genotypes and phenotypes

The purpose of this lab is to understand how each offspring inherits its genotype and how its phenotype reflects it. Sex chromosomes determine the sex of the offspring, and the autosomes consist of all the other chromosomes that determine phenotypic traits. Dominant traits are the genes that are expressed, while the recessive traits are masked by the dominant traits. We used Drosophila melanogaster (fruit fly), mutating the female fruit fly with a scalloped gene to change the phenotype of its offspring and using males with genes showing wild-type.

Placing WT males and SD females in the same vile, we provided the flies an atmosphere to mate, giving us offspring with mixed genotypes and phenotypes. This experiment will reflect the breeding of fruit flies and how genes are present within adults as well as passed down through the offspring. Our four hypotheses related to mode of inheritance that was used to pass the gene. The mode of inheritance for the scalloped gene is autosomal dominant. The genotype of the female parent is homozygous dominant. The male parent genotype is homozygous recessive.

From this hypothesis we expect all of the offspring to have a heterozygous genotype, and the offspring would all be scalloped…. The mode of inheritance for the scalloped gene is autosomal recessive. The genotype of the female parent is homozygous recessive. The genotype of the male parent is homozygous dominant. From the hypothesis we can expect the offspring to have heterozygous genotypes, but the offspring’s phenotype would be wild type…. The mode of inheritance for the scalloped gene is sex-linked dominant. The genotype of the female is homozygous dominant.

The genotype of the male parent is hemizygous recessive. From this hypothesis we can expect all the female offspring to be heterozygous and all the male offspring to be hemizygous dominant. Both male and female offspring would be scalloped….. Finally, the mode of inheritance for the scalloped gene is sex-linked recessive. The genotype of the female parent is homozygous recessive. The genotype of the male parent is hemizygous dominant. From this hypothesis we can expect all the females to have heterozygous genotypes and all the male offspring to have hemizygous recessive genotypes.

In this prediction, all the male offspring would be scalloped, while the females would be wild type….. The hypothesis that stated the mode of inheritance for the scalloped gene is autosomal dominant, and the mode of inheritance for the scalloped gene is sex-linked dominant predicted that all of the offspring are scalloped. To set up the reciprocal cross, the mutant gene was given to the male rather than the female from the first experiment and the female received the wild-type. The first hypothesis stated was that the mode of inheritance for scalloped is autosomal dominant.

In this hypothesis the female genotype was homozygous recessive while the male’s was homozygous dominant. The offspring from this cross had heterozygous genotypes and expressed the mutant phenotype. …. The mode of inheritance for scalloped is autosomal recessive. In this cross, the male parent had a homozygous recessive genotype, while the female had a homozygous dominant genotype. The result of this was that all of the offspring had a heterozygous genotype and expressed the wild type phenotype. … The mode of inheritance for scalloped is sex linked dominant.

In this cross the female parent had a homozygous recessive genotype while the male had a hemizygous dominant genotype. The female offspring from this cross were heterozygous and expressed the mutant phenotype, while the male offspring had a hemizygous recessive genotype and expressed the wild type phenotype. … The mode of inheritance for scalloped is sex linked recessive. In this cross, the female parent had a homozygous dominant genotype while the male parent had a hemizygous recessive genotype. The female offspring of this cross had a heterozygous genotype while the males had a hemizygous dominant genotype.

All offspring expressed the wild type phenotype…. Each of the Punnett squares are possible outcomes of offspring phenotypes based on the genotypes of the parents. By comparing our results to that of the Punnett square’s we will be able to determine, through process of elimination, whether or not the mutation is a dominant or recessive trait and if it appears through an autosomal or sex linked chromosome. Based on the phenotypes of the offspring, we can infer the identifications of the parental genotypes.