The pH dependence of the rate of the RNase A reaction suggests the involvement of 

a. Two ionizable residues with pK values of 5.4 and 6.4

b. Single ionizable residue with pK values 7

c. Cytosine residue in active site

#Question id: 12552

#Unit 10. Ecological Principles

#Question id: 4659

#Unit 3. Fundamental Processes

Many bacterial responses are controlled by two component regulatory systems. What will happen at the high concentration of glutamine and at the low concentration of glutamine?

a) At high concentrations glutamine binds to a sensor domain of NtrB conformational change in the protein that inhibits its histidine kinase activity

b) NtrC phosphorylation takes place causes a conformational change in NtrC that unmasks the NtrC DNA-binding domain so that it can bind to the glnA enhancers

c) At the same time, the regulatory domain of NtrC blocks its DNA-binding domain from binding the glnA enhancers

d) At low concentrations of glutamine dissociates from the sensor domain in the NtrB protein, leading to activation of a histidine kinase transmitter domain

Which of the following given combination is correct?

#Question id: 15272

#Unit 13. Methods in Biology

#Question id: 3349

#Unit 11. Evolution and Behavior

Which of these evolutionary agents is most consistent at causing populations to become better suited to their environments over the course of generations?

#Question id: 21263

#Unit 12. Applied Biology