1. During which phase of the cell cycle does DNA replication occur?
a. G1 phase
b. S phase
c. G2 phase
d. M phase
Answer: b. S phase
2. What is the correct sequence of stages in mitosis?
a. Prophase, Metaphase, Anaphase, Telophase
b. Metaphase, Prophase, Anaphase, Telophase
c. Telophase, Anaphase, Prophase, Metaphase
d. Anaphase, Telophase, Metaphase, Prophase
Answer: a. Prophase, Metaphase, Anaphase, Telophase
3. Which of the following is a characteristic of cytokinesis in plant cells?
a. Formation of a cleavage furrow
b. Pinching of the cell membrane
c. Formation of a cell plate
d. No cytokinesis in plant cells
Answer: c. Formation of a cell plate
4. What is the significance of meiosis in the cell cycle?
a. Production of genetically identical cells
b. Repair of damaged cells
c. Formation of gametes
d. Growth and development of the organism
Answer: c. Formation of gametes
5. Which checkpoint in the cell cycle assesses whether DNA has been replicated properly?
a. G1 checkpoint
b. S checkpoint
c. G2 checkpoint
d. M checkpoint
Answer: c. G2 checkpoint
6. What is the purpose of the G1 checkpoint in the cell cycle?
a. Check for DNA damage and repair
b. Assess DNA replication
c. Ensure proper chromosome alignment
d. Verify spindle fiber formation
Answer: a. Check for DNA damage and repair
7. Which enzyme is responsible for unwinding the DNA double helix during DNA replication?
a. DNA ligase
b. DNA polymerase
c. Helicase
d. RNA polymerase
Answer: c. Helicase
8. What is the end result of mitosis in animal cells?
a. Two diploid cells
b. Four haploid cells
c. Two identical diploid cells
d. Two genetically different haploid cells
Answer: a. Two diploid cells
9. In meiosis, homologous chromosomes separate during which stage?
a. Prophase I
b. Metaphase I
c. Anaphase I
d. Telophase I
Answer: c. Anaphase I
10. Which phase of the cell cycle is characterized by rapid cell growth and preparation for DNA replication?
a. G1 phase
b. S phase
c. G2 phase
d. M phase
Answer: a. G1 phase
11. What is the correct order of phases during interphase in the cell cycle?
a. G1, S, G2
b. G2, S, G1
c. S, G1, G2
d. G1, G2, S
Answer: a. G1, S, G2
12. During which phase of mitosis do chromosomes align at the equatorial plane of the cell?
a. Prophase
b. Metaphase
c. Anaphase
d. Telophase
Answer: b. Metaphase
13. What is the primary function of the spindle fibers during mitosis?
a. Separation of chromatids
b. DNA replication
c. Formation of the cell plate
d. Synthesis of proteins
Answer: a. Separation of chromatids
14. In meiosis, what is the end result of the second division (Meiosis II)?
a. Four haploid cells
b. Two diploid cells
c. Two haploid cells
d. Four diploid cells
Answer: a. Four haploid cells
15. What is the role of the centrosome in cell division?
a. Formation of the cell plate
b. Synthesis of DNA
c. Organization of spindle fibers
d. Separation of chromatids
Answer: c. Organization of spindle fibers
16. Which phase of the cell cycle is known as the “resting phase”?
a. G1 phase
b. S phase
c. G2 phase
d. M phase
Answer: a. G1 phase
17. What is the significance of crossing over during meiosis?
a. Formation of identical daughter cells
b. Introduction of genetic variation
c. Prevention of DNA replication errors
d. Regulation of cell cycle checkpoints
Answer: b. Introduction of genetic variation
18. During cytokinesis in animal cells, what structure is responsible for dividing the cytoplasm?
a. Cell plate
b. Cleavage furrow
c. Centrosome
d. Spindle fibers
Answer: b. Cleavage furrow
19. In meiosis, when does recombination (crossing over) occur?
a. Prophase I
b. Metaphase I
c. Anaphase I
d. Telophase I
Answer: a. Prophase I
20. What is the primary function of the G2 checkpoint in the cell cycle?
a. Check for DNA damage and repair
b. Assess DNA replication
c. Ensure proper chromosome alignment
d. Verify cell size and organelle content
Answer: d. Verify cell size and organelle content
21. The process of appearance of recombination nodules occurs at which sub-stage of prophase I in meiosis?
1. Diakinesis
2. Zygotene
3. Pachytene
4. Diplotene
Answer – 3, Pachytene
22. Among eukaryotes, replication of DNA takes place in
1. G2 Phase
2. M phase
3. S phase
4. G1 phase
Answer – 3, S phase
23. Which one of the following never occurs during mitotic cell division?
1. Coiling and condensation chromatids
2. Spindle fibers attach to Kinetochores of chromosomes
3. Movement of centrioles toward opposite poles
4. The pairing of homologous chromosomes
Answer – 4, Pairing of homologous chromosomes
24. Regarding meiosis, which statement is incorrect?
1. Four haploid cells form at the end of meiosis-II
2. In meiosis, there are two stages: meiosis I and II
3. DNA replication occurs in the S phase of meiosis-II
4. The pairing of homologous and recombination chromosomes occurs during meiosis-1
Answer – 3, DNA replication occurs in the S phase of meiosis -II
25. When do the chromosomes pair during meiosis I?
1. Leptotene
2. Zygotene
3. Pachytene
4. Diplotene
Answer – 2, Zygotene
26. What is true about the mitotic spindle?
1. It is composed of actin and myosin microfilaments.
2. It includes the kinetochore at the metaphase plate.
3. It is composed of microtubules, which separate chromosomes at opposite poles of the cell.
4. It originates only from centrioles of centrioles.
Answer- 3, It is composed of microtubules, which separate chromosomes at opposite poles of the cell.
27. The synapsis occurs between
1. male gamete and female gamete
2. mRNA and ribosomes
3. spindle fiber and centromere
4. two homologous chromosomes
Answer – 4, two homologous chromosomes
28. The appearance of recombination nodules on homologous chromosomes during meiosis characterizes:
1. Personalization
2. Synaptonemal complex
3. Bivalent
4. Sites at which crossing over occurs
Answer – 4, Sites at which crossing over occurs
29. Where does the synaptonemal complex appear?
1. Between homologous chromosomes
2. In the zygotene stage
3. Composed of DNA + protein
4. All the above
Answer – 4, All of the above
30. Which of the following precedes nuclear envelope reformation during the M phase of the cell cycle?
1. Chromosome decondensation and reassembly of the nuclear lamina
2. Transcription from chromosomes and nuclear leaf recombination
3. Contraction ring formation and phragmoplast. formation
4. Contraction ring formation and transcription from chromosomes.
Answer – 1, Decondensation from chromosomes and reassembly of the nuclear lamina
31. As there occurs more and more condensation of chromatin during cell division, there occurs
1. Increase in heterochromatin
2. Increase in euchromatin
3. Differentiation of heterochromatin and euchromatin decreases
4. Differentiation of heterochromatin and euchromatin increases
Answer- 4, Differentiation of heterochromatin and euchromatin increases
32. If a diploid cell is treated with colchicine, it becomes.
1. triploid
2. tetraploid
3. diploid
4. Monoploid
Answer – 2, tetraploid
33. What results in the formation of chiasmata?
1. Exchange of parts of paired homologous chromosome
2. Exchange of part of unpaired non-homologous chromosome
3. Duplication of parts of paired homologous chromosome
4. Loss of parts of unpaired non-homologous chromosome
Answer – 1, Exchange of parts of paired homologous chromosome
34. During mitosis ER and nucleolus begin to disappear at.
1. late prophase
2. early metaphase
3. late metaphase
4. early prophase
Answer – 4, early prophase
35. The stage which serves as a connecting link between meiosis 1 and meiosis 2
1. Interphase
2. Interphase
3. Interkinesis
4. None of the above
Answer- 3, Interkinesis
36. ________ is the best stage to observe the shape, size, and number of chromosomes
1. interphase
2. metaphase
3. prophase
4. Telophase
Answer – 2, Metaphase