Following statements are regarding to the some cancers harbor characteristic chromosome alterations. Chronic myelogenous leukemia (CML), a common leukemia in humans, was found to be associated with the Philadelphia chromosome.

A. Philadelphia chromosome is generated by a translocation between chromosomes 22 and 9. The two chromosomes exchange their terminal regions, which leads to a characteristic alteration in the size of chromosome 9.

B. At the breakpoint of this translocation, a new fusion protein, the BCR-ABL fusion, is generated.

C. The BCR-ABL fusion protein is a constitutively active kinase that phosphorylates multiple signal-transducing proteins.

D. If this translocation occurs in a hematopoietic cell in the bone marrow, the activity of the chimeric BCR-ABL oncogene dephosphorylate proteins thereby activating many intracellular signal-transducing proteins.

Which of the following statements are incorrect?

#Question id: 2858

#Unit 2. Cellular Organization

When lactose enters the cell, it is converted to allolactose. It is allolactose (rather than lactose itself) that controls the Lac repressor. Paradoxically, the conversion of lactose to allolactose is catalyzed by b-galactosidase, itself encoded by one of the lac genes. How is this possible? Which statement is incorrect according lac genes expressions?

#Question id: 2859

#Unit 2. Cellular Organization

NtrC controls expression of genes involved in nitrogen metabolism by inducing a conformational change in a pre-bound RNA polymerase, triggering transition to the open complex.

I. Under low nitrogen level condition, NtrC is phosphorylated by a kinase, NtrB,

II. NtrC (bound to its sites upstream) interacts directly with s54. This requires that the DNA between the activator binding sites and the promoter form a loop to accommodate the interaction

III. Active NtrC binds four sites located approximately 150 bp upstream of the glnA gene.

IV. NtrC itself has an ATPase activity which provides the energy needed to induce a conformational change in polymerase.

Correct series of Activation by NtrC is;

#Question id: 2860

#Unit 2. Cellular Organization

 Lactose metabolism in E. coli is carried out by two enzymes, with possible involvement by a third. The genes for all three enzymes are clustered together and transcribed together from one promoter, yielding a polycistronic message. These three genes, linked in function, are therefore also linked in expression. They are turned off and on together.

#Question id: 2861

#Unit 2. Cellular Organization

What is the result of regulatory mutation in given lac operon in merodiploids

#Question id: 2862

#Unit 2. Cellular Organization

What is the result of regulatory mutation in given lac operon in merodiploids,

#Question id: 2863

#Unit 2. Cellular Organization

The promoter of the araBAD operon from E. coli is activated in the presence of arabinose and the absence of glucose and directs expression of genes encoding enzymes required for arabinose metabolism. Unlike the cases of lac and gal genes, where a repressor and an activator work together, here two activators work together: AraC and CAP