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Test: ACT Science
Drosophila melanogaster, the common fruit fly, is frequently utilized for genetic studies due to its simple food requirements, hardy nature, and because it completes its life cycle within 12 days at room temperature. This particular fly species has four pairs of chromosomes with traits that have been studied and observed to be inherited in a Mendelian fashion.
The predictive capacity of Mendelian genetics depends on traits whose physiological characteristics, know as phenotypes, are determined by genetic combinations of alleles, known as genotypes. The exhibition of observable traits is determined by the combination of two alleles for a specific characteristic. For example, the dominant allele for the wild type red eye color is E and the recessive sepia-brown color is e. Likewise, the dominant allele for long wings is W and the recessive allele for short wings is w. When a dominant allele is present with a recessive one, the organism physically exhibits the trait of the dominant allele and the organism is known as heterozygous for that trait. If an organism has two dominant or two recessive alleles for a particular trait, it is known as homozygous for that trait. Only when two recessive alleles are present does the organism physically exhibit the trait of the recessive allele. Heterozygous individuals are often known as carriers because the dominant allele phenotype masks the recessive allele phenotype and the organism can carry the recessive allele without exhibiting any of its physical traits.
Study 1
A researcher wants to study the inheritance of eye color in fruit flies. The scientist mates a homozygous recessive (ee) group with a homozygous dominant (EE) group in order to obtain the F1 Generation. Two members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 1).
Table 1
Study 2
A researcher decided to perform a dihybrid cross of fruit flies possessing red eyes and long wings with fruit flies possessing sepia-brown eyes and short wings. The scientist bred homozygous dominant flies with homozygous recessive flies in the F1 Generation. The members of the F1 Generation were then mated in order to obtain the F2 Generation (Table 2).
Table 2
| 1. | Drosophila melanogaster is commonly known as which of the following? |
Gnat
Flea
House fly
Fruit fly
