we examine how the deregulation of growth-promoting and growth-inhibiting signaling pathways contributes to tumorigenesis. Mutations-

A. A mutation that alters a single amino acid (valine to glutamine) in the transmembrane region of the HER2 receptor

B. A deletion that causes loss of the extracellular ligand-binding domain in the EGF receptor Results-

i. dimerization of the receptor, even in the absence of the normal EGF-related ligand, transforming it into the oncoprotein, a constitutively active kinase

ii. to constitutive activation of the kinase activity of the resulting oncoprotein

iii. no dimerization, even in the presence of the normal EGF-related ligand, repression of kinase activity

which of the following results are displayed after these mutations?

#Question id: 2987

#Unit 2. Cellular Organization

Following statements are regarding the goals of gap phases.

(i) to prepare for the next phase of the cell cycle.

(ii) to check that the previous phase of the cell cycle has been completed appropriately.

(iii) to inhibits CDKs activity.

(iv) to enhance servillance mechanisms.

Which of the following is correct?

#Question id: 2988

#Unit 2. Cellular Organization

Use the figure to answer the question below. 

If the cell whose nuclear material is shown in the figure continues toward completion of mitosis, which of the following events would occur next?

#Question id: 2989

#Unit 2. Cellular Organization

Use the figure to answer the question below.

In the figure, G1 is represented by which numbered part(s) of the cycle?

#Question id: 2990

#Unit 2. Cellular Organization

Mitotic CDK complexes are maintained in an inactive state through inhibitory phosphorylation of the CDK subunit. Two highly conserved tyrosine and threonine residues in mammalian CDKs are subject to regulated phosphorylation.

The following table enlists genes and phenotypes observed on mutation of these genes but not correctly matched. Which one of the following combinations is correctly matched ?

#Question id: 2991

#Unit 2. Cellular Organization

Early observations of a cultured cell line indicated that the cells did not exhibit either density-dependent inhibition or anchorage dependence. What do these observations suggest about this cell line?

#Question id: 2992

#Unit 2. Cellular Organization

DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. Which sample of DNA might be from a cell that stopped the process of cell division in G0 phase of the cell cycle prior to meiosis?