CIE IGCSE Biology: 复习笔记：2.1.2 Organisation of Cells

• The cells in your body need to be able to divide to help your body grow and repair itself
• Cells grow and divide over and over again
• New cells are produced by the division of existing cells

Specialised cells in animals

• Specialised cells are those which have developed certain characteristics in order to perform particular functions. These differences are controlled by genes in the nucleus
• Cells specialise by undergoing differentiation: this is a process by which cells develop the structure and characteristics needed to be able to carry out their functions

Specialised Cells in Animals Table

 Diagrams of specialised cells in animals:

Ciliated cell

Nerve cell

Red blood cells

Sperm cell

Egg cell

Examples of specialised cells in plants:

Diagrams of specialised cells in plants:

Root hair cell

Xylem structure

Palisade mesophyll cell

Levels of organisation

• Your syllabus states that you should be able to identify the different levels of organisation in drawings, diagrams and images of familiar material
• An example of this is shown in the exam question below:

Typical levels of organisation question