#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: 26832
#Unit 10. Ecological Principles
#Question id: 4710
#Unit 11. Evolution and Behavior
The horizontal axis of the cladogram depicted below is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular. The labeled branch points on the tree (V-Z) represent various common ancestors. Let's say that only since 50,000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species, and only the tips of the lineages on this tree represent distinct species.
Which pair of scientists below would probably have agreed with the process that is depicted by this tree?
#Question id: 28274
#Unit 5. Developmental Biology
In case of sea urchin (Strongylocentrotus purpuratus), the acrosome reaction is initiated by_____
#Question id: 2590
#Unit 2. Cellular Organization
Following graph represents dynamic instability of microtubules in vitro. Identify the correct activity at A, B, C and D.