Q2: For any drosophila population, what is the proportion of live homozygous (Cy/Cy) flies? Explain. Solution The proportion of live homozygous (Cy/Cy) flies in a drosophila population will be 0.This is because Cy acts as a mutation that is recessive and lethal.In homozygous condition,Cy/Cy flies will die even before they will reach the adult stage..