Following statements are regarding to the early development of C.elegans (expression of PIE-1):

A. Segregation of PIE-1 determinant into the P1 blastomere at the 2-cell stage

B. The sperm centrosome activates the presence of the PAR-3/PAR-6 complex in the posterior of the egg

C. PIE-1 is degraded in the resulting anterior AB cell, it is preserved in the posterior P1 cell

D. PIE-1 is degraded in the resulting posterior P1 cell, it is preserved in the anterior AB cell

Which of the following combination is incorrect?

TLS Online TPP Program

#Question id: 30102

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following would NOT be expected to contribute to hyperuricemia (gout)?

TLS Online TPP Program

#Question id: 30103

#Unit 1. Molecules and their Interaction Relevant to Biology

Direct sources of purine ring atoms in the de novo synthesis of IMP include:

1. glutamine.

2. a component of the tetrahydrofolate one-carbon pool.

3. aspartate.

4. glycine.

TLS Online TPP Program

#Question id: 30104

#Unit 1. Molecules and their Interaction Relevant to Biology

A nucleoside phosphorylase:

1. cleaves a nucleoside with the production of ribose 1-phosphate.

2. is necessary for the major salvage pathway for pyrimidines.

3. is used in the degradation of purine nucleotides.

4. is responsible for the equilibration of nucleoside monophosphates and nucleoside diphosphate.

TLS Online TPP Program

#Question id: 30105

#Unit 1. Molecules and their Interaction Relevant to Biology

Methotrexate is an inhibitor of dihydrofolate reductase. Administration of methotrexate would inhibit:

1. de novo synthesis of UMP.

2. conversion of dUMP to dTMP.

3. conversion of IMP to GMP.

4. de novo synthesis of IMP

TLS Online TPP Program

#Question id: 30106

#Unit 1. Molecules and their Interaction Relevant to Biology

If a cell has an adequate supply of adenine nucleotides but requires more guanine nucleotides for protein synthesis:

1. Glutamine-PRPP amidotransferase will not be fully inhibited.

2. AMP will be a feedback inhibitor of the condensation of IMP with aspartate.

3. ATP will stimulate the production of GMP from IMP.

4. ATP will inhibit nucleoside diphosphate reductase.

TLS Online TPP Program

#Question id: 30107

#Unit 1. Molecules and their Interaction Relevant to Biology

Major controls of de novo AMP synthesis include:

1. allosteric inhibition by GMP.

2. allosteric inhibition by AMP.

3. availability of PRPP.

4. stimulation by GTP.