Nucleus

Vacuoles

Ribosomes

Lysosomes

Endoplasmic Reticulum

Golgi apparatus

Mitochondria

Plasma membrane

Cytoplasm

Head Office

Warehouse

Machines

Garbage cans

Assembly workers

Shipping Department

Generators

Walls, doors, security

Pillars, floor, stairs

IF A CELL WERE A TOY COMPANY…

Different Cells

                       

                      

The one-celled organism 

amoeba proteus

A single-celled bacteria 

of the type: E. coli

A human red blood cell A plant cell from the leaf 

of a poplar tree

• Understand cell division in plants and animals.

• Be able to identify the stages of mitosis.

KEY TERMS

Reproduction Chromosomes

Mitosis Division

Cell cycle Interphase Prophase

Metaphase Anaphase Telophase

Functions of Cell Division

1. Healing and tissue repair-You replace 25 millions old cells each second.

2. Growth- An increase in the number of cells. 3. Reproduction of organisms- All organisms multiply and spread.

Any new cell come from existing cells by a process of reproduction.

A cell’s life is a sequence of steps called the cell cycle.

Cell cycle has two parts:

1. Interphase

2. Division phase

Interphase

• Rapid growth / repair – preparation for division.• Chromosomes (blueprints) must be copied.• Longest phase.

2. Cytokinesis - divide cytoplasm and organelles.

End Result:Two identical cells that will re-enter interphase begin the process again.

Cell division phase - two parts to cell division.

1. Mitosis - division of chromosomes and nucleus.• Both cells have complete set of blueprints.

Mitosis is how we reproduce non-sex cells (body cells).

Interphase

Anaphase

Metaphase

Prophase

Chromosomes duplicate.

Chromosomes line up (equator)

Duplicated chromosomes

Pulled apart

Parent cell

Identicaldaughter

cells

cytokinesis

Stages of Mitosis

Telophase

Copying of organelles and genetic material:• Leaving two complete sets of DNA.

(Deoxyribonucleic acid) • Chromosomes look like spaghetti.

Chromosomes condense becoming visible. • Nuclear membrane disappears.

• Centrioles move to opposite ends of the cell.

Centrioles

Sister Chromatids

Centrioles

Spindle fibers grow from centrioles • Attach to sister chromatids

• Align chromatids along the middle of the cell.

Spindle fibres

Sister Chromatids

Spindle fibers shorten and pull.• Separating sister chromatids.

• Identical chromatids at opposite ends of cell.

Sister chromatidsseparated

Cleavage of cell into two

New nuclear membranes forms.• Spindle fibers disappear

• Chromosomes uncondense (back to sphegetti).

CytokinesisAnimal: cell membrane

pinches cell into 2.

• Each daughter cell has copy of DNA, nucleus, organelles and cytoplasm.

Plant: Two new cells are formed as the cell wall (plate) grows down the middle of the cell.

• Leaving 2 identical daughter cells.

Click the following to proceed

http://bio.rutgers.edu/~gb101/lab2_mitosis/index2.html