2nd Year Biology Chapter 20 Chromosomes and DNA Notes

biology 12th notes chapter 20

1. Which of the following is not termination or non-sense code?


2. Okazaki fragment is a


3. The strong evidence in support of chromosomal theory of inheritance was given by


4. Empty tRNA is present in


5. Genetic code is combination of


6. DNA was discovered in 1869 by


7. Which of the followings is absent in minimal medium?


8. This condition appears as a result of point mutation:


9. One gene encodes for one


10. RNA polymerase has subunit


11. Which of the followings helps the tRNA to attach on exposed mRNA code at A site


12. The synthesis of protein is called


13. Meselson and Stahl used radioactive isotope of


14. The base pair stack is apart


15. The model in which both strands break is


16. X-ray diffraction technique was used by


17. The binding of tRNA to ribosomal unit is controlled by


18. Which is incorrect about Watson and Crick model?


19. Sickle anemia is a


20. The strand which elongate towards replication fork is


21. The highly condensed portion of chromatin is called


22. The true replicating enzyme is


23. Repeating units of DNA are called


24. Transcription starts at


25. Number of hydrogen bonds formed between Guanine and Cytosine are


26. Transforming principle was formulated by


27. The base pairs in human genome are


28. The synthesis of RNA from DNA is


29. One of the given does not code for any amino acid?


30. The disease alkaptonuria was studied by


31. A central role for chromosomes in heredity was first suggested in 1900 by


32. Total number of genetic codes is


33. The diameter of DNA molecule is


34. Human cells contain how many different kinds of tRNA molecules:


35. The disease which causes mental retardation is


36. Basic structure of nucleic acid was determined by


37. The ultimate source of changes is


38. The ribosome moves in a direction of mRNA


39. The stop signal GC series of base pairs is the part of:


40. Number of chromosomes in mouse is


41. Central dogma is composed of


42. Okazaki fragments are synthesized by


43. Number of hydrogen bonds formed between Adenine and Thymine are


44. Experiments on bacteriophage were performed by


45. If the DNA of an human adult is lined up end to end, it will stretch nearly


46. Okazaki fragments are formed in lagging strand because


47. In bacteria the newly synthesized mRNA is released in


48. The code of arginine is


49. Sickle cell anemia is caused due to change of glutamic acid to


50. Each Okazaki fragment is synthesized by:


51. In eukaryotes, the numbers of nucleotides in Okazaki fragments are about


52. The amount of DNA in chromosomes is


53. DNA polymerase only adds nucleotides to the end:


54. The binding site is


55. If the alterations involve only one or a few base pairs-in the coding sequence they are called:


56. Which of the followings is a stop signal for transcription?


57. All of the following are non-sense codons except that of:


58. tRNA is synthesized by


59. Sequence of amino acids in insulin molecules were determined by


60. DNA was discovered in


61. X-ray diffraction analysis of DNA was performed by:


62. The strange result of T.H.Morgan was


63. A chromosome with equal length of its arms:


64. In 1953, F-Sanger described the complete sequence of Amino Acids of


65. The enzyme which attaches the fragments of DNA is


66. Meselson and Stahl found that the DNA collected immediately after transfer was dense because


67. Chromosomal part which uncoils, during inter phase is called:


68. Codes are present on


69. In the next generation of phage virus, the virus found radioactive were with


70. The transforming activity is destroyed due to


71. mRNA is synthesized by


72. The structure formed by super coiling of DNA is


73. The chromosome with centromere near the end of chromatids is


74. Nucleosome occurs at every:


75. The model in which both strands are preserved is


76. Sickle cell anemia was discovered by


77. DNA changes are called mutations and organisms that have these changes are called:


78. The number of chromosomes pairs in corn is:


79. Which of the following is mismatched for genetic code?


80. The sequence of nucleotides that determines the amino acid sequence of a protein is called


81. Chromosomes were first observed by


82. Which of the following does not come within central dogma?


83. The number of chromosomes in mouse is:


84. Tail of mRNA is


85. Double helical structure of DNA was proposed by


86. The karyotypes of a chromosomes are


87. Which of the following is incorrect observation of experiments by Avery and coworkers?


88. The number of chromosomes in some ferns is


89. The addition of one or a few bases is


90. The semi conservative model is


91. Walther Fleming discovered chromosomes in larva of


92. The opposite strand is called coding strand or sense strand in transcription because


93. RNA polymerase ll synthesize


94. Experiments on Neurosopora were performed by


95. The genetic code for alanine is


96. The substitution of one or more bases of DNA is called


97. The semi conservative model of DNA was proved by


98. Which one of the following is initiation codon?


99. The bead like structure present in the chromosome is


100. Which of these initiation codes?


101. Beadie and Tatum exposed Neurospora spores to:


102. A typical chromosome contain nucleotide about


103. Enzymes are responsible for assembly of 


104. The chromosome in which centromere is present near the centre of chromatids is


105. The strand which is transcribed during transcription is


106. First amino acid in the synthesis of protein is


107. Match homogenetisic acid with one of the followings


108. The movement of ribosome to next code is controlled by


109. The change of chromosomal number is


110. The model of DNA replication in which one strand is conserved and other is synthesized is


111. The site of ribosome where peptide bond is formed is


112. Coding strand is


113. The termination codes are recognized by


114. mRNA is synthesized by


115. The enzyme which plays a supporting role in DNA replication is


116. Chromosomal theory of inheritance suggests that


117. Number of histone protein molecules in single nucleosomes are


118. The strand which elongates towards the replication fork is


119. Genetic code for glycine is


120. Chromosomal theory of heredity was proposed by


121. The DNA polymerase adds how many nucleotides to the end?


122. The part of chromosome whose genes are expressed is called


123. Okazaki fragments are synthesize by


124. The objection on chromosomal theory of inheritance was


125. Change in gene position is


126. Genetic code for phenylalanine is


127. Cap in mRNA is


128. The length of Okazaki fragments is


129. The scientist who suggested that the information encoded within the DNA of chromosomes acts to specify particular enzymes waste


