Passage A
For decades, classical botany viewed plants as passive organisms competing strictly for localized soil nutrients and sunlight. However, recent investigations into subterranean mycorrhizal networks—symbiotic fungal filaments interconnecting the root systems of multiple plants—demonstrate that plants actively transmit biochemical warnings. When a donor plant suffers foliar herbivory by insects, it synthesizes signaling molecules that travel through fungal hyphae to neighboring conspecifics. Receiving plants subsequently upregulate defensive enzymes and volatile deterrents before they experience direct pest infestation. This evidence confirms that mycorrhizal networks facilitate coordinated, inter-organismal communication that enhances collective survival within plant communities.
Passage B
While mycorrhizal networks undeniably physically link root systems across diverse plant species, characterizing the movement of biochemical compounds through fungal hyphae as purposeful communication is empirically premature. Fungal filaments function primarily as transport pathways driven by standard source-sink concentration gradients and passive capillary action. When an herbivore damages a plant, damaged tissues release elevated concentrations of secondary metabolites that naturally diffuse into the surrounding fungal network. Neighboring plants that absorb these diffused compounds merely react to an incidental environmental cue rather than a deliberate, altruistic warning signal. Understanding these interactions requires viewing fungal networks as complex transport conduits rather than intentional communicative systems.
Based on the passages, which of the following statements are supported by both Passage A and Passage B? Select all that apply.
- Subterranean fungal networks establish physical connections between the root systems of separate plants.Cevap
- BThe primary evolutionary purpose of mycorrhizal fungi is to foster cooperative defense among unrelated plant species.
- Plants near an insect-damaged plant can activate defensive mechanisms prior to being directly attacked themselves.Cevap
- DThe movement of compounds through fungal hyphae is governed entirely by passive diffusion gradients rather than active signaling.
- EInsect damage to a plant's foliage permanently destroys its ability to absorb soil nutrients through fungal networks.