Answer:
100 %
Explanation:
Dominance is a genetic phenomenon where a gene variant or allele masks the effects of another allele (of the same gene) in heterozygous individuals. This last gene variant is referred to as the recessive allele. In this case, the silkworm mother can produce only one type of gamete carrying the dominant gene (B) form, while the silkworm father can produce only one type of gamete carrying the recessive gene (b) form. In consequence, from this cross, all offspring (100 %) will be heterozygous (Bb) and therefore they will express the dominant trait (i.e., yellow cocoon).