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Cell Growth and Division Chapter 10
Cell Growth and Division
Chapter 10
Why Must Cells Divide?• Cells divide to make more cells because of:- DNA overload:
a) When a cell becomes too large, the demands that the cell places on the DNA become too great and the cell must undergo mitosis.
Why Must Cells Divide?Food entering the cell and Waste exiting the cell:a) Surface Area to Volume Ratio of cells must stay high enough to allow nutrients in and waste out. The larger a cell is, the smaller it’s surface area to volume ratio becomes:
Why Must Cells Divide?b) If a cell becomes too large the food and oxygen needed by the cell take too long to reach the insides of the cell.
c) If a cell becomes too large, the waste created by the cell takes too long to be removed by the cell and it can build up within the cell, eventually killing the cell.
Life Spans of Different Human CellsBrain Cells 30 - 50 yearsRed Blood Cells 120 daysPlatelets 10 daysStomach Lining Cells 2 daysLiver Cells 200 daysIntestine Lining Cells 3 daysSkin cells 7-20 daysSperm Cells 3 daysMature Egg Cells 2 days
DNA and Cell Division• DNA is the material that stores and
transmits genetic information.
• When cells divide, each new cell must receive a complete copy of the parent cell’s genetic information.
Chromosomes• When cells prepare to divide, their DNA
condenses into structures called chromosomes.
• Each organism has a specific number of chromosomes in its cells – Human cells contain 46 chromosomes
• Chromosome structure– Made up of DNA and protein– Contain two identical halves called
“sister” chromatids prior to cell division.– Each pair of chromatids are attached at a
central point called a centromere.
The Cell Cycle• The cell cycle is a series of events that
cells go through as they grow and divide
Stages of the Cell Cycle1) G1 Phase – cell grows2) S phase – DNA is replicated in cell3) G2 phase – cell prepares to divide4) M phase – cell division occurs.
Inte
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Steps of Cell Division (the M phase)
• Mitosis – the division of the cell’s nucleus
• Cytokinesis – the division of the cell’s cytoplasm
Steps of Mitosis• Prophase
– The chromosomes become visible– The centrioles move to opposite sides of the nucleus– The spindle fibers begin to form– The nuclear membrane breaks down
Steps of Mitosis•Metaphase
– The chromosomes line up across the center of the cell.
Steps of Mitosis•Anaphase
– The sister chromatids separate to become individual chromosomes.
– The chromosomes move to opposite ends of the cell.
Steps of Mitosis• Telophase
– Chromosomes begin to uncoil– Nuclear envelope reforms around each
cluster of chromosomes.– The spindle begins to break apart
Cell Pictures Practice
Anaphase
Cell Pictures Review
Metaphase
Cell Pictures Review
Telophase
Cell Pictures Review
Prophase
Cell Pictures Review
Metaphase
Cell Pictures Review
Telophase
Cell Pictures Review
Prophase
Cell Pictures Review
Prophase
Cell Pictures Review
Anaphase
Cell Pictures Review
Telophase
Cell Pictures Review
Metaphase
Cell Pictures Review
Metaphase
Cell Pictures Review
Telophase
Cell Pictures Review
Prophase
Cell Pictures Review
Anaphase
Cytokinesis• Cytokinesis – the division
of the cell’s cytoplasm.– In animal cells, the cell
membrane is pinchedinward until cytoplasm is divided into two equal parts.
– In plant cells, a cell plateforms between the two new nuclei.
– video
I – Interphase
P – Prophase
M – Metaphase
A – Anaphase
T – Telophase
C – Cytokinesis
Stages Of The Cell’s Life Cycle
I pee Mat! See!!!
Growth - 1Synthesis
Growth - 2
Cell Life Cycle Practice!!!!!
Interphase!!!!!!!
Cell Life Cycle Practice!!!!!
Prophase!!!!!!!
Cell Life Cycle Practice!!!!!
Metaphase!!!!!!!
Cell Life Cycle Practice!!!!!
Anaphase!!!!!!!
Cell Life Cycle Practice!!!!!
Telophase!!!!!!!
Cell Life Cycle Practice!!!!!
Cytokinesis!!!!!!!
Uncontrolled Cell Growth• Cancer – a disorder in which some of
the body’s cells lose the ability to control cell growth and division. – Cancer cells form masses called tumors
that can damage surrounding tissues.– Cancer cells may break loose and
spread through the body (metastasis) causing serious medical problems or death.
– Cancer can be caused by external factors such as tobacco, radiation exposure, and viral infection.
