Practice Questions

  1. Home
  2. Free Resources
  3. Practice Questions
  4. 2873
TLS Online TPP Program

#Question id: 2898

The human genome is composed of many different types of DNA sequences, the majority of which do not encode proteins. From the following distribution and amount of each of the various types of sequences determine which of these is CORRECTLY expressed?

#Unit 2. Cellular Organization

  1. More than 60% of the human genome is composed of intergenic sequences, and much of this DNA has no known function. About one-quarter of the intergenic DNA is repeated.

  2. Pseudogenes arise from the action of an enzyme called reverse transcriptase. This enzyme copies RNA into double-stranded DNA (referred to as copy DNA or cDNA).

  3. Microsatellite DNA is composed of very short (13 bp), tandemly repeated sequences. The most common microsatellite sequences are dinucleotide repeats (e.g., GAGAGAGAGAGAGAGA).

  4. Transposable elements are sequences that can “move” from one place in the genome to another and they now comprise 60% of the human genome due to their successful rate of propagation.

More Questions
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.
TLS Online TPP Program

#Question id: 30108

#Unit 1. Molecules and their Interaction Relevant to Biology

Aspartate plays a role in all of the following EXCEPT: