D2.1.1—Generation of new cells
New cells arise through division of existing cells, allowing multicellular growth, tissue repair, cell replacement and reproduction across living organisms.
- Syllabus
- First assessment 2025
- Objective
- D2.1.1
- Level
- HL
Cell Division Makes New Cells
In every living organism, cell division generates new cells when one parent cell divides to produce two daughter cells.
Producing daughter cells allows an organism to grow, replace worn cells, repair damaged tissue or reproduce asexually. The genetic material must be distributed before the cytoplasm separates so both daughters can function.
A skin cell can divide into two daughter cells that replace cells lost from the surface, while a single-celled organism can divide to produce two organisms.
The parent cell is sometimes called a mother cell, but this does not imply sex or fertilization. Cell division means generation of daughter cells, not growth of one cell alone.
Generation of new cells
Assessment in practice
1 marksHow it is assessed
This objective is assessed through multiple choice, commonly using Identify.
Command terms
Identify
What earns marks
Build the answer around this relationship: Cells arise from pre-existing cells by cell division.
Representative question
Question 1
[Maximum number: 1]
Which process contributes to growth of a multicellular body?
A
Exocytosis
B
Meiosis
C
Mitosis
D
Osmosis
C
Core Cell Division
- Cell division produces daughter cells for growth, repair or reproduction; cytokinesis divides cytoplasm by a contractile ring in animals or a cell plate in plants.
- DNA replication creates sister chromatids joined at centromeres before nuclear division.
- Mitosis preserves chromosome number: chromosomes condense, align, sister chromatids separate and nuclei reform, producing genetically identical nuclei.
- Meiosis follows one replication with two divisions: homologous chromosomes separate in meiosis I and sister chromatids in meiosis II, producing haploid cells.
- Crossing over, independent orientation and random fertilization generate allele combinations.
- Non-disjunction is failed chromosome separation and can produce aneuploid cells, including trisomy 21.
- Identify stages in micrographs from chromosome condensation, equatorial alignment, separation and nuclear-envelope cues.
Concept essentials
- Cells arise from pre-existing cells by cell division.
- Mitosis contributes to growth in multicellular organisms.
- Cell division can replace or repair damaged tissues.
- Daughter cells inherit genetic information from the parent cell.