Purines

Q.

Name The Common Pyrimidine for DNA and RNA.

Q.

How many of the following statements are incorrect?

(1) Purine nitrogenous base in a nucleotide is attached to pentose sugar by 1, 1 glycosidic linkage.

(2) Adenosine is a nucleoside.

(3) Genome of E. coli possess 4.6 × 10⁹ base pair.

(4) Pitch of DNA helix is 3.4 A⁰.

(5) Euchromatin stains light.

(6) RNA is not more stable than DNA.

(7) RNA can mutate at faster rate than DNA.

Q.

The statement - ‘Deoxythymidine is a monomer nucleotide of DNA’ is:

1. True
2. False

Q. DNA has in it four types of nitrogen bases. They are

1. None of these.
2. Adenine, uracil, thymine, alanine
3. Adenine, thymine, guanine, cytosine
4. Adenine, thymine, uracil, cytosine

Q. The pyrimidine base which confers additional stability to DNA over RNA is

1. Adenine
2. Guanine
3. Cytosine
4. Uracil
5. Thymine

Q. Identify the group which contains only pyrimidines.

1. Uracil, cytosine
2. Guanine, uracil and cytosine
3. Adenine, guanine
4. Adenine, cytosine

Q. Purines found both in DNA and RNA are

1. cytosine and thymine
2. adenine and thymine
3. adenine and guanine
4. guanine and cytosine

Q. Which of the following nucleotide bases is found only in DNA, not in RNA?

1. Guanine
2. Thymine
3. Uracil
4. Adenine

Q.

Purines are the same in both DNA and RNA.

1. True

2. False

Q. In a segment of DNA with 120 adenine and 120 cytosine, the total number of nucleotides in that segment would be

1. 280
2. 640
3. 480
4. 240

Q. Which of the following are purines in DNA?

1. Cytosine
2. Gunaine
3. Adenine
4. Uracil

Q. Read and select the correct and incorrect statement.
1) The four nucleotide bases are not necessarily present in DNA in exactly equal proportions.
2) The total amount of purines is equal to the total amount of pyrimidines.
3) DNA ligase enzyme act to hydrolyze or breakdown a polynucleotide chain into its component nucleotides.
4) Nuclease enzymes are capable of restoring an intact DNA duplex.

1. 2 is correct but 1, 3 and 4 are incorrect.
2. 2, 3 and 4 are correct but 1 is incorrect.
3. 1 and 2 are incorrect but 3 and 4 are correct.
4. 1, 2 and 3 are correct.

Q.

Purines are the same in both DNA and RNA.

1. True

2. False

Q. Cyclic adenosine monophosphate was discovered by

1. Bekhor et al
2. E.W. Sutherland
3. Beerman
4. Weismann

Q. what will happen if histones were to be mutated made rich in glutamine, spartic acid in place of basic acids??

Q. If the sequence of bases in DNA is ATTCGATG, then the sequence of bases in its transcript will be

1. AUUCGAUG
2. CAUCGAAU
3. UAAGCUAC
4. GUAGCUUA

Q. Purines bond with __________ by forming hydrogen bonds.

1. only purines
2. both purines and pyrimidines
3. either purines or pyrimidines
4. only pyrimidines

Q. Purines found both in DNA and RNA are

1. cytosine and thymine
2. adenine and thymine
3. adenine and guanine
4. guanine and cytosine

Q. Which of the following are purines in DNA?

1. Cytosine
2. Gunaine
3. Adenine
4. Uracil