Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 3882
TLS Online TPP Program

#Question id: 4095

Many eukaryotic genes contain a large number of exons. Correct splicing of such genes requires that neighboring exons be ligated to one another; if they are not, exons will be left out. One early proposal suggested that the splicing machinery bound to a splice site at one end of an intron and scanned through the intron to find the splice site at the other end. Such a scanning mechanism would guarantee that an exon was never skipped. This hypothesis was tested with one minigene with a duplicated 3ʹ splice site. Find diagram of the products you expect from minigene if the splicing machinery binds to a 3ʹ splice site and scans toward a 5ʹ splice site.

#Unit 3. Fundamental Processes

  1. A & B

  2. B & C 

  3. B only 

  4. D only

More Questions
TLS Online TPP Program

#Question id: 73

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the Variation of Reaction Spontaneity (Sign of ΔG) given in Column I with the Signs of ΔH and ΔS given in column II.

COLUMN I

COLUMN II

 

 

 

  ΔH

ΔS

ΔG = ΔH – TΔS

1.

−

+

a. The reaction is both enthalpically and entropically opposed. It is nonspontaneous (endergonic) at all temperatures.

2.

 −

− 

b. The reaction is enthalpically opposed (endothermic) but entropically favored. It is spontaneous only at temperatures above T = ΔH/ΔS.

3.

+

+

c. The reaction is enthalpically favored but entropically opposed. It is spontaneous only at temperatures below T = ΔH/ΔS.

4.

+

−

d. The reaction is both enthalpically favored (exothermic) and entropically favored. It is spontaneous (exergonic) at all temperatures.

TLS Online TPP Program

#Question id: 73

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the Variation of Reaction Spontaneity (Sign of ΔG) given in Column I with the Signs of ΔH and ΔS given in column II.

COLUMN I

COLUMN II

 

 

 

  ΔH

ΔS

ΔG = ΔH – TΔS

1.

−

+

a. The reaction is both enthalpically and entropically opposed. It is nonspontaneous (endergonic) at all temperatures.

2.

 −

− 

b. The reaction is enthalpically opposed (endothermic) but entropically favored. It is spontaneous only at temperatures above T = ΔH/ΔS.

3.

+

+

c. The reaction is enthalpically favored but entropically opposed. It is spontaneous only at temperatures below T = ΔH/ΔS.

4.

+

−

d. The reaction is both enthalpically favored (exothermic) and entropically favored. It is spontaneous (exergonic) at all temperatures.

TLS Online TPP Program

#Question id: 74

#Unit 1. Molecules and their Interaction Relevant to Biology

The enthalpy and entropy of the initial and final states of a reacting system are shown in the table. Calculate the change in free energy for the reaction when the temperature is 4°C.
TLS Online TPP Program

#Question id: 75

#Unit 1. Molecules and their Interaction Relevant to Biology

The experimental approach taken in current biological investigations presumes that ________.
TLS Online TPP Program

#Question id: 76

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following illustrations is not a structural isomer of an organic compound with the molecular formula C6H14? For clarity, only the carbon skeletons are shown; hydrogen atoms that would be attached to the carbons have been omitted.
TLS Online TPP Program

#Question id: 77

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the pairs of molecular structures shown depict enantiomers (enantiomeric forms) of the same molecule?