(a) The yeast cells fail to multiply in water but they multiply rapidly in sugar solution. Give one reason for it.
(b) Why dies bread mould grow profusely on a moist slice of bread but not on a dry slice of bread?

Answer

(a) Water does not provide any energy to yeast cells So, Yeast cells fail to multiplying in water due to inadequate energy in its cells. Sugar provides energy to yeast cells to cary out reproduction by multiplying rapidly (b) Moisture is necessary for the growth of bread mould. The moist slice of bred provides both moisture and nutrients but no moisture. So in the absence of moistrue, bread mould does not grow on the dry slice or bread.