TLS Online TPP Program

#Question id: 15844


You have isolated two temperature-sensitive mutations in phage l that you suspect may be in the same gene. These phage mutants are called ts-1 and ts-2. Each mutant will form plaques at 35˚C but not at 42˚C. You cross ts-1 to ts-2 phage by coinfecting E. coli at the permissive temperature of 35˚C. When the resulting phage lysate is plated at 35˚C you count 10,000 plaques per ml of phage lysate, but when the same phage lysate is plated at 42˚C, there are only 80 plaques per ml.  
If the total size of the phage is 5 x 104 bp and the total genetic map length of the phage is 100 m.u., about how far apart are the mutations in base pairs?

#Unit 8. Inheritance Biology
  1. 500 bp
  2. 300 bp
  3. 800 bp
  4. 400 bp
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TLS Online TPP Program

#Question id: 68

#Unit 1. Molecules and their Interaction Relevant to Biology

Match the following functional groups given in column I with their respective representatives given in column II.

COLUMN I               COLUMN II

1. Anhydride               a. RCOOR

2. Ether                       b. ROCOCH3

3. Acetyl                     c. ROR

4. Amido                     d. RCOOCOR

5. Ester                        e. RCONH2

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: 674

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline is not often found in a-helices of proteins because it

TLS Online TPP Program

#Question id: 1520

#Unit 1. Molecules and their Interaction Relevant to Biology

Following statements are regarding to enzymatic processing of benzo(a)pyrene to a more potent mutagen and carcinogen.

A. Liver enzymes, particularly P-450 enzymes, modify benzo(a)pyrene in a series of reactions, producing 7,8-diol-9,10-epoxide, a highly potent mutagenic species that reacts with DNA primarily at the N2 atom of a guanine base.

B. The adduct, (+)-trans-anti-B(a)P-N2-dG, causes polymerase to insert an A rather than a C opposite the modified G base. Next time the DNA is replicated, a T will be inserted opposite the A, and the mutation will be complete.

C. Potent mutagen majorly causes conversion of guanine (G) to thymine (T) bases, a transition mutation.

D. When this potent mutagen applied to cultured bronchial epithelial cells, activated benzo(a)pyrene induces many mutations, including activating mutations at codons 175, 248, and 273 of the p53 gene.

Which of the following statements are correct?

TLS Online TPP Program

#Question id: 835

#Unit 1. Molecules and their Interaction Relevant to Biology

The minor clefts and gullies on the sides of the funnel that will be false energy minima, it represents,

TLS Online TPP Program

#Question id: 837

#Unit 1. Molecules and their Interaction Relevant to Biology

Increasing order of free energy in unfolded to folded conformation of the proteins, the correct order is,