Which among the following statements about the exons is TRUE?
1. They are stop codons.
2. They are start codons. 
3. They are coding sequences.
4. They are intervening sequences. 

Subtopic:  Transcription: I |
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Study the given diagrammatic representation of Griffith's experiment to demonstrate the transformation in bacteria.

Select the option which is incorrectly representing the experiment:
1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (ii) and (iv) 
Subtopic:  Search for Genetic Material |
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Assertion (A):  Primary transcripts in eukaryotes are non-functional. 
Reason (R):  Methyl guanosine triphosphate is attached to 5' -end of hnRNA.
 
1.  Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. (A) is true but (R) is false.
4. (A) is false but (R) is true.
Subtopic:  Transcription: IV |
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The length of DNA is:
I: usually defined as number of nucleotides (or a pair of nucleotide referred to as base pairs) present in it.
II: is the characteristic of an organism.
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
Subtopic:  The DNA |
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Consider the given two statements:
Statement I: A nitrogenous base is linked to the OH of 1'C pentose sugar through a N-glycosidic linkage to form a nucleoside.
Statement II: When a phosphate group is linked to OH of 5'C of a nucleoside through phosphoester linkage, a corresponding nucleotide (or deoxynucleotide depending upon the type of sugar present) is formed.
 
1. Statement I is correct; Statement II is incorrect
2. Statement I is incorrect; Statement II is incorrect
3. Statement I is correct; Statement II is correct
4. Statement I is incorrect; Statement II is correct
Subtopic:  The DNA |
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In the given diagram:
I: A is 3’-5’ direction.
II: B is hydrogen bond.
III: C is phosphodiester bond.
 
1. Only I and II are correct
2. Only II and III are correct
3. I, II and III are correct
4. I, II, and III are incorrect
Subtopic:  DNA Double Helix |
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Deoxythymidine is:
1. a substituted pyrimidine found only in DNA
2. a nucleoside monophosphate found only in DNA
3. a nucleoside found in DNA
4. a nucleotide formed by chemical modifications in a RNA nucleotide
Subtopic:  DNA Double Helix |
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When compared to DNA, in RNA:
I: every nucleotide residue has an additional –OH group present at 3'-position in the ribose.
II: 5-methyl uracil is found instead of thymine.
1. Only I is correct
2. Only II is correct
3. Both I and II are correct
4. Both I and II are incorrect
Subtopic:  DNA vs RNA as Genetic Material |
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In 1953, James Watson and Francis Crick, proposed a very simple but famous Double Helix model for the structure of DNA, based on the X-ray diffraction data produced by:
1. Maurice Wilkins and Rosalind Franklin
2. Beadle and Tatum
3. Temin and Baltimore
4. Avery–MacLeod–McCarty
Subtopic:  DNA Double Helix |
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“For a double stranded DNA, the ratios between Adenine and Thymine and Guanine and Cytosine are constant and equals one” – this statement is known as:
1. Central dogma of molecular biology
2. Chargaff’s rule
3. Tetra-nucelotide hypothesis by Levene
4. Genetic equilibrium
Subtopic:  DNA Double Helix |
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