Topic Three: The Cell and its structures   Multi – cellular - organisms that have two or more cells. Uni – cellular - organisms that have only one cell. Ex. Euglena, Paramecium, Diatoms. Most make their food by photosynthesis

Cell Parts All structures inside a cell, (animal or plant), are called organelles.   Cell Structures (Animal and Plant) Cell Membrane Surrounds the cell Controls the movement of the substances Cytoplasm Like jelly, constantly moving Moves oxygen and food to different parts of the cell

Nucleus Easiest to see under a microscope Controls the cell Holds chromosomes, (genetic material) Surrounded by a nuclear membrane   Vacuoles Inside the cytoplasm Store extra food, wastes, and other substances

Cell Structures (Plant ONLY)   Cell Wall Made up of cellulose Supports the cell shape Chloroplasts Where photosynthesis takes place Contain chlorophyll which absorbs sunlight

Cell Size & Function   Cells are small because they need a constant supply of energy, (food/oxygen), to survive. The bigger the cell the more energy required. For an organism to grow, the cells stay the same size just increase in number, (more are produced).