1. Chromosomes are thick thread-like structures which appear in the nucleus during:
Answer: B. cell division
Biology Class 11 Unit 13: Chromosome and DNA MCQs
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2. In an interphase cell the chromosomes appear as a fine network called:
Answer: B. chromatin
3. A chromosome consists of two strands called:
Answer: B. chromatids
4. The two chromatids are attached at the:
Answer: C. centromere (primary constriction)
5. The secondary constriction which gives rise to the nucleolus is the:
Answer: C. nucleolar organizer
6. The knob-like terminal region beyond the secondary constriction is the:
Answer: C. satellite
7. The terminal ends of chromosomes are called:
Answer: C. telomeres
8. Telomeres prevent:
Answer: B. two chromosomes from attaching to each other at their ends
9. A chromosome with the centromere at the centre is:
Answer: D. metacentric
10. A chromosome with the centromere slightly away from the centre is:
Answer: B. submetacentric
11. A chromosome with the centromere near one end is:
Answer: C. acrocentric
12. A chromosome with the centromere at one end is:
Answer: D. telocentric
13. The chromosome is chemically made up of about:
Answer: B. 40 percent DNA and 60 percent protein
14. DNA in chromosomes is complexed with basic proteins called:
Answer: C. histones
15. Histones are rich in the basic amino acids:
Answer: B. arginine and lysine
16. A human chromosome contains DNA about:
Answer: B. 5 cm long with about 140 million nucleotides
17. A nucleosome consists of DNA wrapped around:
Answer: C. a core of eight histone molecules
18. Approximately every how many nucleotides of DNA wrap around a histone core?
Answer: C. 200
19. The DNA wraps around the histone core:
Answer: B. twice
20. Histone H1 acts as:
Answer: B. a linker which seals the DNA around the histone core
21. The nucleosome string is about how thick?
Answer: B. 10 nm
22. The chromatin fibre is about how thick?
Answer: B. 30 nm
23. The supercoil has a diameter of:
Answer: C. 300 nm
24. The chromatid is about how thick?
Answer: C. 700 nm
25. A chromosome (two chromatids) is about:
Answer: B. 1400 nm
26. The correct sequence of chromosome organization from DNA is:
Answer: B. nucleosome, chromatin fibre, supercoil, chromatid
27. Highly condensed and unexpressed chromatin is:
Answer: B. heterochromatin
28. Non-condensed chromatin in which genes are expressed is:
Answer: B. euchromatin
29. The question whether DNA or protein carries heredity was addressed by:
Answer: B. a series of investigators from the late 1920s over 30 years
30. Griffith worked with:
Answer: B. Streptococcus pneumoniae and mice
31. The S-type bacteria have a:
Answer: B. polysaccharide capsule and form smooth colonies
32. The R-type bacteria are:
Answer: B. non-virulent and rough colonies without capsule
33. When Griffith injected mice with live S-type, the mice:
Answer: B. died
34. When injected with heat-killed S-type plus live R-type, the mice:
Answer: B. died, and live S-type bacteria were found in the blood
35. The transfer of genetic material from one organism to another changing the genetic make-up of the recipient is called:
Answer: C. transformation
36. The transforming principle was identified as DNA in 1944 by:
Answer: B. Avery, MacLeod and McCarty
37. In Avery's experiment the extract treated with DNase:
Answer: B. did not cause transformation
38. In Avery's experiment the extract treated with protease:
Answer: B. still caused transformation, so protein is not the active factor
39. In Avery's experiment RNase treatment:
Answer: B. did not stop transformation, so RNA is not the active factor
40. The Hershey and Chase experiment was carried out in:
Answer: C. 1952
41. Hershey and Chase worked on:
Answer: B. bacteriophages and E. coli
42. They labelled phage DNA with:
Answer: B. 32P
43. They labelled phage protein with:
Answer: B. 35S
44. In the bacterial cells after infection they found:
Answer: B. 32P
45. In the medium after centrifugation they found:
Answer: B. 35S (phage protein coat)
46. Hershey and Chase proved that the hereditary material of phage is:
Answer: B. DNA
47. If you want to label amino acids but not DNA, you use the isotope:
Answer: B. 35S
48. DNA replication occurs only once during the:
Answer: B. S phase
49. The DNA molecule which is replicated is called the:
Answer: B. parent DNA
50. The three models of DNA replication are:
Answer: B. semi-conservative, conservative and dispersive
About Biology Class 11 Unit 13 MCQs (Federal Board)
These 228 Biology MCQs cover Class 11 Unit 13: Chromosome and DNA of the Federal Board (FBISE) HSSC-I (1st Year / Class 11) syllabus. They are SLO-based MCQs as per the new pattern for FBISE exams. Each question has four options and the correct answer is shown, so you can practise for the annual examination and find the topics you still need to revise. The questions are split over 5 pages of 50. Use the Print button to save this chapter as a PDF.