Final answer:
Epistasis is the genetic term that best describes the observed phenomenon in Drosophila where the bristles that develop from the epidermis are evenly spaced and two bristles never occur immediately adjacent to each other. Epistasis is a type of gene interaction in which one gene masks or interferes with the expression of another gene.
Step-by-step explanation:
Epistasis is the genetic term that best describes the observed phenomenon in Drosophila where the bristles that develop from the epidermis are evenly spaced and two bristles never occur immediately adjacent to each other. Epistasis is a type of gene interaction in which one gene masks or interferes with the expression of another gene. In this case, the spacing of the bristles is controlled by the interaction between multiple genes.
For example, in Drosophila, the presence of one gene may prevent the formation of a bristle in a certain location, resulting in the observed even spacing. If another gene is present, it may interact with the first gene to ensure that two bristles never occur right beside each other.
Epistasis can also occur in other organisms and for different phenotypic traits. It is a common genetic phenomenon that helps explain the complexity of gene interactions and the diversity of phenotypes seen in nature.
The term that describes the even spacing of bristles in Drosophila is epistasis, where one gene masks the expression of another. This is illustrated in mice and plants through the control of pigmentation and seed shape, respectively.
The genetic term that best describes the observed phenomenon in Drosophila where the bristles that develop from the epidermis are evenly spaced and two bristles never occur immediately adjacent to each other is epistasis. This is a genetic interaction where one gene masks or interferes with the expression of another gene. In the context of Drosophila, although not directly stated in the question, it suggests that there might be an epistatic interaction ensuring that the genes responsible for bristle formation inhibit the formation of bristles in immediately adjacent positions. This leads to the even spacing of bristles.
An example of epistasis can be seen in mice, where a separate gene is necessary for pigment production. In instances where the cc allele is present, it's epistatic to other genes that determine coat color, resulting in an albino phenotype regardless of the alleles at the coat color locus. Similarly, in the shepherd's purse plant, the presence of a dominant A or B allele results in triangular seeds, showing a dominant epistatic relationship where one gene suppresses the expression of another, leading to a particular phenotype over another.