 All living things are made up of cells.  Cells are the smallest working units of all living things.  All cells come from preexisting cells through cell division.

A cell is the smallest unit that is capable of performing life functions.

Amoeba Proteus Plant Stem Red Blood Cell Nerve Cell Bacteria

Prokaryotic Eukaryotic

 Do not have structures surrounded by membranes  Few internal structures  One-celled organisms, Bacteria

 Contain organelles surrounded by membranes  Most living organisms PlantAnimal

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Organelles

 Outer membrane of cell that controls movement in and out of the cell  It is semi-permeable i.e. let some substances to pass through while stops others.

 Most commonly found in plant cells & bacteria  Made of a rigid material called cellulose  Supports & protects the cells

 Directs cell activities  Separated from cytoplasm by nuclear membrane  Contains genetic material - DNA

 In nucleus  Made of DNA  Contain instructions for traits & characteristics

 Gel-like mixture  Surrounded by cell membrane  Site for chemical reactions such as respiration

 Membrane-bound sacs for storage and digestion  Contains water solution  Help plants maintain shape  Some animal cells may have tiny vacuoles

 Usually found in plant cells  Contains green chlorophyll  Where photosynthesis takes place

 Cells with modified or improved designs  To enable them to perform a specific function

 The following types of animal cells have adapted in order to better perform their function.  White blood cells  Red blood cells  Nerve cells  Ciliated epithelial cells  Smooth muscle cells

 The following plant cells have adapted to do their job more efficiently  Root hair cells  Palisade mesophyll cells  Spongy mesophyll cells

 A group of identical cells performing the same function form a tissue  Tissues of several type work together to make an organ  Some organs and tissues form organ systems  All organ systems work in harmony for the well being of the organism