Test Your Knowledge - Free MCQ PRACTICE
by Saksham Chaudhry : 23-B Model Town, Fatehabad 125050 M: 9810570740, 9810571993
A fresh set of 20 random questions is generated every time you open this page and every time you refresh it.
For each of the following multiple choice questions, choose the most appropriate answer :

1. Which of the following is not part of the lac operon?
A. I
B. O
C. P
D. none of these

2. The tertiary structure of yeast tRNA
A. involves extensive base stacking interactions
B. resembles the 3-dimensional structure of other tRNAs
C. is maintained mostly by non-Watson-Crick base pairing
D. all of the above

3. The first protein complex to bind to the TATA box is
A. transcription factor IIA
B. transcription factor IIB
C. transcription factor IID
D. all of these

4. Enzyme defective in Tyrosinemia Type I is
A. Fumaryl acetoacetate hydrolase
B. Tyrosine amino transferase
C. Para hydroxyl phenyl pyruvate hydroxylase
D. Para hydroxyl phenyl pyruvic acid oxidase

5. Which of the following indicates that the pK of an acid is numerically equal to the pH of the solution when the molar concentration of the acid and its conjugate base are equal?
A. Michaelis-Menten equation
B. Haldanes equation
C. Henderson-Hasselbalch equation
D. Hardy-Windberg law

6. When the amino acid alanine (R-group is CH3) is added to a solution with a pH of 7.3, alanine becomes
A. a cation
B. nonpolar
C. a zwitterions
D. an isotope

7. Why is the TCA cycle the central pathway of metabolism of the cell?
A. It occurs in the center of the cell
B. Its intermediates are commonly used by other metabolic reactions
C. All other metabolic pathways depend upon it
D. None of the above

8. In Phenylketonuria, the first line therapy is:
A. Replacement of the defective enzyme
B. Replacement of the deficient product
C. Limiting the substrate for deficient enzyme
D. Giving the missing amino acid by diet

9. Lack of reaction to our own human leukocyte antigens (HLAs) is known as?
A. autoimmunity
B. complement system
C. clonal selection
D. tolerance

10. For a molecule to absorb IR, why must the molecule's vibrations cause fluctuations in the dipole moment of the molecule?
A. Because a change in dipole moment lowers the energy required for electronic transitions
B. Because for absorption to occur, the radiation must interact with the electric field caused by changing dipole moment
C. Because fluctuations in the dipole moment allow the molecule to deform by bending and stretching
D. All of the above

11. If a person is vaccinated against a disease sometime in the past, which of the following is currently in your body?
A. The disease organism itself and antigens for the disease organism
B. A very high level of antibodies against the disease antigens
C. Memory B lymphocytes for the antigen of this disease organism
D. All of the above

12. The genetic material of retroviruses such as HIV is
C. protein
D. all of these

13. Sex lethal (sxl) in Drosophila is transcribed when
A. the X autosome balance is less than 0.5
B. the X autosome balance is 1 or greater
C. the X autosome balance equals 0.5
D. none of the above

14. The molecular formula for glycine is C2H5O2N. What would be the molecular formula for a linear oligomer made by linking ten glycine molecules together by condensation synthesis?
A. C20H50O20N10
B. C20H32O11N10
C. C20H40O10N10
D. C20H68O29N10

15. The peptide, Val-Lys-Glu-Met-Ser-Trp-Arg-Ala, was digested with cyanogen bromide (CNBr) to produce:
A. Val-Lys + Glu-Met-Ser + Trp-Arg-Ala
B. Val-Lys-Glu-Met-Ser-Trp + Arg-Ala
C. Val-Lys-Glu-Met + Ser-Trp-Arg-Ala
D. Val-Lys-Glu + Met-Ser-Trp-Arg-Ala

16. Why must the radiation source for fluorescence spectrometry be more powerful than for absorption spectroscopy?
A. Because the magnitude of the output signal is proportional to the power of the incident radiation
B. Because the sample won't fluoresce if the incident radiation is of low power
C. To allow for scattering by the sample
D. None of the above

17. Nucleoside is a pyrimidine or purine base
A. covalently bonded to a sugar
B. ionically bonded to a sugar
C. hydrogen bonded to a sugar
D. none of the above

18. Why does the glycolytic pathway continue in the direction of glucose catabolism?
A. There are essentially three irreversible reactions that act as the driving force for the pathway
B. High levels of ATP keep the pathway going in a forward direction
C. The enzymes of glycolysis only function in one direction
D. Glycolysis occurs in either direction

19. Nitisinone can be used in
A. Alkaptonuria
B. Hereditary tyrosinemia type I
C. Both A and B
D. None

20. Why is it advantageous to record many FID signals from the same sample and then add them together?
A. To ensure that all target nuclei in the sample have been excited
B. To remove inaccuracies caused by fluctuations in the applied magnetic field
C. To increase sensitivity
D. None of the above

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