Molecular Basis of Inheritance
1. 5-methyl uracil is 10. In DNA segment of six coils, 22 bp are linked by two
(A) Another name of thymine hydrogen bonds. How many cytosine bases would be
(B) A purine base present?
(C) A double ring structure (A) 22
(D) Both (A) and (C) (B) 38
2. A + G = C + T is applicable to (C) 44
(A) rRNA (B) tRNA (D) 76
(C) mRNA (D) DNA 11. Choose correct statements regarding DNA is genetic
3. 5’ end of a polynucleotide chain contains material
(A) Hydroxyl group 1. Its stability
(B) Ethyl group 2. Its ability to replicate
(C) Carboxyl group 3. Its ability to mutate
(D) Phosphate group 4. Its ability to express itself
4. The two strands of DNA are held together by (A) 1 and 2 (B) 1, 3 and 4
(A) Peptide bonds (C) 3 and 4 (D) 1, 2, 3 and 4
(B) Phosphodiester bonds 12. Anti-parallel strands of a DNA molecule means that
(C) Hydrogen bonds (A) One strand turns clockwise.
(D) S—S bonds (B) One strand turns anti-clockwise.
5. Variable part of DNA molecule is (C) The phosphate group of two DNA strands, at
(A) Phosphate (B) Sugar their ends, share the same position
(C) Nitrogen base (D) Both (B) and (C) (D) The phosphate group at the start of two DNA
6. Nucleotide pairs present in one turn of DNA helix are strands are in opposite position (pole).
(A) 20 (B) 8 13. Genetic information in a DNA molecule are coded in
(C) 10 (D) 9 the
7. Who proposed central dogma? (A) Number of bases.
(A) Watson and Crick (B) Beadle and Tatum (B) Sequence of nucleotides.
(C) Klug (D) Crick (C) Length of DNA.
8. Information flow or central dogma of modern biology is (D) Number of nucleosides.
(A) RNA—Proteins—DNA 14. If an isolated strain of DNA is kept at 82-90°C, then
(B) DNA—Proteins—RNA (A) It changes into RNA.
(C) RNA—DNA—Proteins (B) It divides into 1 million pieces.
(D) DNA—RNA—Proteins (C) No effect is observed
9. Number of hydrogen bonds between A and T of DNA (D) Separation of two strands of DNA molecule.
is 15. Nucleotide arrangement in DNA can be seen by?
(A) 4 (A) X-ray crystallography.
(B) 3 (B) Electron microscope.
(C) 2 (C) Ultracentrifuge.
(D) 1 (D) Light microscope.
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, 16. The association of histone H1 with a nucleosome 25. Griffith’s experiments showing the transformation of
indicates R strain pneumococcus bacteria to S strain
(A) Transcription is occurring. pneumococcus bacteria in the presence of heat-killed
(B) DNA replication is occurring. S strain bacteria gave evidence that
(C) The DNA is condensed into a chromatin fibre. (A) An external factor was affecting the R strain
(D) The DNA double helix is exposed. bacteria
17. How many nucleosomes are present in human cell (B) DNA was definitely the transforming factor.
(A) 3.3×107 nucleosome (C) S strain bacteria could be reactivated after heat
(B) 1.1×107 nucleosome killing
(C) 6.6×107 nucleosome (D) All of the above
(D) Indefinite 26. Biochemical nature of genetic material was not
18. Histone proteins are rich in defined from
(A) Histidine and arginine (A) Transforming principle
(B) Histidine and lysine (B) Hershey and Chase experiment
(C) Histidine, arginine and lysine (C) Avery, Macleod and McCarty
(D) Arginine and lysine (D) None of the above
19. Find out the number of nucleosomes present in a 27. Which of the following heavy/radioisotopes is not
human cell. suitable for DNA labelling based studies?
3 32
(A) 16.50 million (A) H (B) P
15 35
(B) 16.50 billion (C) N (D) S
(C) 33 million 28. Bacteriophage with radioactivity both in DNA and
(D) 200 million protein infects a bacterium. Bacterium becomes
20. The ‘beads on string’ structure which is seen under radioactive. Radioactivity occurs in
EM are (A) Protein (B) DNA
(A) Histone octamer (C) All parts (D) Both (A) and (B)
(B) Nucleosome 29. Escherichia coli with completely radioactive DNA was
(C) Chromatin allowed to replicate in non-radioactive medium for
(D) Chromatin fibres two generations. Percentage of bacteria with
radioactive DNA is
21. DNA is acidic due to
(A) 100% (B) 50%
(A) Sugar (B) Purine
(C) 25% (D) 12.5
(C) Phosphate group (D) Pyrimidine
30. Genetic RNA is
22. Chromatin is chemically made of
(A) Genetic material of RNA viruses
(A) Nucleic acid, histone and non-histone proteins
(B) RNA that carries genetic message
(B) Nucleic acid and histone proteins only
(C) RNA that helps gene regulation in lac operon
(C) Nucleic acid and non-histone proteins only
(D) RNA present in mitochondria
(D) Nucleic acid only
31. Select the correct statements from the following given
23. Stability as one of the properties of genetic material below
was very evident in (I) rRNA provides the template for synthesis of
(A) Griffith’s transforming principle protein.
(B) Hershey and Chase experiment (II) t-RNA bring amino acids and reads the genetic
(C) Meselson & Stahl’s centrifugation technique code.
(D) Taylor’s experiment (III) RNA polymerase bind to promoter and initiates
transcription
24. A bacterium grown over medium having radioactive
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(IV) A segment of DNA coding for polypeptide is
S incorporates radioactivity in called intron.
(A) Carbohydrates (B) Proteins (A) I and III (B) I and II
(C) DNA (D) RNA (C) I, II and III (D) II and III
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