Which of the following parameter is not generally use to measure the growth?

Growth is the process of that involves an increase in the cell size and cell number. There are various parameters which are used to measure the growth. The commonly used parameters include measurement of length, cell number, weight, volume, diameter, surface area. Length can be measured using a microscope or auxanometer. Growth can be measured in terms of weight as fresh weight and dry weight. Also, when a cell increase, there is an increase in the protoplasm. However, measuring the protoplasm content is not generally used to measure the growth. 
Thus, the correct answer is 'Increases in protoplasm.'