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2.2.3Structure and Functions in Living Organisms: Part 1

Importance of Cell Differentiation

5 min read 5 parts Lesson 5 of 36 Unit quiz

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Section 1 of 5What Differentiation Means

2.2.3 Importance of Cell Differentiation
Differentiation
  • Differentiation is the process by which an unspecialised cell changes to become a specialised cell with a particular job.
Genes
  • All cells in an organism carry the same genes, but each type of cell uses only the genes it needs.
Stem cells
  • Unspecialised stem cells divide and their daughter cells can differentiate into different cell types.
Structure and function
  • A specialised cell has features that suit its function, such as extra organelles or a special shape.

Section 2 of 5Examples of Specialised Cells

Examples of Specialised Cells
Red blood cell
  • The biconcave shape and lack of a nucleus give room for haemoglobin and a large surface area to carry oxygen.
Root hair cell
  • A long projection greatly increases the surface area for absorbing water and mineral ions from soil.
Palisade cell
  • Many chloroplasts and a tall shape near the leaf surface allow plenty of photosynthesis.
Sperm cell
  • A tail allows the cell to swim, and many mitochondria provide the energy for movement.
Nerve cell
  • A very long, thin shape carries electrical impulses over long distances in the body.

Section 3 of 5From Cells to Organs

1
A specialised cell does one job well, such as muscle cells contracting to cause movement.
2
Many similar cells working together form a tissue, for example muscle tissue.
3
Different tissues combine in an organ, such as the stomach, which contains muscle, glandular and epithelial tissue.
4
Several organs work together in an organ system, such as the digestive system.
5
The organ systems together make up the whole organism, whose cells depend on each other.

Section 4 of 5Why Differentiation Matters

Division of labour
  • Different cells doing different jobs lets a large organism carry out many processes at the same time.
Efficiency
  • Cells that are specialised carry out their function more effectively than unspecialised cells could.
Size
  • Multicellular organisms can grow large because specialised transport and exchange systems supply all their cells.
Repair
  • Stem cells can differentiate to replace damaged or dead cells, such as skin cells.

Section 5 of 5Exam Checklist & Tips

2.2.3 – Key Points for the Exam

  • Cell differentiation The process by which a cell becomes specialised for a particular function.
  • Specialised cell A cell with a structure that is adapted to carry out a specific job.
  • Tissue A group of similar cells working together to carry out a function.
  • Organ A structure made of different tissues that work together to carry out a function.
  • Stem cell An unspecialised cell that can divide and differentiate into other cell types.

Common Mistakes

  • Saying cells in the same organism have different genes; they have the same genes but use different ones.
  • Describing an adaptation without linking it to the function, such as just stating the cell has a tail.
  • Confusing tissues and organs; an organ contains several tissues.
  • Writing that red blood cells have a nucleus; mature mammalian red blood cells do not.
Cambridge 9700 AS Biology Core Formula

Magnification Triangle & Unit Conversion

Formula: M = I / A  ⇔  A = I / M  ⇔  I = M × A

Units: 1 mm = 1,000 μm = 1,000,000 nm.
Rule: Convert Image size (ruler mm) to μm by ×1,000 before dividing by Actual size.