Two characteristics in flour beetles (Tribolium castaneum) are body colour and antenna shape.

Body colour is determined by a gene with two alleles:

• Allele $B$ is dominant and results in a black body.
• Allele $b$ is recessive and results in a grey body.

Antenna shape is determined by a gene with two alleles:

• Allele $A$ is dominant and results in clubbed antennae.
• Allele $a$ is recessive and results in filamentous antennae.

The two genes are located on different chromosomes.

Two beetles are crossed:

• One parent beetle has a black body and clubbed antennae, and is heterozygous for both genes.
• One parent beetle has a black body and filamentous antennae, and is heterozygous for the $B/b$ gene.

Complete the following details to show this genetic cross: