12th Class Biology Molecular basis of Inheritance / विरासत का आणविक आधार Question Bank

done Case Based - Molecular Basis of Inheritance Total Questions - 28

• question_answer1)

  Direction: Read the following and answer the questions from given below

  The Meselson and Stahl experiment was an experiment to prove that DNA replication was semiconservative and it was first shown in Escherichia coli and subsequently in higher organisms, such as plants and human cells. Semiconservative replication means that when the double stranded DNA helix was replicated, each of the two double-stranded helices consisted of one strand coming from the parental helix and one is newly synthesised.

  (i) The heavy isotope used by Meselson and Stahl for proving the semiconservative mode of DNA is/are

  A)
  \[^{15}N{{H}_{4}}Cl\]                        done clear
  B)
  \[^{14}N{{H}_{3}}C{{l}_{2}}\] done clear
  C)
  \[^{13}N{{H}_{2}}C{{l}_{3}}\]                      done clear
  D)
  All of these done clear
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• question_answer2)

  Direction: Read the following and answer the questions from given below

  The Meselson and Stahl experiment was an experiment to prove that DNA replication was semiconservative and it was first shown in Escherichia coli and subsequently in higher organisms, such as plants and human cells. Semiconservative replication means that when the double stranded DNA helix was replicated, each of the two double-stranded helices consisted of one strand coming from the parental helix and one is newly synthesised.

  (ii) Heavy DNA can be differentiated from normal DNA by which centrifugation technique?

  A)
  AgCI density gradient done clear
  B)
  CsCI density gradient done clear
  C)
  \[CaS{{O}_{4}}\], density gradient done clear
  D)
  KCI density gradient done clear
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• question_answer3)

  Direction: Read the following and answer the questions from given below

  The Meselson and Stahl experiment was an experiment to prove that DNA replication was semiconservative and it was first shown in Escherichia coli and subsequently in higher organisms, such as plants and human cells. Semiconservative replication means that when the double stranded DNA helix was replicated, each of the two double-stranded helices consisted of one strand coming from the parental helix and one is newly synthesised.

  (iii) Similar experiments like Meselson and Stahl was performed by Taylor in 1958. The experimental organism of Taylor was

  A)
  Vicia faba          done clear
  B)
  Fungi done clear
  C)
  E. coli               done clear
  D)
  Protista done clear
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• question_answer4)

  Direction: Read the following and answer the questions from given below

  The Meselson and Stahl experiment was an experiment to prove that DNA replication was semiconservative and it was first shown in Escherichia coli and subsequently in higher organisms, such as plants and human cells. Semiconservative replication means that when the double stranded DNA helix was replicated, each of the two double-stranded helices consisted of one strand coming from the parental helix and one is newly synthesised.

  (iv) Radioisotope used by Taylor in his experiment was

  A)
  iron                   done clear
  B)
  titanium done clear
  C)
  thymidine     done clear
  D)
  copper done clear
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• question_answer5)

  Direction: Read the following and answer the questions from given below

  The Meselson and Stahl experiment was an experiment to prove that DNA replication was semiconservative and it was first shown in Escherichia coli and subsequently in higher organisms, such as plants and human cells. Semiconservative replication means that when the double stranded DNA helix was replicated, each of the two double-stranded helices consisted of one strand coming from the parental helix and one is newly synthesised.

  (v) Given diagram depicts the experiment of Meselson and Stahl.

  Which of the following is correctly depicted above?

  I. Equal amount of light DNA and hybrid DNA was observed in E. coli culture after one generations.

  II. The generation time of E. coli culture was 40 minutes.

  III. Equal amount of light DNA and hybrid DNA was observed in E. coli culture after two generations.

  A)
  I and II                          done clear
  B)
  Only III done clear
  C)
  I and III                         done clear
  D)
  II and III done clear
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• question_answer6)

  Direction: Read the following and answer the questions from given below Erwin Chargaff was one of those men, making two discoveries that led James Watson and Francis Crick to the double helix structure of DNA. At first Chargaff noticed that DNA whether taken from a plant or animal-contained equal amounts of adenine and thymine and equal amounts of cytosine and guanine. These equalities provides clues into the chemical pairing that make up the double helix. In addition Chargaff also found that amounts of guanine, cytosine, adenine and thymine vary by species are indication that DNA, not protein might be the genetic material for life.

  (i) Thymine is also called

  A)
  2 methyl uracil               done clear
  B)
  3 methyl uracil done clear
  C)
  4 methyl uracil               done clear
  D)
  5 methyl uracil done clear
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• question_answer7)

  Direction: Read the following and answer the questions from given below Erwin Chargaff was one of those men, making two discoveries that led James Watson and Francis Crick to the double helix structure of DNA. At first Chargaff noticed that DNA whether taken from a plant or animal-contained equal amounts of adenine and thymine and equal amounts of cytosine and guanine. These equalities provides clues into the chemical pairing that make up the double helix. In addition Chargaff also found that amounts of guanine, cytosine, adenine and thymine vary by species are indication that DNA, not protein might be the genetic material for life.

  (ii) Which one of the following ratio is constant in DNA of different species?

  A)
  A+T/C+G       done clear
  B)
  A+G/T+C done clear
  C)
  A+C/U+G                    done clear
  D)
  A+U/C+G done clear
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• question_answer8)

  Direction: Read the following and answer the questions from given below Erwin Chargaff was one of those men, making two discoveries that led James Watson and Francis Crick to the double helix structure of DNA. At first Chargaff noticed that DNA whether taken from a plant or animal-contained equal amounts of adenine and thymine and equal amounts of cytosine and guanine. These equalities provides clues into the chemical pairing that make up the double helix. In addition Chargaff also found that amounts of guanine, cytosine, adenine and thymine vary by species are indication that DNA, not protein might be the genetic material for life.

  (iii) In sea urchin DNA which is double stranded 17% of the bases were shown to be cytosine. The percentages of the other three bases expected to be present in this DNA are

  A)
  G/34%, A/24.5% T/24.5% done clear
  B)
  G/17%, A/16.5%, T/32.5% done clear
  C)
  G/17%, A/33%, T/33% done clear
  D)
  G/8.5%, A/50%, T/24.5% done clear
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• question_answer9)

  Direction: Read the following and answer the questions from given below Erwin Chargaff was one of those men, making two discoveries that led James Watson and Francis Crick to the double helix structure of DNA. At first Chargaff noticed that DNA whether taken from a plant or animal-contained equal amounts of adenine and thymine and equal amounts of cytosine and guanine. These equalities provides clues into the chemical pairing that make up the double helix. In addition Chargaff also found that amounts of guanine, cytosine, adenine and thymine vary by species are indication that DNA, not protein might be the genetic material for life.

  (iv) In a DNA strand of length 340 A, there are

  A)
  100 nucleotides done clear
  B)
  100 base pairs done clear
  C)
  100 nitrogenous bases done clear
  D)
  100 sugar phosphates done clear
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• question_answer10)

  Direction: Read the following and answer the questions from given below Erwin Chargaff was one of those men, making two discoveries that led James Watson and Francis Crick to the double helix structure of DNA. At first Chargaff noticed that DNA whether taken from a plant or animal-contained equal amounts of adenine and thymine and equal amounts of cytosine and guanine. These equalities provides clues into the chemical pairing that make up the double helix. In addition Chargaff also found that amounts of guanine, cytosine, adenine and thymine vary by species are indication that DNA, not protein might be the genetic material for life.

  (v) Assertion [A] If the sequence of bases of one DNA strand is known then the sequence of other strand can be predicted.

  Reason [R] Both the strands of DNA are complementary to each other.

  A)
  If both A and R are true and R is the correct explanation of A done clear
  B)
  if both A and R are true, but R is not the correct explanation of A done clear
  C)
  If A is true, but R is false done clear
  D)
  If A is false, but R is true done clear
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• question_answer11)

  Direction: Read the following and answer the questions from given below A codon is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases. There are 64 different codons out of which 61 specify amino acids while the remaining three are used as stop signals. So, each sequence of three codes for an amino acid and proteins are made up of sometimes hundreds of amino acids. So, the code that would make one protein could have hundreds, sometimes even thousands of triplets contained in it.

  (i) Degeneracy refers to

  A)
  one amino acid has more than one code triplet done clear
  B)
  one amino acid has only one code triplet done clear
  C)
  codons which specify the same amino acids differ only in the third base of the triplet done clear
  D)
  Both [a] and [c] done clear
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• question_answer12)

  Direction: Read the following and answer the questions from given below A codon is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases. There are 64 different codons out of which 61 specify amino acids while the remaining three are used as stop signals. So, each sequence of three codes for an amino acid and proteins are made up of sometimes hundreds of amino acids. So, the code that would make one protein could have hundreds, sometimes even thousands of triplets contained in it.

  (ii) Starting codon is universal means

  A)
  it is same universally for all organisms done clear
  B)
  two or more codons done clear
  C)
  any variable code is called starting which can start protein synthesis done clear
  D)
  all codons originated from same starting codon done clear
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• question_answer13)

  Direction: Read the following and answer the questions from given below A codon is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases. There are 64 different codons out of which 61 specify amino acids while the remaining three are used as stop signals. So, each sequence of three codes for an amino acid and proteins are made up of sometimes hundreds of amino acids. So, the code that would make one protein could have hundreds, sometimes even thousands of triplets contained in it.

