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This section includes 27 Mcqs, each offering curated multiple-choice questions to sharpen your Life Sciences knowledge and support exam preparation. Choose a topic below to get started.
1. |
ATP and GTP are __________ |
A. | cells |
B. | receptors |
C. | nucleotides |
D. | nucleic acids |
Answer» D. nucleic acids | |
2. |
Ribozymes are _____________ |
A. | cell organelle |
B. | enzymes |
C. | nucleotide |
D. | nucleoside |
Answer» C. nucleotide | |
3. |
Purines and pyrimidines are different molecules. |
A. | True |
B. | False |
Answer» B. False | |
4. |
How many types of nucleotides are present in DNA? |
A. | 1 |
B. | 2 |
C. | 3 |
D. | 4 |
Answer» E. | |
5. |
What are the types of nucleic acids are found in living organisms? |
A. | deoxyribonucleic acid & nucleotide acid |
B. | deoxyribonucleic acid & ribonucleic acid |
C. | ribonucleic acid & nucleotide acid |
D. | ribonucleic acid & nucleoside acid |
Answer» C. ribonucleic acid & nucleotide acid | |
6. |
Which monomers compose the strands of nucleic acids? |
A. | Amino acids |
B. | Ribose |
C. | Functional groups |
D. | Nucleotides |
Answer» E. | |
7. |
A purified DNA sample of leaf contains 20.0 mole of guanine. Calculate the approximate percentage of purine residues? |
A. | 30% |
B. | 40% |
C. | 60% |
D. | 20% |
Answer» B. 40% | |
8. |
Which of these statements are INCORRECT according to chargaff’s rules? |
A. | The molar ratio of A to T or C to G = 1 |
B. | The sum of purine = sum of pyrimidine |
C. | The % C+G ≠ % A+T |
D. | The composition of DNA remains the same in all the species |
Answer» E. | |
9. |
Which of these statements are TRUE for a glycosidic bond? |
A. | The bond between sugar and the nitrogenous base |
B. | The bond between the two sugar residues |
C. | The bond between sugar and phosphate |
D. | The bond between base and phosphate |
Answer» B. The bond between the two sugar residues | |
10. |
The sugar in RNA is __________ , the sugar in DNA is __________ |
A. | ribose, deoxyribose |
B. | deoxyribose, ribose |
C. | ribose, uracil |
D. | ribose, phosphate |
Answer» B. deoxyribose, ribose | |
11. |
Nucleoside is a pyrimidine or purine base |
A. | ionically bonded to a sugar |
B. | covalently bonded to a sugar |
C. | none of the above |
D. | hydrogen bonded to a sugar |
Answer» C. none of the above | |
12. |
Which of the following is found on RNA but not DNA? |
A. | Deoxyribose |
B. | Uracil |
C. | Adenine |
D. | Phosphate |
Answer» E. | |
13. |
Which pyrimidine base contains an amino group at carbon 4? |
A. | Thymine |
B. | Cytosine |
C. | Adenine |
D. | Uracil |
Answer» C. Adenine | |
14. |
Thymidine |
A. | is replaced by uracil in RNA |
B. | can participate in hydrophobic interactions due to its methyl group |
C. | all of the above |
D. | normally forms two hydrogen bonds with adenosine |
Answer» D. normally forms two hydrogen bonds with adenosine | |
15. |
Which of the following is a purine? |
A. | Adenine |
B. | Cytosine |
C. | Uracil |
D. | Thymine |
Answer» C. Uracil | |
16. |
The most stabilizing force for nucleic acids is |
A. | electrostatic bond |
B. | hydrogen bonds |
C. | conformational entropy |
D. | Van der Waals |
Answer» B. hydrogen bonds | |
17. |
WHICH_OF_THESE_STATEMENTS_ARE_INCORRECT_ACCORDING_TO_CHARGAFF‚ÄÖ√Ñ√∂‚ÀÖ√Ë‚ÀÖ¬•S_RULES??$# |
A. | The molar ratio of A to T or C to G = 1 |
B. | The sum of purine = sum of pyrimidine |
C. | The % C+G ≠ % A+T |
D. | The composition of DNA remains the same in all the species |
Answer» E. | |
18. |
A purified DNA sample of leaf contains 20.0 mole of guanine. Calculate the approximate percentage of purine residues?$ |
A. | 30% |
B. | 40% |
C. | 60% |
D. | 20% |
Answer» B. 40% | |
19. |
Which bond is used to stabilize the double helix of DNA? |
A. | Hydrophobic bond |
B. | Hydrogen bond |
C. | Covalent bond |
D. | Ionic bond |
Answer» C. Covalent bond | |
20. |
The primary structure of DNA and RNA proceeds in which direction? |
A. | 3’ —–> 5҆’ |
B. | 5’ —–> 3’ |
C. | 4’ —–> 6’ |
D. | 3’ —–> 6’ |
Answer» C. 4‚Äö√Ñ√∂‚àö√ë‚àö¬• ‚Äö√Ñ√∂‚àö√ë‚àö√Ü‚Äö√Ñ√∂‚àö√ë‚àö¬®> 6‚Äö√Ñ√∂‚àö√ë‚àö¬• | |
21. |
What is the energy currency of the living cell? |
A. | GTP |
B. | NADH |
C. | FADH |
D. | ATP |
Answer» E. | |
22. |
Which of these statements are TRUE for a glycosidic bond? |
A. | The bond between sugar and the nitrogenous base |
B. | The bond between the two sugar residues |
C. | The bond between sugar and phosphate |
D. | The bond between base and phosphate |
Answer» B. The bond between the two sugar residues | |
23. |
Deoxyribose sugar is found in DNA. |
A. | True |
B. | False |
Answer» B. False | |
24. |
Name those purine bases which are commonly found in DNA and RNA? |
A. | Adenine and guanine |
B. | Cytosine and thymine |
C. | Adenine and thymine |
D. | Cytosine and guanine |
Answer» B. Cytosine and thymine | |
25. |
Name the pyrimidine base which is found in RNA but not in DNA? |
A. | Thymine |
B. | Uracil |
C. | Adenine |
D. | Guanine |
Answer» C. Adenine | |
26. |
Who discovered nucleic acid? |
A. | Watson and Crick |
B. | Griffith |
C. | Friedrich Miescher |
D. | Walter Gilbert |
Answer» D. Walter Gilbert | |
27. |
The monomeric unit of nucleic acid are called ___________ |
A. | Nucleotides |
B. | Nucleosides |
C. | Pyrimidines |
D. | Purines |
Answer» B. Nucleosides | |