The Monod growth function r(N) describes growth as a function of nutrient concentration N. Assume that r
(
N
)
=
5
N
1
+
N
,
N
≥
0.
r(N)=5
1+N
N

,N≥0. Find the percentage increase when the nutrient concentration is doubled from N = 0.1 to N = 0.2. Compare this result with what you find when you double the nutrient concentration from N = 10 to N = 20. This is an example of diminishing return.