form a mantle around root exteriors, whereas ectomycorrhizae only grow between root cells.
4) Arbuscular mycorrhizae are engaged in commensalisms, whereas ectomycorrhizae are engaged in mutualisms.

Answer 1

Ectomycorrhizae form a dense sheath around roots and extend hyphae into the soil, while arbuscular mycorrhizae embed their mycelium within the root tissue and penetrate the root cells to form arbuscules for metabolic exchanges. The correct answer is option 1) Ectomycorrhizae involve more penetration into root cells.

Step-by-step explanation:

The critical distinction between arbuscular mycorrhizae and ectomycorrhizae lies in their physical interactions with plant roots. Ectomycorrhizae form a dense sheath around the roots, called a mantle, and extend hyphae into the soil, enhancing water and mineral absorption.

On the other hand, arbuscular mycorrhizae, also known as endomycorrhizae, do not form a dense sheath but rather embed their mycelium within the root tissue. The hyphae of arbuscular mycorrhizae penetrate the root cells, forming a branched structure called an arbuscule. This allows for metabolic exchanges between the fungi and host plant.