Every living organism grows, repairs itself, and reproduces through the amazing process of cell division. This chapter, Cell Cycle, explains how a single cell prepares to divide, grows, and produces new cells. You will learn about mitosis, which helps in growth and repair, and meiosis, which is essential for producing gametes and ensuring genetic diversity.
We will also explore the differences between mitosis and meiosis, so you can understand how each process plays a unique role in life. By the end of this chapter, you will know how cells manage their life cycle and why this process is crucial for all living things.
Class 9 Biology Chapter 4 MCQs – Cell Cycle
1. In which phase of the cell cycle does growth occur in the cell?
a) M phase
b) G1 phase ✅
c) G2 phase
d) S phase
2. Which event is unique to meiosis but not mitosis?
a) DNA replication
b) Chromosome alignment
c) Crossing over ✅
d) Nuclear division
3. Which phase of the cell cycle takes about 90% of the total time?
a) G1 Phase
b) Mitosis
c) Interphase ✅
d) S Phase
4. Mitosis occurs in which type of cells?
a) Germ cells
b) Somatic cells ✅
c) Red blood cells
d) Prokaryotic cells
5. The main role of mitosis in growth is:
a) Production of gametes
b) Increase in cell size
c) Production of identical cells ✅
d) DNA mutation
6. Meiosis produces how many daughter cells?
a) 2
b) 3
c) 4 ✅
d) 5
7. What occurs during the G2 phase of the cell cycle?
a) Cell stops dividing permanently
b) DNA is copied
c) Preparation for mitosis and DNA damage check ✅
d) Formation of chromatin
Class 9 Biology Chapter 4 Short Questions – Cell Cycle
1. What is the difference between prophase of mitosis and prophase-I of meiosis-I?
Answer:
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Mitotic prophase: Homologous chromosomes do not pair and no crossing over occurs.
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Prophase-I of meiosis-I: Homologous chromosomes pair up, and crossing over occurs, which increases genetic variation in gametes.
2. What is the main purpose of the S phase in the cell cycle?
Answer:
The main purpose of the S phase is to duplicate the DNA, so that each chromosome consists of two identical sister chromatids. This ensures that when the cell divides, both daughter cells receive the exact genetic information.
3. Discuss the significance of the G1, S, and G2 phases in preparing the cell for division.
Answer:
The G1, S, and G2 phases are part of the interphase and play a crucial role in preparing the cell for division:
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G1 Phase: The cell grows, synthesizes proteins and organelles, and prepares for DNA replication. This ensures the cell has enough resources to divide successfully.
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S Phase: DNA replication occurs, producing two identical sister chromatids for each chromosome. This guarantees that each daughter cell will receive a complete set of genetic material.
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G2 Phase: The cell checks for DNA errors and ensures it has all the proteins and structures needed for mitosis.
Significance: These phases are essential because they ensure the cell is healthy, has enough resources, and its genetic material is accurately duplicated before division, which is crucial for proper growth, repair, and reproduction.
📥 Download Chapter 4 Notes – Cell Cycle
Get Class 9 Biology Chapter 4 complete notes for the 2026 new syllabus, including:
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Cell Cycle
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Mitosis
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Meiosis
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Comparison between Mitosis and Meiosis
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Important MCQs, Short & Long Questions
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