Question: In Drosophila melanogaster, eyeless (ey) is a recessive trait in which the eyes are tiny or absen…

In Drosophila melanogaster, eyeless (ey) is a recessive trait in
which the eyes are tiny or absent. The ey locus is found on
chromosome 4. Monosomy and trisomy for this very small chromosome
are compatible with survival and fertility. A trisomic
wild-type male with the genotype ey+ ey+ ey is crossed to
an ey+ ey female. Assuming random segregation of
chromosomes into gametes, determine the chromosome constitution and
phenotypic ratios in the offspring.

Please show how to get the answer and use the forked-line
method/branching diagram to solve the problem.

Thank you!