TLS Online TPP Program

#Question id: 31308


Which position of cytosine gets protonated at pH 3?

#Unit 3. Fundamental Processes
  1. N1
  2. N3
  3. C4
  4. C5
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TLS Online TPP Program

#Question id: 11257

#Unit 10. Ecological Principles

Close examination of the yucca-yucca moth mutualism has shown that what appear to be coevolved traits may have been __________ that were critical to the establishment of the mutualism in the first place.

TLS Online TPP Program

#Question id: 34138

#Unit 7. System Physiology – Animal

Which of the following hormones are nanopeptides with a disulfide ring at one end?

TLS Online TPP Program

#Question id: 1520

#Unit 1. Molecules and their Interaction Relevant to Biology

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?

TLS Online TPP Program

#Question id: 12434

#Unit 10. Ecological Principles

Nitrifying bacteria participate in the nitrogen cycle mainly by

TLS Online TPP Program

#Question id: 18716

#Unit 13. Methods in Biology

Function of B-mercaptoethanol in SDS-PAGE is