CELPIP Reading Part 3Reading for Information Practice

A. A small number of forest fungi produce visible light in their fruiting bodies, threadlike networks, or both. The glow is usually easier to notice after darkness because it is far weaker than daylight or artificial illumination. Bioluminescence occurs in scattered fungal groups rather than in every species growing on decaying wood. Depending on the fungus, the light may continue for hours when temperature, moisture, and oxygen remain suitable. Together, these details place bioluminescence in forest fungi within a broader pattern shaped by the surrounding environment over a meaningful period of time.

B. Fungal light comes from a chemical reaction involving a light-producing compound, an enzyme, and oxygen. Energy released during the reaction appears mainly as light rather than as a noticeable increase in heat. The process is controlled within living cells, so drying or severe damage eventually stops the glow. Its colour commonly appears greenish because the reaction releases energy within a limited range of visible wavelengths. This combination helps explain why the chemical production of light cannot be understood from one feature alone or from one brief observation.

C. One proposed function is attracting night-active insects that may carry fungal spores to new material. Glowing networks inside wood might also discourage animals that would otherwise eat or disturb the fungus. However, not every luminous species has bright fruiting bodies, and the same explanation may not fit them all. Scientists therefore treat several ecological purposes as possibilities instead of assuming one universal benefit. For bioluminescence in forest fungi, relationships among these features matter because a change in one may influence several others within the same setting over time.

D. Finding luminous fungi can be difficult because suitable specimens may look ordinary when viewed during the day. Observers often allow their eyes to adjust fully before checking damp logs in a naturally dark setting. Laboratory work can compare glowing and non-glowing tissues while controlling oxygen, temperature, and other conditions. Researchers also examine related species to understand when light production appeared or disappeared during fungal evolution. Viewed together, details about observation challenges and research methods connect visible characteristics with processes that are less immediately obvious to an ordinary observer at first.

E. Not given in any of the above paragraphs.