What we will learn about..

​- unicellular vs multicellular organisms

​- differentiated cells

​- organism structure

​Unicellular vs Multicellular?

• ​Unicellular = one cell

• ​Multicellular = many cells

• ​Many unicellular organisms have a different structure than plant or animal cells

• ​They are often MUCH smaller, and sometimes do not contain a nucleus, mitochondria, or other organelles

• ​They have everything they need to survive in ONE CELL

​Multicellular Organisms

• ​All started out as one cell

• ​As you grow, your cells DIFFERENTIATE to become different types of cells to carry out all the functions of the organism

  • ​e.g. brain, skin, heart cells. These are all different, and carry out different function to keep the organism alive

​Advantages and Disadvantages:

• ​MC takes more energy to be alive and to grow

• ​UC is quick to reproduce

• ​MC are more diverse

• ​MC are more resilient (i.e. one cell can die, but the whole organism if OK)

• Can you think of anymore?

​Structure of MC Organisms

• ​Same type of specialised cell --> Tissue --> Organ --> System --> Organism

• ​Example:

  • ​Brain cells --> Brain tissue (grey matter) --> Brain --> Nervous System --> Organism