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 |
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What characteristic of short tandem repeat DNA makes it useful for DNA fingerprinting?
1. The number of repeats varies widely from person to person or animal to animal.
2. The sequence of DNA that is repeated varies, significantly, from individual to individual.
3. The sequence variation is acted upon differently by natural selection in different environments.
4. Every racial and ethnic group has inherited different short tandem repeats.
Subtopic:  DNA Fingerprinting |
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A pyrimidine found uniquely in DNA is:
1. Uracil 2. Thymine
3. Cytosine 4. Guanine
Subtopic:  The DNA |
 82%
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A mutation that inactivates the regulatory gene of a repressible operon in an E. coli cell would result in
1. continuous transcription of the structural gene controlled by that regulator
2. complete inhibition of transcription of the structural gene controlled by that regulator
3. irreversible binding of the repressor to the operator
4.  inactivation of RNA polymerase by alteration of its active site
 
Subtopic:  Gene Regulation: Lac Operon |
 51%
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In the following questions a statement of assertion (A) is followed by a statement of reason (R).
Assertion (A): Histones are basic proteins of major importance in packaging of eukaryotic DNA. DNA and histones comprise chromatin, forming the bulk of eukaryotic chromosome.
Reason (R): Histones are of five major types H1, H2A, H2B and H3 and H4
  
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.
  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  DNA Packaging |
 68%
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A: Exons and introns are present in split genes.
R:  Introns are the information pieces of split genes
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)
 
  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
  3. If the assertion is true but the reason is false
  4. If both the assertion and reason are false
Subtopic:  Transcription: I |
 66%
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Consider the given two statements:
Statement I: In a double stranded DNA molecule, the amount of Guanine should be equal to Cytosine and the amount of Adenine should be equal to Thymine.
Statement II: There are two hydrogen bonds between Adenine and Thymine and three hydrogen bonds between Guanine and Cytosine.
 
1. Both Statement I and Statement II are correct and Statement II correctly explains Statement I
2. Both Statement I and Statement II are correct but Statement II does not correctly explain Statement I
3. Statement I is correct but Statement II is incorrect
4. Statement I is incorrect but Statement II is correct
Subtopic:  DNA Double Helix |
 65%
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Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base?
1. One of the daughter cells, but not the other, would have radioactive DNA.
2. Neither of the two daughter cells would be radioactive.
3.  All four bases of the DNA would be radioactive.
4. DNA in both daughter cells would be radioactive.
 
Subtopic:  DNA Replication |
 53%
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Which of the following provides some evidence that RNA probably evolved before DNA?
1. RNA polymerase uses DNA as a template.
2. RNA polymerase makes a single-stranded molecule.
3.  RNA polymerase does not require localized unwinding of the DNA.
4.   DNA polymerase uses primer, usually made of RNA
Subtopic:  DNA vs RNA as Genetic Material |
 59%
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A section of double stranded DNA is composed of 41% adenine bases. What is the percentage of cytosine bases in this section of DNA? 
1. 18% 
2.  9%
3. 36% 
4. 82% 
Subtopic:  DNA Double Helix |
 90%
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