130. Anticodons are present on


131. Erwin Chargaff showed that the amount of guanine in DNA is always equal to:


132. In semi-conservative model the strands are separated and act as


133. Experiments on mice were performed by


134. Which of the following is not mutagen?


135. Minimal medium was prepared by


136. Number of chromosomes in Sugar cane is


137. Particular array of chromosomes that an individual possesses is called its: Karyotype


Short Questions

1. Compare replication, transcription and translation.
2. Define chromosomal theory of inheritance.
3. Define Conservative Replication of DNA?
4. Define karyotype. What is karyotype? What do you mean by karyotype? Give its significance.
5. Define nucleosome.
6. Define nucleotide and nucleoside.
7. Define one gene/one polypeptide hypothesis?
8. Define point mutation. State point mutation with examples. Define point mutations.Give one example.
9. Define replication or what is replication?
10. Define the chromosome theory of ingeritance?
11. Define transcription and how it is initiated? What is the function of RNA polymerase in transcription?
12. Differentiate among conservative, semi-conservative and dispersive replication of DNA.
13. Differentiate between heterochromatin and euchromatin?
14. Differentiate between leading and lagging strand.
15. Differentiate between rough and smooth type of bacteria.
16. Differentiate between sense and anti-sense strands of DNA.
17. Enlist different shapes of chromosome.
18. Explain karyotype?
19. Explain nucleosome?
20. Give the length of Okazaki fragment. What are Okazaki fragments?
21. Give the role and kinds of tRNA.
22. How DNA polymerase III can initiate synthesis of DNA?
23. How do the chromosomes differ from one another?
24. How do X and Y chromosomes of Drosophila differ with respect to eye colour gene?
25. How long DNA would stretch if the DNA in all of the cells of an adult human were lined up end to end?
26. How many nucleotides are contained in a typical human chromosome?
27. How many types of DNA polymerases are found, write down their names?
28. How much information is contained in one chromosomes?
29. How would you identify a metacentric chromosome?
30. Name the basic proteins in the chemical composition of chromosomes?
31. Name the kinds of nucleic acids?
32. Name the nitrogenous bases of the nucleotides of DNA?
33. What a typical chromosome is made up of ?
34. What are chromosomes?
35. What are different shapes of chromosomes?
36. What are different types of chromosomes depending upon location of centromere?
37. What are heteromatin?
38. What are mutagens? Give one example.
39. What are Okazaki fragments?
40. What are supercoils of DNA?
41. What are the chromosomes chemically composed of and in what percentage?
42. What are the components of a nucleotide of DNA according to P.A.Levene?
43. What are the contributions of P.A.Levene for determining the structure of DNA?
44. What are the main components of DNA?
45. What are the three major classes of RNA?
46. What are the units of the DNA molecule known as?
47. What does transformation mean in the life cycle of pneumonia bacteria?
48. What does X-Ray diffraction of DNA suggest?
49. What is a chromosome typically made of?
50. What is a sex linked trait?
51. What is alkaptonuria? What is phenylketonuria? Differentiate between alkaptonuria and phenylketonuria.
52. What is anticodon?
53. What is central dogma?
54. What is Dispersive Replication of DNA?
55. What is euchromatin?
56. What is Friedrick Miescher famous for?
57. What is genetic code? What are non-sense codons? Enlist non-sense codons and their function.
58. What is heterochromatin? What is euchromatin? Differentiate between heterochromatin and euchromatin.
59. What is initiation codon?
60. What is Karl Correns famous for?
61. What is Karyotype?
62. What is meant by sex-linked trait?
63. What is mutation? What do you mean by mutations? Define mutation and differentiate between chromosomal aberration and point mutation.
