MCQOPTIONS
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MCQOPTIONS
This section includes 34 Mcqs, each offering curated multiple-choice questions to sharpen your Biology Mcqs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Chromosome is made of |
| A. | 2 chromatids +1 centromere +secondary constriction |
| B. | 1 chromated + 1 centromere + primary constriction |
| C. | 2 chromatids + 1 centromere + primary constriction |
| D. | 2 chromatids + 2 centromere + secondary constriction |
| Answer» B. 1 chromated + 1 centromere + primary constriction | |
| 2. |
Chromosomes are composed of |
| A. | 40% protein and 60% DNA |
| B. | 50% protein and 50% DNA |
| C. | 70% protein and 30% DNA |
| D. | 60% protein and 40% DNA |
| Answer» E. | |
| 3. |
A typical human chromosome contains _________ nucleotides in its DNA |
| A. | 240 million |
| B. | 140 million |
| C. | 150 million |
| D. | 160 million |
| Answer» C. 150 million | |
| 4. |
Histones have abundance of amino acids |
| A. | Valine and lysine |
| B. | Arginine and lysine |
| C. | Valine and arginine |
| D. | Histidione and threonine |
| Answer» C. Valine and arginine | |
| 5. |
A tortion of chromatin that is condensed only during cell division is |
| A. | Euchromatin |
| B. | Heterochromatin |
| C. | Biochromatin |
| D. | Nucleochromatin |
| Answer» B. Heterochromatin | |
| 6. |
Transfer of genetic material from one cell to another that can alter the genetic makeup of recipient cell is called |
| A. | Mutation |
| B. | Transuction |
| C. | Replication |
| D. | Variation |
| Answer» C. Replication | |
| 7. |
DNA contains |
| A. | Purines (A and G) pyrimidines (U and (c) |
| B. | Purines (T and (c) pyrimidines (A and G) |
| C. | Purines (A and (c) pyrimidines (U and G) |
| D. | Purines (A and G) pyrimidines (T and (c) |
| Answer» E. | |
| 8. |
In DNA |
| A. | A forms two bonds with T |
| B. | G forms three bonds with C |
| C. | A forms three bonds with T |
| D. | Both a and b |
| Answer» E. | |
| 9. |
DNA has a helical shape with the diameter of |
| A. | 3 nm |
| B. | 4 nm |
| C. | 2 nm |
| D. | 5 nm |
| Answer» D. 5 nm | |
| 10. |
In semi-conservative replication |
| A. | Sequence of original duplex is conserved after one round of replication |
| B. | Gererate DNA copies of entirely new molecules |
| C. | Parental DNA become completely dispersed |
| D. | Each strand of daughter molecules will be a mixture of old and new |
| Answer» B. Gererate DNA copies of entirely new molecules | |
| 11. |
The true E.Coli replicating enzyme is |
| A. | DNA polymerase I |
| B. | DNA polymerase II |
| C. | DNA polymerase III |
| D. | All of these |
| Answer» D. All of these | |
| 12. |
Rate of DNA replication by DNA polymerase is |
| A. | 2000 nucleotides / sec |
| B. | 1000 nucleotides / sec |
| C. | 150 nucleotides / sec |
| D. | 1050 nucleotides / sec |
| Answer» C. 150 nucleotides / sec | |
| 13. |
Sex chromosomes were 1 discovered in |
| A. | Man |
| B. | Pea plant |
| C. | Fruitfly |
| D. | None of these |
| Answer» D. None of these | |
| 14. |
Which is incorrect about nucleosome |
| A. | 2 turns of DNA coiled round histones |
| B. | 8 histones as acidic proteins |
| C. | 200 nucleotides in one nucleosome |
| D. | None of these |
| Answer» C. 200 nucleotides in one nucleosome | |
| 15. |
A sugarcane cell has _________ chromosomes. |
| A. | 20 |
| B. | 32 |
| C. | 40 |
| D. | 80 |
| Answer» E. | |
| 16. |
Centromere represents |
| A. | Primary constriction |
| B. | Secondary constriction |
| C. | Tertiary constriction |
