#Question id: 12422
#Unit 10. Ecological Principles
#Question id: 4234
#Unit 3. Fundamental Processes
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the __.
#Question id: 4651
#Unit 11. Evolution and Behavior
Some members of a photosynthetic plant species are genetically resistant to an herbicide, while other members of the same species are not resistant to the herbicide. Which combination of events should cause the most effective replacement of the non-herbicide-resistant strain of plants by the resistant strain?
1. The presence of the herbicide in the environment
2. The absence of the herbicide from the environment
3. The maintenance of the proper conditions for one generation
4. The maintenance of the proper conditions for many generations
#Question id: 732
#Unit 1. Molecules and their Interaction Relevant to Biology
Ramachandran plots can help increase the accuracy of models derived from x-ray crystallography data. The plot below was created by measuring phi, and psi for each amino acid residue in a 2.2 A resolution crystal structure. In the plot, which excludes Gly and Pro residues, selected residues (dots) are numbered 1 through 5.
Which of the following statements can be correctly stated for this plot in reference to selected residues?
A. Residues 1 and 3 are in either B sheets
B. residue 2 is in a right-handed a helix, and residue 4 is in a left-handed a helix.
C. If residue 5 were Gly, it might be in an acceptable position in the plot
#Question id: 1447
#Unit 4. Cell Communication and Cell Signaling
A patient with B cell leukemia donates some cancer cells for analysis. The cells do not contain the usual chromosomal translocations associated with leukemia. Instead, a sporadic mutation seems to have arisen in a certain gene, followed by loss of heterozygosity in the second copy. This gene product is most likely: