What is sludge? Explain how it is treated.

Explain how soil is formed.

What is roasting ? Explain.

What is dialysis ? Explain ?

What is a reflex are? Explain how it carries the signals from receptor to effectors?

Explain how DNA is isolated from cells.

What are chromosomes? Explain how in sexually reproducing organisms the number of chromosomes in the progeny is maintained.

What is menstruation? Explain.

Explain how forests prevent floods.

What is calcination? Explain.