| D. | Quaternary constriction |
| Answer» B. Secondary constriction | |
| 17. |
Wich of the following cal kill mice if injected separately? |
| A. | Live R type pneumococcus |
| B. | Heat killed R type pneumococcus |
| C. | Live S type pneumococcus |
| D. | Heat killed S type pneumococcus |
| Answer» D. Heat killed S type pneumococcus | |
| 18. |
X-Ray diffraction pattern of DNA was prepared by |
| A. | Rosalind Franklin |
| B. | Maurice Wilkins |
| C. | Watson |
| D. | Crick |
| Answer» B. Maurice Wilkins | |
| 19. |
In sickle cell Hb, which chain is affected? |
| A. | Alpha chain |
| B. | Beta Chain |
| C. | Both of these |
| D. | None of these |
| Answer» C. Both of these | |
| 20. |
The length of okazaki fragments in eukayotes is |
| A. | 150--250 nucleotides long |
| B. | 200-300 nucleotides |
| C. | 1000-2000 nucleotdes |
| D. | 100-200 nucleotides |
| Answer» E. | |
| 21. |
Central dogma is |
| A. | Transfer of information from DNA to mRNA |
| B. | Basic mechanism of reading and expressing genes |
| C. | Transfer of information from RNA to proteins |
| D. | Synthesis of all three types of RNA |
| Answer» C. Transfer of information from RNA to proteins | |
| 22. |
The sequence of nucleotides that determines the amino acid sequence of a protein is |
| A. | Chromosome |
| B. | DNA |
| C. | RNA |
| D. | Gene |
| Answer» E. | |
| 23. |
In prokaryotes there are |
| A. | Three types of DNA polymerases |
| B. | One type of RNA polymerase |
| C. | Three types of RNA polymerase |
| D. | Both a and b |
| Answer» E. | |
| 24. |
Which 3 codons are nonsense codons? |
| A. | UAA,UAU,UUA |
| B. | UGA,UAG,UAA |
| C. | UGG,UGA,UAU |
| D. | UGG,UAA,UAG |
| Answer» C. UGG,UGA,UAU | |
| 25. |
In eukaryotes newly synthesized mRNA |
| A. | Travels a large distance from nucleus to cytoplasm |
| B. | Is directly released into the cytoplasm |
| C. | Contains a cap and tail |
| D. | Both a and c |
| Answer» E. | |
| 26. |
Human cell contains ______ different kinds of tRNA molecules |
| A. | 25 |
| B. | 35 |
| C. | 45 |
| D. | 15 |
| Answer» D. 15 | |
| 27. |
In mitochondria UGA is/specifies as |
| A. | Stop codon |
| B. | Tryptophan |
| C. | Initiation codon |
| D. | Methionine |
| Answer» C. Initiation codon | |
| 28. |
Methionine is specified by |
| A. | Stop codon |
| B. | AUG |
| C. | Start codon |
| D. | Both b and c |
| Answer» E. | |
| 29. |
Three nucleotide sequence on tRNA that specifies an amino acis is |
| A. | Codon |
| B. | Anticodon |
| C. | Nonsense codon |
| D. | Genetic code |
| Answer» C. Nonsense codon | |
| 30. |
Initiation complex in translation is composed of |
| A. | Ribosome and aminoacyl-tRNA |
| B. | Ribosome and tRNA |
| C. | TRNA and aminoacyl-tRNA |
| D. | None of these |
| Answer» B. Ribosome and tRNA | |
| 31. |
Point mutations are represented as |
| A. | Presence of an extra chromosome |
| B. | Loss of chromosome |
| C. | Alteration in sequence of DNA nucleotide |
| D. | Insertions and inversion of genes |
| Answer» D. Insertions and inversion of genes | |
| 32. |
Strand of DNA which is not transcribed is called |
| A. | Antisense |
| B. | Template |
| C. | Coding |
| D. | None of these |
| Answer» D. None of these | |
| 33. |
Phenylketonuria is due to deficiency of |
| A. | Phenylalnine |
| B. | Phenylalanine hydroxylase |
| C. | Phenylene |
| D. | All of these |
| Answer» C. Phenylene | |
| 34. |
Molecular basis of sickle cell anaemia was found by |
| A. | F. Sanger |
| B. | Beadle and Tatum |
| C. | Vernone Ingram |
| D. | Mendal |
| Answer» D. Mendal | |