Class 12 Science Biology Chapter 6 MCQ With Answers
Check the below NCERT MCQ Questions for Class 12 Biology Chapter 6 Molecular Basis of Inheritance with Answers Pdf free download. MCQ Questions for Class 12 Biology with Answers were prepared based on the latest exam pattern. We have provided Molecular Basis of Inheritance Class 12 Biology MCQs Questions with Answers to help students understand the concept very well.
Biology Class 12 Chapter 6 MCQs on Molecular Basis of Inheritance
Question 1.
Represser Lac-Operon protein attached to:
(a) Operator
(b) Inducer
(c) Regulator
(d) β-Glacto sidase
Answer
Answer: (b) Inducer
Question 2.
Following is important in Ïranscription:
(a) DNA Methylase
(b) CAAT Box
(c) Promotar
(d) DNA Polymerase
Answer
Answer: (a) DNA Methylase
Question 3.
Anticodon found in:
(a) On DNA
(b) On t-RNA
(c) On r-RNA
(d) On m-RNA
Answer
Answer: (b) On t-RNA
Question 4.
In DNA helix:
(a) Quadrate structure
(b) Polarity
(c) Antiparallel Polarity
(d) Disuiphide bond
Answer
Answer: (c) Antiparallel Polarity
Question 5.
During splicing axon attached and inducer enzyme for reaction:
(a) RNA Ligase
(b) RNA Catalase
(c) RNA permease
(d) RNA poloymerase
Answer
Answer: (b) RNA Catalase
Question 6.
During DNA synthesis formed segment is:
(a) Polymerase fragment
(b) RNA fragment
(c) Okazaki fragment
(d) RNA Primer
Answer
Answer: (c) Okazaki fragment
Question 7.
In a give DNA segment ATC ACC AGG ACC CCA ACA, the first base gets mutated. The effect of this on coding by the DNA segment will result in :
(a) One amino acid less in protein
(b) No change in the sequence
(c) Complete change in the type and sequence of amino acid
(d) Change in first amino acid only
Answer
Answer: (b) No change in the sequence
Question 8.
DNA fragments are joined in a correct sequence by :
(a) DNA ligase
(b) RNA polymerase
(c) Helicase
(d) DNA polymerase
Answer
Answer: (b) RNA polymerase
Question 9.
The ratio constant for a species is :
(a) T+C/G + A
(b) A+C/T + G
(c) G + G/A + T
(d) A + C/C + T
Answer
Answer: (b) A+C/T + G
Question 10.
DNA repairing is done by:
(a) By DNA polymerase I
(b) By DNA Polymerase II
(c) Both (a) and (b)
(d) By Ligase
Answer
Answer: (b) By DNA Polymerase II
Question 11.
A ribotide is made up of:
(a) Ribose + Phosphate + Uracil
(b) Deoxribose + Uracil + Phosphate
(c) Thymine + Ribose + Phosphate
(d) Deoxyribpse + Phosphate + Adenine
Answer
Answer: (a) Ribose + Phosphate + Uracil
Question 12.
the enzyme involved in transcription is:
(a) DNA Polymerase I
(b) DNA Polymerase II
(c) RNA Polymerase
(d) DNA Polymerase
Answer
Answer: (d) DNA Polymerase
Question 13.
Antiparallel strands of a DNA molecule means that:
(a) One strand turns clockwise
(b) One strand turns anticlockwise
(c) The phosphate groups at the start of two DNA strands are in opposite position
(d) The phosphate groups at the start of two DNA strands, at their ends, share the same position
Answer
Answer: (c) The phosphate groups at the start of two DNA strands are in opposite position
Question 14.
Which one is mainly transcribed:
(a) Only RNA sequence
(b) Middle repetitive DNA sequence
(c) Highly repetitive DNA sequence
(d) Single copy of DNA sequence
Answer
Answer: (c) Highly repetitive DNA sequence
Question 15.
Amino acid sequence, in protein synthesis is decided by the sequence of?
(a) c-DNA
(b) r-RNA
(c) f-RNA
(d) m-RNA
Answer
Answer: (b) r-RNA
Question 16.
DNA multiplication is also called:
(a) Replication
(b) Transduction
(c) Translation
(d) Transcription
Answer
Answer: (b) Transduction
Question 17.
During Protein synthesis, atone point the process comes to a halt. Select the group of the three codons from the following, from which any one of the three could bring about this halt:
(a) UUC, UUA, UAC
(b) UAG, UGA, UAA
(c) UUE, UCA, UCG
(d) UUU, UCC, UAU
Answer
Answer: (b) UAG, UGA, UAA
Question 18.
One turn of the helix in p-from DNA is approximately:
(a) 20 Å
(b) 2 nm
(c) 20 nm
(d) 34 nm
Answer
Answer: (d) 34 nm
Question 19.
Which is not component of lac operon:
(a) Primer gene
(b) Promoter gene
(c) constructive gene
(d) Regulator gene
Answer
Answer: (c) constructive gene
Question 20.
Okazaki fregments is:
(a) RNA primer
(b) small segments of DNA on leading stand
(c) Small segments of DNA on lagging stand
(d) None of these
Answer
Answer: (c) Small segments of DNA on lagging stand
Question 21.
Transposons occur in:
(a) In Eukaryotes
(b) In Prokaryotes
(c) In both (a) and (b)
(d) None of these
Answer
Answer: (c) In both (a) and (b)
Question 22.
One of these is not prepared directly from DNA
(a) m-RNA
(b) f-RNA
(c) r-RNA
(d) Protein
Answer
Answer: (d) Protein
Question 23.
Coiling of DNA duplex is:
(a) Left-handed
(b) Right-handed
(c) Parallel
(d) All of these
Answer
Answer: (c) Parallel
Question 24.
DNA double helix model was given by:
(a) Knoll and Ruska
(b) Khorana
(c) Watson and Crick
(d) Priestley
Answer
Answer: (c) Watson and Crick
Question 25.
Inprokaryotic translation, GTP molecule required in at:
(a) Formation of formyl-met-f-RNA
(b) Joining of 30S sub-unit of ribosome with n-RNA
(c) Joining of 30S m-RNA on Formyl-met-f-RNA
(d) Joining of 50S subunit of ribosome with initiation complex
Answer
Answer: (b) Joining of 30S sub-unit of ribosome with n-RNA
Question 26.
DNA transcription, if nucleotide sequence of DNA strand, that is being coded in ATACG, then the nucleotide sequence in m-RNA would be:
(a) UATGC
(b) TATGC
(c) TCTGG
(d) UAUGC
Answer
Answer: (b) TATGC
Question 27.
In a m-RNA, how many nucleotide sequence code for amino acid:
(a) One
(b) Two
(c) Three
(d) Four
Answer
Answer: (a) One
Question 28.
RNA from which has clover leaf model:
(a) f-RNA
(b) r-RNA
(c) hn-RNA
(d) m-RNA
Answer
Answer: (a) f-RNA
Question 29.
Nitrogenous bases present in DNA:
(a) Adenine, guanine, cytosine, thymine
(b) Adenine, guanine, cytosine, uracil
(c) Adenine, thymine, uracil
(d) Guanine, uracil
Answer
Answer: (a) Adenine, guanine, cytosine, thymine
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