Given below are two statements: One is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A):
Semiconservative replication was experimentally proved by Mathew Meselson and Franklin Stahl (1958)
Reason (R):
Meselson and Stahl used radioactive isotope \(^{15}N\) and equilibrium density gradient centrifugation technique.
In the light of the above statements, choose the correct answer from the options given below:
1.
(A) is True but (R) is False.
2.
(A) is False but (R) is True.
3.
Both (A) and (R) are True and (R) is the correct explanation of (A).
4.
Both (A) and (R) are True but (R) is not the correct explanation of (A).
In the light of the above statements, choose the correct answer from the options given below:
Subtopic: DNA Replication |
From NCERT
NEET - 2022
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With respect to nucleosome, which of the following statements is incorrect ?
| 1. | Nucleosome contains 120 bp of DNA helix. |
| 2. | Nucleosomes are seen as 'beads' on string' under Electron Microscope. |
| 3. | DNA is wrapped around positively charged histone octamer to form nucleosome. |
| 4. | Nucleosome is the repeating unit of chromatin. |
Subtopic: DNA Packaging |
87%
From NCERT
NEET - 2022
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One of the strands of double stranded DNA has base composition as follows: 15% A, 15% T, 40%G and 30%C. What will be the percentage of these bases in the complementary strand ?
1. 15% A, 15% T, 30% G , 40% C
2. 15% A, 30% T, 40% G , 15% C
3. 15% A, 15% T, 40% G , 30% C
4. 15% A, 40% T, 15% G , 30% C
Subtopic: DNA Double Helix |
62%
From NCERT
NEET - 2022
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What would be the proportions of light and hybrid density DNA molecule, respectively if Meselson and Stahl's experiment was continued for 60 minutes?
1. 50%, 50%
2. 25%, 75%
3. 75%, 25%
4. 100%, 0%
Subtopic: DNA Replication |
68%
From NCERT
NEET - 2022
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If a DNA molecule is shortened by 25 base pairs, how many helical turns will be reduced from its structure?
1. 1
2. 3
3. 2.5
4. 2
1. 1
2. 3
3. 2.5
4. 2
Subtopic: DNA Double Helix |
85%
From NCERT
NEET - 2022
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Gene expression might be altered at the level of post-transcriptional processing in eukaryotes rather than prokaryotes because of which of the following?
1. Eukaryotic mRNAs get 5' caps and 3' tails.
2. Prokaryotic genes are expressed as mRNA, which is more stable in the cell.
3. Eukaryotic exons may be spliced in alternative patterns.
4. Prokaryotes use ribosomes of different structure and size
1. Eukaryotic mRNAs get 5' caps and 3' tails.
2. Prokaryotic genes are expressed as mRNA, which is more stable in the cell.
3. Eukaryotic exons may be spliced in alternative patterns.
4. Prokaryotes use ribosomes of different structure and size
Subtopic: Transcription: I | Transcription:II | Translation |
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Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately, what percentage of the nucleotides in this sample will be thymine?
1. 8%
2. 16%
3. 31%
4. 42%
1. 8%
2. 16%
3. 31%
4. 42%
Subtopic: The DNA |
83%
From NCERT
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In the following questions a statement of assertion (A) is followed by a statement of reason (R).
| Assertion (A): | Expressed sequence tags (ESTS) which was used in human genome project it identify all the genes that are expressed as DNA. |
| Reason (R): | Complete DNA sequence is decoded. |
| 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. | Both (A) and (R) are false. |
- If both the assertion and the reason are true and the reason is a correct explanation of the assertion
- If both the assertion and reason are true but the reason is not a correct explanation of the assertion
- If the assertion is true but the reason is false
- If both the assertion and reason are false
Subtopic: Human Genome Project |
54%
From NCERT
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A:
During transcription DNA strand with 5’-3’ polarity is refered
as coding strand.
R: Coding strand codes for RNA.
In the following questions a statement of assertion (A) is followed by a statement of reason (R).
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
3. If Assertion is true statement but Reason is false, then mark (3)
4. If both Assertion and Reason are false statements, then mark (4)
R: Coding strand codes for RNA.
In the following questions a statement of assertion (A) is followed by a statement of reason (R).
1. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
2. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2)
3. If Assertion is true statement but Reason is false, then mark (3)
4. If both Assertion and Reason are false statements, then mark (4)
- If both the assertion and the reason are true and the reason is a correct explanation of the assertion
- If both the assertion and reason are true but the reason is not a correct explanation of the assertion
- If the assertion is true but the reason is false
- If both the assertion and reason are false
Subtopic: Transcription: I | Transcription:II |
70%
From NCERT
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The "universal" genetic code is now known to have exceptions. Evidence for this can be found if which of the following is true?
| 1. | If UGA, usually a stop codon, is found to code for an amino acid such as tryptophan (usually coded for by UGG only). |
| 2. | If one stop codon, such as UGA, is found to have a different effect on translation than another stop codon, such as UAA. |
| 3. | If prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide. |
| 4. | If several codons are found to translate to the same amino acid, such as serine. |
Subtopic: Genetic Code |
From NCERT
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