The answers are:
a. -/b+
d. b/b+
b+ - the allele for normal bristles
b - the allele for bent pristles
Monosomic means there is only one instead of two alleles in a gene locus.
So, the parents' genotypes are:
monosomic bent bristles: -/b
diploid normal bristles: b+/b+
The following cross is conducted of true-breeding adult flies:
Parents' phenotype: monosomic bent bristles x diploid normal bristles
Parents' genotype: -/b x b+/b+
F1 generation: -/b+ -/b+ b/b+ b/b+