  (iii) The features of genetic code that allow bacteria to produce human insulin by recombinant DNA technology is

  A)
  genetic code is redundant done clear
  B)
  genetic code is nearly universal done clear
  C)
  genetic code is specific done clear
  D)
  genetic code is not ambiguous done clear
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• question_answer14)

  Direction: Read the following and answer the questions from given below A codon is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases. There are 64 different codons out of which 61 specify amino acids while the remaining three are used as stop signals. So, each sequence of three codes for an amino acid and proteins are made up of sometimes hundreds of amino acids. So, the code that would make one protein could have hundreds, sometimes even thousands of triplets contained in it.

  (iv) The codons of glycine are

  A)
  CCU, CCC, CCA, CCG done clear
  B)
  CGU, CGC, CGA, CGG done clear
  C)
  GGU, GGC, GGA, GGG done clear
  D)
  ACU, ACC, ACA, ACG done clear
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• question_answer15)

  Direction: Read the following and answer the questions from given below A codon is a trinucleotide sequence of DNA or RNA that corresponds to a specific amino acid. The genetic code describes the relationship between the sequence of DNA bases (A, C, G and T) in a gene and the corresponding protein sequence that it encodes. The cell reads the sequence of the gene in groups of three bases. There are 64 different codons out of which 61 specify amino acids while the remaining three are used as stop signals. So, each sequence of three codes for an amino acid and proteins are made up of sometimes hundreds of amino acids. So, the code that would make one protein could have hundreds, sometimes even thousands of triplets contained in it.

  (v) Read the sequence of nucleotide in the given segment of mRNA and the respective amino acid sequence in the polypeptide chain to answer the question as follows.

  \[\begin{align}   & mRNA \\  & polypeptide \\ \end{align}\] \[\frac{AUG\,\,UUU\,\,AUG\,\,CCU\,\,GUU\,\,UCU\,\,UAA}{Met-Phe-Met-Po-Val-Ser}\]

  Following conclusion can be made from this

  I. The nucleotide sequence of the DNA strand from which this mRNA was transcribed is TAC AAU TAC GCA CAA AGA ATT.

  II. Codes for proline and valine are CCU and GUU, respectively.

  III. AUG is also known as start codon.

  IV. UAA does not code any amino acid.

  A)
  I and II are incorrect done clear
  B)
  III and IV are correct done clear
  C)
  I and IV are incorrect done clear
  D)
  I, II and III and IV are correct done clear
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• question_answer16)

  Direction: Read the following and answer the questions from given below Transfer RNA (tRNA) serves as the nucleic acid decoding device that reads the triplet genetic code of messenger RNA (mRNA) and causes the insertion of codon-specific amino acids in a growing protein chain during the process of translation in the ribosome. A particular triplet codon in a mRNA is read by a dRNA through one of its loop, which has triplet of anticodon residues that base pair with the codon. Each <RNA is charged with a particular amino acid at its 3' end.

  (i) The presence of an adaptor molecule that would on one hand read the code and on the other hand would bind to specific amino acids was postulated by

  A)
  Francis Crick      done clear
  B)
  James Watson done clear
  C)
  Rosalind Franklin            done clear
  D)
  Griffith done clear
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• question_answer17)

  Direction: Read the following and answer the questions from given below Transfer RNA (tRNA) serves as the nucleic acid decoding device that reads the triplet genetic code of messenger RNA (mRNA) and causes the insertion of codon-specific amino acids in a growing protein chain during the process of translation in the ribosome. A particular triplet codon in a mRNA is read by a dRNA through one of its loop, which has triplet of anticodon residues that base pair with the codon. Each <RNA is charged with a particular amino acid at its 3' end.

  (ii) The difference between mRNA and tRNA is that

  A)
  mRNA has more elaborated 3-dimentional structure due to extensive base pairing done clear
  B)
  mRNA bears anticodon, but tRNA has codons done clear
  C)
  tRNA has more elaborated 3-dimentional structure due to extensive base pairing done clear
  D)
  mRNA is usually smaller than tRNA done clear
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• question_answer18)

  Direction: Read the following and answer the questions from given below Transfer RNA (tRNA) serves as the nucleic acid decoding device that reads the triplet genetic code of messenger RNA (mRNA) and causes the insertion of codon-specific amino acids in a growing protein chain during the process of translation in the ribosome. A particular triplet codon in a mRNA is read by a dRNA through one of its loop, which has triplet of anticodon residues that base pair with the codon. Each <RNA is charged with a particular amino acid at its 3' end.

