#Question id: 2344
#Unit 2. Cellular Organization
The release of insulin from certain human cells is an example of
#Question id: 4977
#Unit 11. Evolution and Behavior
There are at least a dozen known species in the extinct genus Lystrosaurus. If each species was suited to a quite different environment, then this relatively large number of species is likely due to
#Question id: 11169
#Unit 10. Ecological Principles
The viceroy butterfly (limenitis archippus) resembles the queen butterfly (danaus gilippus), a species toxic to birds because of alkaloids it stores during larval development from the milkweeds it feeds upon. The viceroy butterfly is an example of what kind of defense against predation?
#Question id: 1520
#Unit 4. Cell Communication and Cell Signaling
Following statements are regarding to enzymatic processing of benzo(a)pyrene to a more potent mutagen and carcinogen.
A. Liver enzymes, particularly P-450 enzymes, modify benzo(a)pyrene in a series of reactions, producing 7,8-diol-9,10-epoxide, a highly potent mutagenic species that reacts with DNA primarily at the N2 atom of a guanine base.
B. The adduct, (+)-trans-anti-B(a)P-N2-dG, causes polymerase to insert an A rather than a C opposite the modified G base. Next time the DNA is replicated, a T will be inserted opposite the A, and the mutation will be complete.
C. Potent mutagen majorly causes conversion of guanine (G) to thymine (T) bases, a transition mutation.
D. When this potent mutagen applied to cultured bronchial epithelial cells, activated benzo(a)pyrene induces many mutations, including activating mutations at codons 175, 248, and 273 of the p53 gene.
Which of the following statements are correct?
#Question id: 162
#Unit 1. Molecules and their Interaction Relevant to Biology
All of the amino acids that are found in proteins, except for proline, contain a(n):