Edexcel IGCSE Biology 复习笔记 2.1.1 Levels of Organisation

Edexcel IGCSE Biology 复习笔记 2.1.1 Levels of Organisation

Cells, Tissues, Organs & Organ Systems

 

  • Cells are the basic building blocks of all living organisms
  • Unicellular organisms are made from one cell, whereas multicellular organisms are made up of collections of cells
  • In complex multicellular organisms:
    • Cells are specialised to carry out particular functions
    • These specialised cells form tissues
    • The tissues form organs
    • The organs form organ systems

     

  • In humans, the digestive system (provides the body with nutrients) and the respiratory system (provides the body with oxygen and removes carbon dioxide) are examples of organ systems that provide dissolved materials that need to be moved quickly around the body in the blood by the circulatory system

 

 

Different-levels-of-organisation-in-organisms-1Different-levels-of-organisation-in-organisms-2

 

Multicellular organisms have many levels of organisation

 

 

 

Different Levels of Organisation Table

 

Different-Levels-of-Organisation-Table

 

 

 

Examples of Organ Systems in Animals & Plants Table

Tissue-Examples-table

 

 

Identifying levels of organisation

  • 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

 

Typical levels of organisation question. The answer is B: 1 is the leaf organ, 2 is a palisade mesophyll cell and 3 is the spongy mesophyll layer.

转载自savemyexam

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