NCERT Solutions for Class 11 Biology Chapter 10 – Cell Cycle and Cell Division
Chapter 10 Cell Cycle and Cell Division is arguably one of the most diagram-heavy and conceptually rich chapters in Class 11 Biology. Understanding how cells divide is not just important for exams — it is the fundamental process underlying growth, development, repair, and reproduction in all living organisms. Must check the CBSE resources and NCERT Solutions.
This chapter covers the complete sequence of events in a cell cycle, the stages of mitosis and meiosis, and the significance of each type of division. For NEET aspirants, questions from this chapter appear almost every year, making it non-negotiable in your preparation. The NCERT Solutions for Chapter 10 available on Myclass24 are crafted to guide students through each phase clearly — from the G1 phase of interphase to the final cytokinesis — with accurate, textbook-aligned answers. Whether you are struggling with the difference between mitosis and meiosis or trying to understand the significance of crossing over during prophase I, these solutions break down every concept in a simple, accessible manner for students across CBSE schools in India.
Download PDF – NCERT Solutions for Class 11 Biology Chapter 10 Cell Cycle and Cell Division
The cell cycle is the sequence of events by which a cell duplicates its genome and divides into two daughter cells. The total duration of the cell cycle varies among organisms — it is about 24 hours in human cells dividing under normal conditions. The cell cycle is divided into two main phases: Interphase and the Mitotic (M) phase. Check out NCERT Solutions for Class 11 Biology and NCERT Solutions for Class 11 for the rest of the chapters.
Interphase is the longest phase of the cell cycle, often called the resting phase, though the cell is far from resting. It is divided into G1 (first gap), S (synthesis), and G2 (second gap). During G1, the cell grows and prepares for DNA replication. During S phase, DNA synthesis (replication) occurs, and the DNA content doubles. During G2, the cell prepares for division and synthesizes proteins needed for mitosis. Some cells exit the cell cycle and enter a non-dividing state called G0 phase.
| Phase | Key Events | DNA Content |
| G1 Phase | Cell growth, protein synthesis | 2n (diploid) |
| S Phase | DNA replication | 2n → 4n |
| G2 Phase | Preparation for mitosis | 4n |
| Mitosis (M Phase) | Nuclear & cell division | 4n → 2n (each daughter) |
| G0 Phase | Non-dividing / quiescent state | 2n |
Mitosis is a type of cell division that produces two genetically identical daughter cells, each with the same number of chromosomes as the parent cell. Mitosis occurs in somatic (body) cells and is essential for growth, repair, and asexual reproduction. It has four stages: Prophase, Metaphase, Anaphase, and Telophase, followed by Cytokinesis.
During Prophase, chromosomes become visible as chromatin condenses. The mitotic spindle begins to form from the centrosomes. The nuclear envelope breaks down. During Metaphase, chromosomes align at the cell's equatorial plate (metaphase plate) and spindle fibers attach to centromeres. This is the best stage to count chromosomes. During Anaphase, sister chromatids separate and are pulled toward opposite poles by spindle fibers. During Telophase, the nuclear envelope reforms around each set of chromosomes, and chromosomes decondense. Cytokinesis then follows — in animal cells by cleavage furrow formation and in plant cells by cell plate formation.
Meiosis is a special type of cell division that produces four genetically different haploid cells from a single diploid cell. It occurs in gonads (testes and ovaries) and is essential for sexual reproduction. Meiosis consists of two successive divisions: Meiosis I (reductive division) and Meiosis II (equational division).
Meiosis I is the most complex phase. It includes Prophase I (leptotene, zygotene, pachytene, diplotene, diakinesis), during which homologous chromosomes undergo synapsis (pairing) and crossing over occurs at chiasmata. Crossing over is the exchange of genetic material between non-sister chromatids of homologous chromosomes, resulting in genetic recombination — a major source of genetic variation. By the end of Meiosis I, the chromosome number is halved.
| Feature | Mitosis | Meiosis |
| Occurs in | Somatic cells | Germ cells (gonads) |
| Number of divisions | One | Two (Meiosis I and II) |
| Daughter cells | 2 diploid cells | 4 haploid cells |
| Genetic identity | Identical to parent | Genetically different |
| Crossing over | Does not occur | Occurs in Prophase I |
| Chromosome number | Maintained (2n → 2n) | Halved (2n → n) |
| Purpose | Growth, repair, regeneration | Gamete formation |
| Synapsis | Does not occur | Occurs in Zygotene |
An important fact for NEET: during Meiosis I, homologous chromosomes separate (not sister chromatids), making it the reductional division. During Meiosis II, sister chromatids separate, similar to mitosis, making it equational division. The significance of meiosis lies in maintaining the chromosome number across generations and creating genetic diversity through crossing over and independent assortment. Check out NCERT Solutions for Class 11 Biology and NCERT Solutions for Class 11 for the rest of the chapters.
Regulation of the cell cycle is controlled by cyclins and cyclin-dependent kinases (CDKs). Checkpoints in the cell cycle (G1/S, G2/M, and spindle assembly checkpoint) ensure that conditions are appropriate before the cell progresses. Failure of these checkpoints can lead to uncontrolled division — the hallmark of cancer. Myclass24 NCERT Solutions for Chapter 10 cover all these points with clarity, helping students score well in both theory and diagram-based questions.