Why do cells divide?

Cell division  happens in all organisms.  Cell division takes place for  different reasons.  For  example, single-celled organisms reproduce  through  cell division.   In  multicellular organisms, cell division is involved in growth, development, and  repair, as well as reproduction.

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Reproduction
Cell division is important for asexual
reproduction, which involves only one parent organism.  In single-celled organisms, the parent divides in two, producing two identical offspring.  
     In single-celled and some multicellular organisms, offspring result when a parent organism buds, producing offspring.
     In multicellular organisms,  reproduction by cell division can include plant structures such as runners and plantlet.

Growth and Repair
One characteristic of all living things is that they grow.  You are probably bigger this year than you were last year.  Your body is made up of cells.  Although cells themselves grow, most growth in multicellular organisms happens because cell division produces
new cells.
    Cell division also produces cells for repair.  If you cut your hand or break a bone, the damages cells are replaced by new cells that form during cell division.

Reading Check.  Look at the pictures below.  Read the questions by each picture BEFORE answering the question.

Take a look at the paramecium.  What is the role of cell division for  this organism?  Is it reproduction or growth and repair?

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Take a look at the Northern Pacific starfish.  What is the role of cell division for this organism?  Is it reproduction or growth and repair?

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