Question

A group of hikers find a fallen tree in a forest. The dead tree trunk is covered by mushrooms and other fungus. Later, they find a wild apple tree with many apples lying on the forest floor beneath the tree. The apples are all rotten and decayed by bacteria. Which statement BEST summarizes how these fungus and bacteria organisms are obtaining their food energy?
A) The fungus and bacteria are both parasitic organisms that obtain food from other living organisms.
B) The fungus and bacteria are both obtaining their energy by manufacturing food from minerals and sunlight.
C) Both fungus and bacteria require well-fertilized soil in which to obtain nutrients needed for chemosynthesis.
D) The fungus and bacteria organisms are obtaining the energy they need by decomposing organic matter like dead trees and old apples.
Eliminate

Answer 1

The answer is D, bacteria and fungus are both decomposers.

Answer 2

Answer: D. The fungus and bacteria organisms are obtaining the energy they need by decomposing organic matter like dead trees and old apples.

Fungi is the primary decomposer of biological waste in forest ecosystem. Fungi grows on the branching network of hyphae which provide it more penetration potential towards the litter. Wood decaying fungi has enzymes required for decomposition of lignin, a chemical substance found in wood. Fungi decompose organic matter by releasing enzymes which breaks down the decaying matter, after that they absorb the nutrients in the decaying material. The left residue in the organic matter includes sugars and amino acids are degraded and decomposed by the bacteria.