Following statements are regarding to the phosphoinositide signaling pathway.

A. Many RTKs and cytokine receptors can initiate the IP3/ DAG signaling pathway by activating phospholipase Cβ (PLCβ), a different PLC isoform.

B. Activated RTKs and cytokine receptors also can initiate another phosphoinositide pathway by binding a PI-3 kinase, thereby allowing the enzyme access to its membrane-bound phosphoinositide substrates, which then become phosphorylated at the 3 position.

C. Protein kinase B (PKB) becomes partially activated by binding to PI 3-phosphates with its PH domain.

D. Full activation of PKB requires phosphorylation by the kinase PDK1, which is also recruited to the membrane by binding to PI 3-kinase, and by a second kinase, PDK2.

Which of the following combination is incorrect?

#Question id: 2917

#Unit 2. Cellular Organization

With respect to the interconversion between open and condensed chromatin shown below: Which of the directions (i) or (ii) would you anticipate would be the consequence of the following types of chromatin modification?

#Question id: 2918

#Unit 2. Cellular Organization

Some DNA sequences in our cells have high frequencies of methylated cytosines (hypermethylation); some others have a low frequency of methylated cytosines (hypomethylation). Which of the two methylation states best describes the kind of sequences listed below? 

 I. Satellite DNA in pericentromeric heterochromatin

II. Promoters 

III. Dispersed transposon repeats

IV. CpG islands 

V. Enhancers

#Question id: 2919

#Unit 2. Cellular Organization

Topoisomerases play the essential role of unlinking the DNA molecules to allow them to separate into the two daughter cells for cell division. Which of the following statements regarding the mechanism of topoisomerases is INCORRECT?

#Question id: 2920

#Unit 2. Cellular Organization

Which of the following statements is INCORRECT with respect to the organization and content of the human genome?

#Question id: 2921

#Unit 2. Cellular Organization

During which stage of the cell cycle is the chromosome content of a mammalian liver cell 1n?

#Question id: 2922

#Unit 2. Cellular Organization

Human genes/proteins that regulate the cell cycle are most easily isolated by: