Q1. The different strains of Chlorella are morphologically indistinguishable. Consequently, which of these would be the best test to perform on Chlorella, both before and after re-establishment of zoochlorellae, to find out which Chlorella strains had been maintained within P. bursaria?

Q2. Can genotype for a gray-bodied fly be determined? Why or why not? Explain all of the possible genotypes for a fly with that phenotype.

Q3. In a population of 1000 individuals, 510 show the dominant phenotype. How many individuals would you expect of each of the possible three genotypes for this trait?