#Question id: 15155
#Unit 8. Inheritance Biology
In this problem we will explore some of the many ways that mutations in two different genes can interact to produce different Mendelian ratios. Consider a hypothetical insect species that has red eyes. Imagine mutations in two different unlinked genes that can, in certain combinations, block the formation of red eye pigment yielding mutants with white eyes. In principle, there are two different possible arrangements for two biochemical steps responsible for the formation of red eye pigment. The two genes might act in series such that a mutation in either gene would block the formation of red pigment. Alternatively, the two genes could act in parallel such that mutations in both genes would be required to block the formation of red pigment.
Further complexity arises from the possibility that mutations in either gene that lead to a block in enzymatic activity could be either dominant or recessive. If the crosses between a wild type insect with red eyes and a true breeding white eyed strain with mutations in both genes. Such considerations yield the Pathways in parallel with dominant mutations in both genes, determine the phenotype of the F1 progeny and the expected phenotypic ratio of red to white eyed insects in the F2.
#Question id: 15303
#Unit 4. Cell Communication and Cell Signaling
#Question id: 10943
#Unit 7. System Physiology – Animal
An 8-year-old male is frequently coming to the clinic for persistent skin infections that do not heal within a normal time frame. He had a normal recovery from the measles. Checking his antibodies following immunizations yielded normal antibody responses. A defect in which of the following cells would most like be the cause of the continual infections?
#Question id: 15725
#Unit 11. Evolution and Behavior
Alfred Russel Wallace (1823–1913), who was collecting specimens in the Malay Archipelago, had independently conceived that
#Question id: 10451
#Unit 6. System Physiology – Plant
Which induction is responsible for “uncages” the kinase domain of phototropin and leads to autophosphorylation