Dear student ,
Yeast can use oxygen to release the energy from sugar in the process called "respiration". So, the more sugar there is, the more active the yeast will be and the faster its growth .
Molds grow from tiny spores that float around in the air. When some of these spores fall onto a piece of damp food or other materials, they grow into molds. The molds that grow in your mold terrarium feed on the bread, cheese, and other foods .
Regard