2.1 describe the levels of organisation within organisms: organelles, cells, tissues, organs and systems.

Organelles à  Cells à Tissues à Organs à Organ systems

Organelles – Specialised structures that carry out a particular function within a cell (intracellular). They are made out of highly organized structures of molecules.

 

     E.g. Chloroplast – absorbs light to complete photosynthesis. 

Cells- Basic structural and functional unit from which organisms are made off, also known as the “building blocks of life”. Cells are made out of organelles.

Tissue – Group of specialized cells with similar structures and the same origin, which work together to carry out a specific function.

Organ – Structure made out of a group of tissues, which work together and are adapted to perform a specific function in an organism.

 

     E.g. The heart, its function is to pump blood around the body

Organ system – Group of several organs (with related functions) which work together to carry out a specific function.

 

    E.g.  The circulatory system includes blood vessels and the heart