Lesson 4 – DNA packing in chromosome exam – Brihha Assessment Platform

1. Describe about the ultra structure of eukaryotic chromosome.

2. How will you separate different histone proteins present in the cell.

3. Describe the procedure to study the methylation pattern of
chromosome.

4. How will you check the size of the linker DNA?

5. Why it is difficult to study the chromosome at interphase stage?

6. If a free phosphate is found at the 5’ end of a DNA strand, what is
found at the other end of the same strand?

A hydroxyl group on the 5’ carbon of a deoxyribose sugar

A hydroxyl group on the 3’ carbon of a deoxyribose sugar.

A phosphate group on the 5’ carbon of a deoxyribose sugar

A phosphate group on the 3’ carbon of a deoxyribose sugar

7. In higher eukaryotes, the number of copies of the genes encoding
which of the following is the highest?

5S rRNA

18S rRNA

28S rRNA

23S rRNA

8. Which of the following statements regarding the structure of
chromosomal DNA is correct?

The two strands of DNA align in parallel directions

Basepairs in DNA are comprised of either two purine or two pyrimidine nucleotides.

The structure consists of double-stranded DNA wrapped around histones.

The double-stranded helix is held together only by hydrogen bonds.

9. Double-helical DNA has major and minor grooves because:

The A:T and G:C base pairs have different dimensions

Purines, being larger, form the major groove while pyrimidines, being smaller, form the minor groove.

DNA-binding proteins twist the DNA into a specific shape.

The phosphoribose backbones of the two strands are not diametrically opposite.

10. Each clusters of rRNA genes is known as

Nucleolar organizer

Nucleosome

Both of these

None of these

11. The translated genes of genomes that encode proteins are referred
to as

Open Reading Frame

Introns

Codons

Pseudogenes

12. There are……………..types of histones in eukaryotic chromosomes

4

5

6

3

13. Which histone is not found in nucleosome

H1

H2A

H3

H4

14. Complementary base pairing is the result of

Hydrogen bonding

Covalent bonding

Ionic bonding

The fact that strands of DNA are unwound around each other in a double helix

15. Nucleosomes are ____nm in diameter

10

2

30

20

16. __________ are the most abundant proteins found in chromatin

Histone

Actin

Myosin

Nucleoplasmin

17. Solenoid is _____nm in diameter.

10

2

30

20

18. __________ are the acidic proteins found in chromatin

Histone

Actin

Myosin

Nucleoplasmin

19. What are the modification of histones found in eukaryotes

Acetylation

Methylation

Phosphorylation

All of the above

20. Exchange of non-homologous segments between chromosome is
termed as

Crossing over

Translocation

Synapsis

None of the above

21. H1 histone protein is rich in amino acid.

22. First order of chromosome folding is .

23. Several beads separated by linker DNA, present along with H1
histones is called .

24. Distance between two strands of a DNA double helix is nm

25. Histone core condenses the DNA for times.

26. Size of beads on a string is nm

27. Six to seven chromatosomes are condensed in a helical pattern to
form a .

28. are acidic proteins act as molecular chaperons and are
necessary for nucleosome assembly

29. Methylation of chromosome occurs in islands.

30. histone is having a repressive gene activity.

31. Histone proteins are positively charged.

True

False

32. N- and C-terminal histone tails extend out of the nucleosome.

True

False

33. Treatment of chromatin with trypsin or high salt buffer removes
histone H1.

True

False

34. H3 and H4 histones are rich in arginine amino acid.

True

False

35. Second order of chromatin folding produces 30 nm fibre.

True

False

36. During interphase chromatin are in form of 30 nm fibre.

True

False

37. Acetylation of histone increases gene activity.

True

False

38. Chromatin condensation increases with ionic strength.

True

False

39. Nucleosome model was proposed by Kornberg and Oudet.

True

False

40. . Histones play a predominant role as regulators of genetic activity.

True

False