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First teaching 2023

First exams 2025

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Prokaryotic v Eukaryotic Cells (CIE AS Biology)

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Naomi H

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Naomi H

Last updated

Structural Features of Typical Prokaryotic Cells

  • Animal and plant cells are eukaryotic cells, whereas bacterial cells are prokaryotic
  • Prokaryotes have a cellular structure that is distinct from eukaryotes:
    • Their genetic material is free in the cytoplasm and is circular
      • Eukaryotic genetic material is packaged as linear chromosomes in the nucleus
    • Prokaryotes lack membrane-bound organelles
      • This means that they do not have any internal structures surrounded by membrane, e.g. a nucleus or mitochondria
    • They are many times smaller than eukaryotic cells
      • Prokaryotic cells are usually 1-5 μm in diameter, while eukaryotic plant cells can be 10-100 μm across
    • Their ribosomes are structurally smaller (70 S) in comparison to those found in eukaryotic cells (80 S)
    • Their cell walls are made of peptidoglycan rather than cellulose or chitin
  • Prokaryotes are always unicellular, while eukaryotic animal and plant cells can function together in multicellular organisms

prokaryotic-cell-structure

Prokaryotic cells have no internal membrane-bound structures, and are smaller than eukaryotic cells

Prokaryotic v Eukaryotic Cell Structures

Comparing prokaryote and eukaryote cell structure table

Feature Prokaryotes Eukaryotes
Size 0.5-5 μm Up to 100 μm
Genetic material

Circular chromosome in the cytoplasm

Not associated with proteins

Linear chromosomes in the nucleus

Associated with histone proteins
Cell division

Binary fission

No spindle fibres involved

Mitosis or meiosis

Chromosomes are separated by spindle fibres
Ribosomes 70S 80S
Organelles No membrane-bound organelles Multiple membrane-bound organelles, e.g. a nucleus, mitochondria, chloroplasts
Cell wall Made of peptidoglycan Made of cellulose in plants, or chitin in fungi

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Naomi H

Author: Naomi H

Expertise: Biology

Naomi graduated from the University of Oxford with a degree in Biological Sciences. She has 8 years of classroom experience teaching Key Stage 3 up to A-Level biology, and is currently a tutor and A-Level examiner. Naomi especially enjoys creating resources that enable students to build a solid understanding of subject content, while also connecting their knowledge with biology’s exciting, real-world applications.