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NEET - September 2020 Previous Year Questions



NEET Biology Previous Year Questions - September 2020

Match the following columns and select the correct option.

Column-I Column-II
(A)Clostridium butylicum (I)Cyclosporin-A
(B)Trichoderma polysporum (II)Butyric Acid
(C)Monascus purpureus (III)Citric Acid
(D)Aspergillus niger (IV)Blood cholesterol lowering agent

[class-xi ]

  • (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
  • (A)-(II), (B)-(I), (C)-(IV), (D)-(III)
  • (A)-(I), (B)-(II), (C)-(IV), (D)-(III)
  • (A)-(IV), (B)-(II), (C)-(II), (D)-(I)
  • Correct Option: B  [ (A)-(II), (B)-(I), (C)-(IV), (D)-(III) ]

    Remark:

Choose the correct pair from the following:

[class-xii ]

  • Ligases - Join the two DNA molecules
  • Polymerases - Break the DNA into fragments
  • Nucleases - Separate the two strands of DNA
  • Exonucleases - Make cuts at specific positions within DNA
  • Correct Option: A  [
    Ligases - Join the two DNA molecules
    ]

    Remark:

Identify the wrong statement with regard to Restriction Enzymes.

[class-xii ]

  • Each restriction enzyme functions by inspecting the length of a DNA sequence.
  • They cut the strand of DNA at palindromic sites.
  • They are useful in genetic engineering.
  • Sticky ends can be joined by using DNA ligases.
  • Correct Option: D  [ Sticky ends can be joined by using DNA ligases. ]

    Remark:

Match the following columns and select the correct option.

Column-I Column-II
(A)Bt cotton (I)Gene therapy
(B)Adenosine deaminase deficiency (II)Cellular defence
(C)RNAi (III)Detection of HIV infection
(D)PCR (IV)Bacillus thuringiensis

[class-xii ]

  • (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
  • (A)-(III), (B)-(II), (C)-(I), (D)-(IV)
  • (A)-(II), (B)-(III), (C)-(IV), (D)-(I)
  • (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
  • Correct Option: A  [ (A)-(IV), (B)-(I), (C)-(II), (D)-(III) ]

    Remark:

In gel electrophoresis, separated DNA fragments can be visualized with the help of:

[class-xii ]

  • Acetocarmine in bright blue light
  • Ethidium bromide in UV radiation
  • Acetocarmine in UV radiation
  • Ethidium bromide in infrared radiation
  • Correct Option: D  [ Ethidium bromide in infrared radiation ]

    Remark:

Match the organism with its use in biotechnology.

(A)Bacillus thuringiensis (I)Cloning vector
(B)Thermus aquaticus (II)Construction of first rDNA molecule
(C)Agrobacterium tumefaciens (III)DNA polymerase
(D)Salmonella typhimurium (IV)Cry proteins

[class-xii ]

  • (A)-(II), (B)-(IV), (C)-(III), (D)-(I)
  • (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
  • (A)-(III), (B)-(II), (C)-(IV), (D)-(I)
  • (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
  • Correct Option: B  [ (A)-(IV), (B)-(III), (C)-(I), (D)-(II) ]

    Remark:

Bt cotton variety that was developed by the introduction of toxin gene of Bacillus thuringiensis (Bt) is resistant to:

[class-xii ]

  • Insect pests
  • Fungal diseases
  • Plant nematodes
  • Insect predators
  • Correct Option: A  [ Insect pests ]

    Remark:

Which of the following statements is not correct?

[class-xii ]

  • In man insulin is synthesised as a proinsulin.
  • The proinsulin has an extra peptide called C-peptide.
  • The functional insulin has A and B chains linked together by hydrogen bonds.
  • Genetically engineered insulin is produced in E-Coli.
  • Correct Option: C  [ The functional insulin has A and B chains linked together by hydrogen bonds. ]

    Remark:

Which of the following is not an attribute of a population?

[class-xii ]

  • Sex ratio
  • Natality
  • Mortality
  • Species interaction
  • Correct Option: D  [ Species interaction ]

    Remark:

Secondary metabolites such as nicotine, strychnine and caffeine are produced by plants for their:

[class-xii ]

  • Nutritive value
  • Growth response
  • Defence action
  • Effect on reproduction
  • Correct Option: C  [ Defence action ]

    Remark: