Final answer:
To determine the phenotypes and genotypes resulting from the crossing of two black flies, we can use Punnett squares and Mendel's principles of inheritance. The genotypes of the parent flies are heterozygous (Bb). The phenotypes of the offspring will be 3:1 for black:white.
Step-by-step explanation:
To determine the phenotypes and genotypes of the offspring resulting from the crossing of two black flies, we need to understand the principles of inheritance.
In this case, the cross appears to follow a monohybrid pattern, meaning that the flies differ only in one characteristic: color.
According to Mendel's principles, each parent contributes one of two unit factors to each offspring, and all possible combinations are equally likely.
From the given information, we can determine that the genotypes of the parent flies are both heterozygous, represented as Bb.
The phenotypes of the offspring can be determined using a Punnett square. In this case, a Punnett square with two rows and two columns would result in four squares.
Each square represents a possible combination of the parents' alleles.
The genotypes that can be formed are BB, Bb, Bb, and bb. From this, we can determine that the genotype ratio is 1:2:1 for BB:Bb:bb.
The phenotypes can be determined by knowing that the black color is dominant over the white color, so BB and Bb both result in a black phenotype, while bb results in a white phenotype.
Therefore, the phenotype ratio is 3:1 for black:white.