Conversion of a proto-oncogene into an oncogene, also called activation, generally involves a gain-of-function mutation. Following statements are regarding to the mechanisms that produce oncogenes from the corresponding proto-oncogenes.

A. A change in a single base pair in a proto-oncogene that results in a hyperactive or constitutively active protein product.

B. A chromosomal translocation that fuses two genes together to produce a hybrid gene encoding a chimeric protein whose activity, unlike that of the parent proteins, is permanently suppress.

C. A chromosomal translocation that brings a growth regulatory gene under the control of alternative enhancers that cause inappropriate expression of the gene.

D. Amplification of a DNA segment including a proto-oncogene so that numerous copies exist, leading to overproduction of the encoded protein.

Which of the following statements are correct?

#Question id: 731

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following structure is mentioned in the given Ramachandran plot

#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: 733

#Unit 1. Molecules and their Interaction Relevant to Biology

Which one of the statements on protein conformation, detailed below is INCORRECT?

#Question id: 734

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following statements is true for two different tripeptides consisting of either glycine or proline?

#Question id: 735

#Unit 1. Molecules and their Interaction Relevant to Biology

The a-keratin chains indicated by the diagram below have undergone one chemical step. To alter the shape of the a-keratin chains—as in hair waving—what subsequent steps are required?

#Question id: 736

#Unit 1. Molecules and their Interaction Relevant to Biology

The most important contribution to the stability of a protein’s conformation appears to be the: