Biochemistry-I (BIO202)

1. Compounds that generate nitrous acid (such as nitrites, nitrates, and nitrosamines) change DNA molecules by:

   1. Breakage of phosphodiester bonds
   2. Deamination of bases
   3. Depurination
   4. Formation of thymine dimers

2. The DNA wrapped around the nucleosome core is continuous and joins one nucleosome core to the next -the linker DNA
   this 50 bp DNA is complexed with the fifth type of histone. ________

   1. H1
   2. H2A, H2B
   3. H3
   4. H4

3. Nucleotides also serve as carriers of activated intermediates in the synthesis of ________.

   1. Carbohydrates
   2. Lipids
   3. Proteins
   4. All of the given

4. Certain anticancer drugs, exert their cytotoxic effect by intercalating into
   the ________ groove of the DNA double helix, thus interfering with RNA and DNA synthesis

   1. narrow
   2. major
   3. phosphate backbone
   4. bases

5. The phosphodiester bonds that link adjacent nucleotides in both RNA and DNA:

   1. always link A with T and G with C.
   2. are susceptible to alkaline hydrolysis
   3. form between the planar rings of adjacent bases.
   4. join the 3' hydroxyl of one nucleotide to the 5'hydroxyl of the next.

6. When linked to vitamins nucleotides are structural components of several essential coenzymes, for example,

   1. coenzyme A
   2. coenzyme B
   3. coenzyme C
   4. coenzyme D

7. Chromatin is composed of

   1. nucleic acids and protein
   2. nucleic acids only
   3. proteins only
   4. None of the given

8. Nucleic acids are a polymer of nucleotide monomeric units. Each nucleotide consists of

   1. base-.sugar.-OH
   2. sugar.-phosphate
   3. base-.sugar.-phosphate
   4. sugar.-OH

9. Nucleoside contains

   1. base-sugar
   2. base-phosphate
   3. base-sugar-phosphate
   4. sugar-phosphate

10. A DNA segment contains 100 Adenine and 100 cytosines, how many nucleotides are present in the segment?

    1. 50
    2. 100
    3. 200
    4. 400

11. DNA that is not copied during the synthesis of mRNA is also called as

    1. Non Template
    2. coding strand
    3. mRNA-like strand
    4. All of the given

12. In living cells, nucleotides and their derivatives can serve as:

    1. carries of metabolic energy.
    2. enzyme cofactors.
    3. intracellular signals.
    4. All of the given

13. The sugar molecule present in nucleotide is

    1. Triose
    2. Tetrose
    3. Pentose
    4. Hexose

14. Nucleosomes can be packed more tightly to form a polynucleosome also called a nucleofilament or a ________nm fiber.

    1. 10
    2. 30
    3. 50
    4. 100

15. Under appropriate conditions DNA will form a hybrid with a complementary ________.

    1. DNA
    2. RNA
    3. Both DNA and RNA
    4. None of the given

16. Around structural core of the nucleosome, a segment of the DNA double helix is wound nearly twice-approximately ________.

    1. 100bp
    2. 120bp
    3. 140bp
    4. 160bp

17. These ________ bonds, plus the van der Waals and hydrophobic interactions between the adjacent stacked bases, stabilize the structure of the double helix.

    1. phosphodiester
    2. nitrogen
    3. hydrogen
    4. None of the given

18. Purine base found in RNA is

    1. Cytosine
    2. Thymine
    3. Guanine
    4. Uracil

19. Adenosine 3'-phosphate-5'-phosphosulfate is the ________ donor.

    1. Sulfate
    2. Phosphate
    3. Adenosine
    4. None of the given

20. There are ________ classes of histones

    1. 3
    2. 5
    3. 7
    4. 9

21. Z-DNA have a

    1. Zig-Zag apperarance
    2. Double helical nature
    3. uracil base
    4. single stranded nature

22. DNA model was presented by Watson and Crick in ________.

    1. 1951
    2. 1953
    3. 1955
    4. 1957

23. The difference between thymine and uracil is:

    1. one methylene group on the pyrimidine ring
    2. one methyl group on the pyrinidine ring.
    3. one hydroxyl group on the ribose ring.
    4. one amine group on the pyrimidine ring.

24. Disruption of DNA can occur in the laboratory with alteration in

    1. PH
    2. salt concentration
    3. heated above 80°C
    4. All of the given

25. A phosphodiester bond is present in

    1. Nucleic acids in a nucleotide
    2. Monosaccharides in a polysaccharide
    3. Amino acids in a polypeptide
    4. Fatty acids in a diglyceride

26. When DNA is heated, the temperature at which ________ of the helical structure is lost is defined as the melting temperature.

    1. one half
    2. two half
    3. three half
    4. complete

27. The "energy carrier" ATP is an example of a(n):

    1. deoxyribonucleoside triphosphate
    2. di-nucleotide
    3. ribonucleotide
    4. ribonucleoside triphosphate

28. S-adenosylmethionine is a ________ group donor.

    1. Methyl
    2. Phosphate
    3. Adenosine
    4. Sulfate

29. ATP is a

    1. nucleoside
    2. nucleotide
    3. vitamin
    4. nucleic acid

30. The complex folding of large chromosomes within eukaryotic chromatin and bacterial nucleoids is generally considered ________.

    1. primary structure
    2. secondary structure
    3. tertiary structure
    4. All of the given

31. DNA replication is

    1. Conservative
    2. Non-conservative
    3. Semi-conservative
    4. None of the given

32. higher GC base pairs increases Tm, because, with three hydrogen bonds, require ________ heat energy to dissociate than AT base pairs.

    1. less
    2. more
    3. equal
    4. None of the given

33. single-stranded DNA has a ________ relative absorbance at 260nm wavelength than does double-stranded DNA.

    1. lower
    2. higher
    3. equal
    4. None of the given

34. The DNA oligonucleotide abbreviated pATCGAC:

    1. has seven phosphate groups.
    2. has a hydroxyl at its 3' end.
    3. has a phosphate on its 3' end.
    4. has an A at its 3' end.

35. RNA duplexes are ________ stable than DNA duplexes.

    1. more
    2. less
    3. equal
    4. None of the given

36. Which one of the following is true of the pentoses found in nucleic acids?

    1. C-5 and C-1 of the pentose are joined to phosphate groups.
    2. The bond that joins nitrogenous bases to pentoses is an O-glycosidic bond.
    3. The pentoses are always in the β-furanose forms.
    4. The straight-chain and ring forms undergo constant interconversion.

37. Which one is example of coenzymes

    1. FAD
    2. NAD+
    3. NADP+
    4. All of the given

38. Separation of the two strands of the double helix when ________ bonds between the paired bases are disrupted.

    1. phosphodiester
    2. hydrogen
    3. glycosilic bond
    4. None of the given

39. In a double-stranded nucleic acid, cytosine typically base-pairs with:

    1. Adenosine
    2. Guanine
    3. Inosine
    4. Thymine

40. A short length of DNA molecule has 80 thymine and 80 guanine bases. The total number of nucleotide in the DNA fragment is

    1. 160
    2. 40
    3. 320
    4. 640

41. The Tm of DNA is influenced by

    1. higher the content of GC base pairs
    2. base composition of the DNA
    3. salt concentration of the solution
    4. All of the given

42. Which of the following is a palindromic sequence?

    1. AGGTCC
       TCCAGG
    2. CCTTCC
       GCAAGG
    3. GAATCC
       CTTAGG
    4. GGATCC
       CCTAGG

43. The ________ strand is called Template strand while

    1. 5'-3
    2. 3'-5
    3. 3'-3
    4. 5'-5

44. Nucleotides are composed of

    1. A nitrogenous base (purine or pyrimidine)
    2. A pentose monosaccharide
    3. One, two, or three phosphate groups
    4. All of the given

45. Eukaryotic DNA is associated with tightly bound basic ________, called histones.

    1. lipid
    2. proteins
    3. carbohydrates
    4. nucleic acid

46. Any regular, stable structure taken up by some or all of the nucleotides in a nucleic acid can be referred to as

    1. primary structure
    2. secondary structure
    3. tertiary structure
    4. All of the given

47. According to Chargaff's Rules
    which one is not correct

    1. adenine equals the amount of thymine.
    2. guanine equals the amount of cytosine
    3. total amount of purines equals the total amount of pyrimidines
    4. guanine equals the amount of thymine

48. Find the correct statement about phosphodiester linkage between adjacent nucleotides in nucleic acids

    1. 3'-phosphate of one nucleotide joins the 3'-hydroxyl of the next nucleotide
    2. 3'-phosphate of one nucleotide joins the 5'-hydroxyl of the next nucleotide
    3. 5'-phosphate of one nucleotide joins the 5'-hydroxyl of the next nucleotide
    4. 5'-phosphate of one nucleotide joins the 3'-hydroxyl of the next nucleotide

49. histones are ________ charged

    1. positively
    2. negatively
    3. neutral
    4. None of the given

Select a course code for Objective Questions:

ACC311 ACC501 BIF101 BIF401 BIF501 BIO101 BIO201 BIO202 BIO203 BIO204 BIO301 BIO302 BIO303 BIO401 BIO503 BNK603 BT101 BT201 BT301 BT302 BT401 BT402 BT403 BT404 BT405 BT406 BT501 BT504 BT505 BT604 CHE201 CHE301 CS001 CS101 CS201 CS202 CS204 CS301 CS302 CS304 CS311 CS401 CS402 CS403 CS408 CS501 CS502 CS504 CS506 CS508 CS601 CS602 CS604 CS605 CS607 CS609 CS610 CS614 CS707 CS710 ECO401 ECO402 ECO403 ECO404 EDU302 EDU401 EDU402 EDU501 EDU601 ENG101 ENG201 ENG301 ENG501 FIN611 FIN624 FIN625 ISL201 IT430 MCM101 MCM301 MGMT623 MGT101 MGT211 MGT301 MGT401 MGT402 MGT501 MGT502 MGT503 MGT510 MGT601 MGT603 MKT501 MKT610 MKT630 MTH101 MTH202 MTH302 MTH501 MTH601 MTH634 PAK301 PHY101 PHY301 PSY101 PSY403 PSY502 PSY512 SOC101 SOC301 SOC401 STA301 STA630 STA641 ZOO102 ZOO401 ZOO501 ZOO502 ZOO503 ZOO504 ZOO505 ZOO506 ZOO510 ZOO630

Select a course code for Subjective Questions:

ACC311 CS001 CS101 CS201 CS301 CS607 CS701 CS702 CS703 CS704 CS707 CS708 CS710 CS711 CS718 CS721 CS724 ECO401 ECO403 ENG101 ENG301 MGT703 MTH501 STA301