  (iii) Before the genetic code was postulated, the tRNA was called

  A)
  rRNA (ribosomal RNA) done clear
  B)
  mRNA (messenger RNA) done clear
  C)
  sRNA(soluble RNA) done clear
  D)
  sedimentary RNA done clear
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• question_answer19)

  Direction: Read the following and answer the questions from given below Transfer RNA (tRNA) serves as the nucleic acid decoding device that reads the triplet genetic code of messenger RNA (mRNA) and causes the insertion of codon-specific amino acids in a growing protein chain during the process of translation in the ribosome. A particular triplet codon in a mRNA is read by a dRNA through one of its loop, which has triplet of anticodon residues that base pair with the codon. Each <RNA is charged with a particular amino acid at its 3' end.

  (iv) tRNA binds to mRNA through

  A)
  anticodon loop done clear
  B)
  T\[\Psi \]C loop done clear
  C)
  amino acid binding loop done clear
  D)
  D-loop done clear
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• question_answer20)

  Direction: Read the following and answer the questions from given below Transfer RNA (tRNA) serves as the nucleic acid decoding device that reads the triplet genetic code of messenger RNA (mRNA) and causes the insertion of codon-specific amino acids in a growing protein chain during the process of translation in the ribosome. A particular triplet codon in a mRNA is read by a dRNA through one of its loop, which has triplet of anticodon residues that base pair with the codon. Each <RNA is charged with a particular amino acid at its 3' end.

  (v)

  Following statements are related to the above figure of tRNA.

  I. It has an anticodon loop that has bases complementary to the code.

  II. It has an amino acid acceptor end to which it binds to amino acids.

  III. It is not specific for each amino acid.

  Choose the correct option.

  A)
  I and III                         done clear
  B)
  II and III done clear
  C)
  I, II and III                     done clear
  D)
  I and II done clear
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• question_answer21)

  Observe the diagram given below of a nucleosome model and answer the following questions.

  (i) The number of nucleosomes present in human cell is

   
  A)
  \[3.3\times {{10}^{7}}\] nucleosome done clear
  B)
  \[1.1\times {{10}^{7}}\] nucleosome done clear
  C)
  \[6.6\times {{10}^{7}}\] nucleosome done clear
  D)
  Indefinite done clear
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• question_answer22)

  Observe the diagram given below of a nucleosome model and answer the following questions.

  (ii) Which amino acids are present in histones?

  A)
  Lysineand histidine done clear
  B)
  Valineand histidine done clear
  C)
  Arginineand lysine done clear
  D)
  Arginineand histidine done clear
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• question_answer23)

  Observe the diagram given below of a nucleosome model and answer the following questions.

  (iii) Linker DNA is

  A)
  a part of nucleosome done clear
  B)
  a part that joins two octamer cores done clear
  C)
  ssDNA done clear
  D)
  Both [a] and [b] done clear
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• question_answer24)

  Observe the diagram given below of a nucleosome model and answer the following questions.

  (iv) The association of histone HI with a nucleosome indicates

  A)
  transcription is occurring done clear
  B)
  DNA replication is occurring done clear
  C)
  the DNA is condensed into a chromatin fibre done clear
  D)
  the DNA double helix is exposed done clear
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• question_answer25)

  Observe the diagram given below of Hershey and Chase experiment and answer the following questions.

  (i) In Hershey and Chase experiment, bacteriophage nucleic acids were labelled as

  A)
  \[^{32}P\] labelled phosphate done clear
  B)
  \[^{3}H\] labelled \[{{H}_{2}}O\] done clear
  C)
  \[^{35}S\]labelled sulphate done clear
  D)
  \[^{14}C\] labelled \[C{{O}_{2}}\] done clear
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• question_answer26)

  Observe the diagram given below of Hershey and Chase experiment and answer the following questions.

  (ii) Bacteriophage protein coat was labelled by ......... in Hershey and Chase experiment.

  A)
  \[^{32}S\] labelled sulphur done clear
  B)
  \[^{32}S\] labelled sulphate done clear
  C)
  \[^{32}S\] labelled sulphur done clear
  D)
  \[^{32}S\] labelled sulphate done clear
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• question_answer27)

  Observe the diagram given below of Hershey and Chase experiment and answer the following questions.

  (iii) In Hershey and Chase experiment, radioactive 32 P was used to culture bacteriophage which resulted in radioactive

  A)
  viral DNA done clear
  B)
  bacterial capsule done clear
  C)
  viral protein done clear
  D)
  plasma membrane of bacteria done clear
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• question_answer28)

  Observe the diagram given below of Hershey and Chase experiment and answer the following questions.

  (iv) DNA with labelled thymidine is added to a medium where Escherichia coli is growing. After 5 minutes of growth

  A)
  all the DNA strands of parents and daughters will show DNA with labelled thymidine done clear
  B)
  only parental strands will show thymidine labelled DNA done clear
  C)
  all the strands of daughters will be thymidine labelled done clear
  D)
  half the daughter strands will have labelled and half strands without labelled thymidine done clear
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