Growth and nutrient uptake in batch cultures of the freshwater diatom, Cyclotella meneghiniana, are studied under silicate-limiting conditions. Unbuffered freshwater medium containing 25 M silicate is inoculated with cells. Samples are taken over a period of 4 days for measurement of cell and silicate concentrations. The results are as follows. Cell Concentration Silicate Concentration Time (days) (cells 1-1) (M) 4.41 x 105 5.53 x 105 1.31 x 106 3.00 x 106 4.82 x 106 1.12 x 107 1.67 107 2.57 x 107 8.00 0.5 7.97 1.0 7.72 1.5 7.59 2.0 6.96 2.5 5.33 3.0 4.63 4.0 1.99 (a) Does this culture exhibit exponential growth? (b) What is the value of Hmax? (c) Is there a lag phase? (d) What is the observed biomass yield from substrate? (e) Is the observed biomass yield from substrate constant during the culture?