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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.
106
The RNA polymerase holoenzyme transcribes:
[1]
the promoter, structural gene and the terminator region
[2]
the promoter, and the
[3]
the structural gene and the terminator regions
[4]
the structural gene only.
Answer: the structural gene and the terminator regions
107
To initiate translation, the mRNA first binds to:
[1]
The smaller ribosomal sub-unit
[2]
The larger ribosomal sub-unit
[3]
The whole ribosome
[4]
No such specificity exists.
Answer: The smaller ribosomal sub-unit
108
Repressor proteins are coded for by ______ genes.
[1]
Structural
[2]
Operator
[3]
Promoter
[4]
Regulator
109
The organelles in the cell where protein synthesis occurs are ______.
[1]
Endoplasmic reticulum
[2]
lNuceus
[3]
Ribosomes
[4]
mRNA
110
PCR and Restriction Fragment Length Polymorphism are the methods fo
[1]
DNA sequencing
[2]
Genetic fingerprinting
[3]
Study of enzymes
[4]
Genetic transformation
Answer: Genetic fingerprinting
111
What is antisense technology?
[1]
RNA polymerase producing DNA
[2]
A cell displaying a foreign antigen used for synthesis of antigens
[3]
Production of somaclonal variants in tissue cultures
[4]
When a piece of RNA that is complementary in sequence is used to stop expression of a specific gene
Answer: When a piece of RNA that is complementary in sequence is used to stop expression of a specific gene
112
A DNA segment which serves as a kind of “on-off switch” for transcription is a/an ______.
[1]
Regulator gene
[2]
Structural gene
[3]
Promoter
[4]
Operator
113
Which one of the following does not follow the central dogma of molecular biology?
[1]
Pea
[2]
Mucor
[3]
HIV
[4]
Chlamydomonas
114
In some viruses, DNA is synthesised by using RNA as template. Such a DNA is called
[1]
A-DNA
[2]
B-DNA
[3]
c DNA
[4]
r DNA
115
Discontinuous synthesis of DNA occurs in one strand, because:
[1]
DNA molecule being synthesised is very long
[2]
DNA dependent DNA polymearse catalyses polymerisation only in one
direction (5’ → 3’)
[3]
it is a more efficient process
[4]
DNA ligase has to have a role
Answer: DNA dependent DNA polymearse catalyses polymerisation only in one
direction (5’ → 3’)
116
Both deoxyribose and ribose belong to a class of sugars called:
[1]
trioses
[2]
hexoses
[3]
pentoses
[4]
polysaccharides
117
Which of the following statements is the most appropriate for sickle cell anaemia?
[1]
It cannot be treated with iron supplements
[2]
It is a molecular disease
[3]
It confers resistance to acquiring malaria
[4]
All of the above
118
Who amongst the following scientists had no contribution in the development of the double helix model for the structure of DNA?
[1]
Rosalind Franklin
[2]
Maurice Wilkins
[3]
Erwin Chargaff
[4]
Meselson and Stahl
Answer: Meselson and Stahl
119
Which of the following steps in transcription is catalysed by RNA polymerse?
[1]
Initiation
[2]
Elongation
[3]
Termination
[4]
All of the above
120
While analysing the DNA of an organism a total number of 5386 nucleotides were found out of which the proportion of different bases were: Adenine = 29%, Guanine= 17%, Cytosine = 32%, Thymine = 17%. Considering the Chargaff’s rule it can be concluded that:
[1]
it is a double stranded circular DNA
[2]
It is single stranded DNA
[3]
It is a double stranded linear DNA
[4]
No conclusion can be drawn
Answer: No conclusion can be drawn
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