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Free Download as PDF of the detailed solutions for class 12 Biology from NCERT or CBSE text book as per exam pattern, to help you in day to day learning. We provide all important questions and answers from chapter Molecular Basis of Inheritance of Biology.
61
Link together two pieces of DNA
[1]
Link together two pieces of DNA
[2]
Cut DNA at specific locations
[3]
Restrict elongation of DNA
[4]
Restrict DNA replication
Answer: Cut DNA at specific locations
62
The sequence of structural gene in lac operon concept is
[1]
lac Y, lac Z, lac A
[2]
lac Z, lac Y, lac A
[3]
lac A, lac Y, lac Z
[4]
lac A, lac Z, lac Y
Answer: lac Z, lac Y, lac A
63
mRNA directs the building of proteins through a sequence of
[1]
Introns
[2]
Codons
[3]
Exons
[4]
Anticodons
64
In the DNA molecule:
[1]
There are two strands which run antiparallel-one in 5′ → 3′ direction and other in 3′ → 5′
[2]
There are two strands which run parallel in the 5′ → 3′ direction
[3]
The proportion of Adenine in relation to thymine varies with the organism
[4]
The total amount of purine nucleotides and pyrimidine nucleotides is not always equal
Answer: There are two strands which run antiparallel-one in 5′ → 3′ direction and other in 3′ → 5′
65
What are those structures that appear as 'beads-on-string' in the chromosomes when viewed under electron microscope?
[1]
Base pairs
[2]
Genes
[3]
Nucleotides
[4]
Nucleosomes
66
The sections of a structural gene that are expressed are the ______.
[1]
Interferons
[2]
Neurons
[3]
Introns
[4]
Exons
67
Which one of the following techniques made it possible to genetically engineer living organisms?
[1]
Heavier isotope labelling
[2]
Hybridization
[3]
Recombinant DNA techniques
[4]
X-ray diffraction
Answer: Recombinant DNA techniques
68
The sequence of nitrogen bases in a particular region of the noncoding strand of a DNA molecule was found to be CAT GTT TAT CGC. What would be the sequence of nitrogen bases in the mRNA that is synthesized by the corresponding region of the coding strand in that DNA?
[1]
GUA CAA AUA GCC
[2]
GTA CAA ATA GCC
[3]
CAU GUU UAU CGG
[4]
CAA GAA TAU GCC
69
Enzyme responsible for reverse transcription is :
[1]
Reverse transcriptase
[2]
DNA polymerase
[3]
RNA polymerase
[4]
RNA dependent RNA polymerase
Answer: Reverse transcriptase
70
Gel electrophoresis is used for
[1]
Isolation of DNA molecule
[2]
Cutting of DNA into fragments
[3]
Separation of DNA fragments according to their size
[4]
Construction of recombinant DNA by joining with cloning vectors
Answer: Separation of DNA fragments according to their size
71
What is not true for genetic code?
[1]
It is unambiguous
[2]
A codon in mRNA is read in a non-contiguous fashion
[3]
It is nearly universal
[4]
It is degenerate
Answer: A codon in mRNA is read in a non-contiguous fashion
72
Chromosome is made up of
[1]
DNA + pectin
[2]
RNA + DNA
[3]
DNA + Histone
[4]
Only histone
73
What would happen if in a gene encoding a polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA
[1]
A polypeptide of 24 amino acids will be formed
[2]
A polypeptide of 25 amino acids will be formed
[3]
A polypeptide of 49 amino acids will be formed
[4]
Two polypeptides of 24 and 25 amino acids will be formed
Answer: A polypeptide of 24 amino acids will be formed
74
The anti-parallel nature of DNA refers to
[1]
Its charged phosphate groups
[2]
The opposite direction of the two strands
[3]
The formation of hydrogen bonds between bases from opposite strands
[4]
The pairing of bases on one strand with bases on the other strand
Answer: The opposite direction of the two strands
75
Protein synthesis in an animal cell occurs
[1]
On ribosomes presents in cytoplasm as well as in mitochondria
[2]
On ribosomes present in the nucleolus as well as in cytoplasm
[3]
Only on ribosomes attached to the nuclear envelope and endoplasmic reticulum
[4]
Only on the ribosomes present in cytosol
Answer: On ribosomes presents in cytoplasm as well as in mitochondria
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