Cell Division Created By Daniel Sylvester

What are we going to learn about cell division? What events take place during the three stages of the cell cycle? How does the structure of DNA (deoxyribonucleic acid) help account for the way in which DNA copies itself? How long does it take for a cell to go through the cycle?

 A single cell grows and then divides, forming two cells  Then the two cells divide into four and so on  This process occurs CONTINUOSLY

THREE STAGES IN CELL DIVISION Stage 1 - Interphase T The stage before the cell divides and is when the cell, makes a copy of its DNA and prepares to divide into two. Mitosis Stage 2 - Mitosis The stage when the cell’s nucleus divides into nuclei and one copy of the DNA is given to each of the daughter cells. Cytokinesis Stage 3 - Cytokinesis The final stage in cell division and when the cell’s cytoplasm divides and the organelles are distributed into both cells

INTERPHASE There are three parts to Interphase There are three parts to Interphase: Part 1 - The cell grows to its maximum size and makes food or other materials it needs. Part 1 - The cell grows to its maximum size and makes food or other materials it needs. Part 2 - The cell makes an exact replica of its DNA in its nucleus. Part 2 - The cell makes an exact replica of its DNA in its nucleus. Part 3 - Preparation for cell division begins. The cell produces structures that it will use to divide into two new cells. Part 3 - Preparation for cell division begins. The cell produces structures that it will use to divide into two new cells.

TThe thread-like chromatin in the nucleus condenses to form double–rod structures called chromosomes. TThe chromatins separate from each other and move to opposite sides of the cell. TTwo nuclei then form around the chromosomes.

CYTOKINESIS The cytoplasm divides and then the materials are given to each of the daughter cells When this stage is complete two new cells are formed.

Animal Cell Cytokinesis During cytokenesis in animal cells the cell membrane squeezes together around the middle of the cell. The cytoplasm pinches into two cells.

Plant Cell Cytokenesis Cytokenesis in plant cells are different because their cell wall cannot squeeze together. A structure called cell plate forms across the middle of the cell instead

THE STRUCTURE OF DNA HELPS REPLICATION BECAUSE THE WAY THAT WHICH NITROGEN BASES PAIR THEMSELVES WITH ONE ANOTHER. THE ORDER OF THE BASES IN EACH NEW DNA MOLECULE EXACTLY MATCH THE ORDER IN THE OLD DNA MOLECULE How Does DNA’s Structure Help Account For The Way In Which DNA Copies Itself

HOW LONG DOES IT TAKE FOR A CELL TO GO THROUGH THE CYCLE? IT DEPENDS ON THE CELL. SOME TAKE HOURS

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