Chapter 10 of Class 11 Biology is Cell Cycle and Cell Division. It covers the phases of the cell cycle, mitosis, and meiosis, and their significance in growth, repair, and reproduction. These Class 11 Biology Chapter 10 solutions are also useful as quick revision notes before exams.
The Cell Cycle
The sequence of events by which a cell duplicates its contents and divides into two. Consists of interphase (G1, S, G2 phases — growth, DNA replication, preparation) and M phase (mitosis, actual division).
Interphase
G1 phase: cell growth, metabolically active, no DNA synthesis. S phase: DNA replication occurs, chromosome number remains same but DNA content doubles. G2 phase: further growth, preparation for mitosis (protein synthesis for spindle formation).
Mitosis
Division producing two genetically identical diploid daughter cells. Phases: prophase (chromosome condensation), metaphase (chromosomes align at equator), anaphase (sister chromatids separate to opposite poles), telophase (nuclear envelope reforms, cytokinesis follows). Important for growth and repair.
Meiosis
Reductional division producing four genetically variable haploid daughter cells from one diploid cell, essential for sexual reproduction. Consists of two divisions: Meiosis I (reductional, homologous chromosomes separate, crossing over occurs in prophase I) and Meiosis II (equational, similar to mitosis, sister chromatids separate).
Significance of Meiosis
Maintains constant chromosome number across generations (halves it, restored at fertilization) and generates genetic variation through crossing over (prophase I) and independent assortment.
Class 11 Biology Chapter 10 – Notes and Extra Questions
Along with these NCERT Solutions, students can also use the Class 11 Biology Chapter 10 Extra Questions and Class 11 Biology Chapter 10 Revision Notes for quick revision and extra practice.
