Which of the following is responsible for the beginning of the detritus food chain?

In which layer of soil does decomposition occur at the maximum rate?

Decomposition is defined as .....

Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as . . . . . . .

In decomposition,detritivores break down detritus into smaller particles. This process is called......

Which of the following statements is true regarding humus?
$(P)$ It contains colloids.
$(Q)$ It contains nutrients.
$(R)$ Its decomposition is not possible.