64. What is nuclein?
65. What is nucleosomes?
66. What is one gene/ one polypeptide?
67. What is phosphodiester bond or linkage?
68. What is phosphodiester linkage? Draw structural formula. What is phosphodiester bond or linkage?
69. What is primer?
70. What is Semi-conservative replication of DNA?
71. What is sickle cell anemia?
72. What is telocentric chromosome?
73. What is the composition of chromosomes?
74. What is the difference between the acrocentric and sub metacentric chromosomes?
75. What is the function RNA Polymerase in transcription?
76. What is the genetic code?
77. What is the length of a strand of DNA from a single chromosome?
78. What is the length of Okazaki fragments?
79. What is the normal and the mutant eye colour of Drosophila?
80. What is the normal number of chromosomes in mosquito, honeybee, corn, frog, mouse and man?
81. What is the number of chromosomes in Penicillin and ferns?
82. What is the number of nucleotides in the DNA of a typical human chromosome?
83. What is the role of DNA polymerase I?
84. What is the structure of a typical nucleotide?
85. What is the work of Chargaff?
86. What is transcription?
87. What is transformation?
88. What is translation?
89. What is triplet code?
90. What is X-ray diffraction?
91. What was work of Meselson-Stahl?
92. When and where were the chromosomes first seen by whom?
93. Where codon and anticodon are situated?
94. Which codons are called stop codons and consense codon and why?OR what are non-sense codons?Quote examples?
95. Which type of streptococcus pneumonia bacteria are virulent, those with polysaccharide coat or without it?
96. Who and when proposed the chromosomal theory of inheritance?
97. Who first observed the chromosomes?
98. Who prepared the X-ray diffraction of DNA?
99. Who presented the model of the structure of DNA and when?
100. Who proposed the double helical structure of DNA?
101. Who provided first evidence that ‘DNA’ is the hereditary material?
102. Who repeated the experiments of Griffith?
103. Why hershey and chase are famous for?
104. Why histones are positively charged as against most of the proteins which are negatively?
105. Why histones are positively charged?

Long Questions

1. Define and explain transcription in detail. What is transcription? How it occurs?
2. Define and explain translation.
3. Describe how Griffith experiments to prove that DNA is the heredity material.
4. Describe how Hershey and Chase prove that DNA is hereditary material.
5. Describe how Hershey and Chase prove that DNA is the heredity material.
6. Describe one gene/one polypeptide hypothesis considering the work of Beadle and Tatum. What hypothesis did Beadle and Tatum test in their experiment on Neurospora.
7. Describe process of translation.
8. Describe the chemical composition of chromosome. What do you know about their types?
9. Describe the different types of RNA with their roles.
10. Describe the one gene/one polypeptide hypothesis considering the work of Beadle and Tatum.
11. Describe the Watson – Crick model of DNA in detail.
12. Describe the work of Beadle and Tatum on Neurospora.
13. Describe Watson-Crick Model of DNA in detail.
14. Explain double helical structure of DNA.
15. Explain how DNA encodes protein structure.
16. Explain Meselson and Stahl’s experiment. Describe Meselson and Stahl’s experiment to show semi-conservative replication.
17. How did Meselson and Stahl show that DNA replication is semi conservative?
18. How it was prove that DNA is the hereditary material?
19. Prove that DNA is the heredity material.
20. What are chromosomes? What do you know about their number, karyotype, types and shapes? Describe types of chromosomes on the basis of centromere.
21. What is genetic code? Describe its characteristics.
22. What is transcription? Explain the process with the help of diagram.
23. Write a note on genetic code.
24. Write the process of replication of DNA.

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