In the Fruit Fly Drosophila melanogaster, wings (A) are dominant over a lack of wings (a) and red eyes (E) are dominant over sepia (brownish) eyes (e). A wingless fly that is heterozygous for eye color is crossed with a fly that is heterozygous for both eye color and presence of wings. What are the genotype and phenotypic ratios for this cross? What fraction of the offspring from this cross will be wingless and have sepia eyes? What fraction will have the genotype AaEe?

Growth of chest hair, deepening of the voice, and muscle growth are secondary sex characteristics. which most likely affects the development of these traits? testes ovaries prostate gland vulva

In iceland, the mid atlantic ridge runs through the center of the contry. what can you conclude about the apperence of iceland many thousands of years from now?

Keeping in mind the life cycle of bacteriophages, consider the following problem: during the reproductive cycle of a temperate bacteriophage, the viral dna inserts into the bacterial chromosome where the resultant prophage behaves much like a trojan horse. it can remain quiescent, or it can become lytic and initiate a burst of progeny viruses. several operons maintain the prophage state by interacting with a repressor that keeps the lytic cycle in check. insults (ultraviolet light, for example) to the bacterial cell lead to a partial breakdown of the repressor, which in turn causes the production of enzymes involved in the lytic cycle. as stated in this simple form, would you consider this system of regulation to be operating under positive or negative control?