Rucete ✏ Campbell Biology In a Nutshell
Unit 2 THE CELL — Concept 12.1 Most Cell Division Results in Genetically Identical Daughter Cells
Cell division is a fundamental biological process that ensures the continuity of life by producing genetically identical daughter cells through precise DNA replication and distribution.
Functions of Cell Division
Enables reproduction in unicellular organisms
Supports growth and development in multicellular organisms
Responsible for tissue renewal and repair (e.g., skin, blood cells)
Produces two genetically identical daughter cells from one parent cell
Genome and Chromosomes
A cell’s total DNA is called its genome
Eukaryotic genomes are organized into multiple linear chromosomes
DNA is packaged with proteins into chromatin
Chromatin condenses into visible chromosomes during division
Chromosome Structure
Duplicated chromosomes consist of two sister chromatids joined at the centromere
Chromatids contain identical DNA molecules
Once separated during division, chromatids become individual chromosomes
Ensures each daughter cell receives a complete set of chromosomes
Cell Cycle Phases
The cell cycle includes interphase and the mitotic (M) phase
Interphase (90% of the cycle) has three phases:
G₁: cell growth
S: DNA replication
G₂: preparation for division
M phase includes mitosis (division of nucleus) and cytokinesis (division of cytoplasm)
Mitosis and Meiosis
Mitosis produces somatic cells with identical DNA
Meiosis produces gametes with half the number of chromosomes
Humans: somatic cells have 46 chromosomes; gametes have 23
Fertilization restores chromosome number and is followed by mitotic growth
In a Nutshell
Cell division creates two genetically identical daughter cells through a coordinated process of DNA replication, chromosome condensation, and distribution. This process supports growth, repair, and reproduction in living organisms.