would it be ok if cells continued to grow forever? explain objectives: what does the cell do in...
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TUESDAY, MARCH 9, 2010
Would it be ok if cells continued to grow forever? Explain
OBJECTIVES:What does the cell do in
order to solve the dilemma of growing forever
What are the stages of the cell cycle
DUE AT THE END OF CLASS:
Cell Size Lab from yesterday
HOMEWORK: Read section 9.1 and
complete assessment questions on p. 247
LOOKING BACK AT OUR LAB…
DOES CELL SIZE EFFECT THE CELL’S ABILITY TO FUNCTION EFFICIENTLY?
YES!!!
Cells are limited in how large they can be. This is because the
surface area to volume ratio does not stay the same as their
size increases. Because of this, it is harder for a large cell to pass
materials in and out of the membrane, and to move materials
through the cell.
SURFACE AREA TO VOLUME RATIO
Surface area-
Volume-
WHY WOULD A HIGH RATIO OF SURFACE AREA TO
VOLUME BENEFIT A CELL?
Transport of substances
Cellular communications
Once a cell reaches its size limit, something
must happen- either is will stop growing or it will divide. Most cells will eventually divide. Cell division not only
prevents the cell from becoming too large, but
it also is the way cell reproduces so that you grow and heal certain
injuries.
TUESDAY, MARCH 9, 2010
Would it be ok if cells continued to grow forever? Explain
OBJECTIVES:What does the cell do in
order to solve the dilemma of growing forever
What are the stages of the cell cycle
DUE AT THE END OF CLASS:
Cell Size Lab from yesterday
HOMEWORK: Read section 9.1 and
complete assessment questions on p. 247
THE CELL CYCLEEach time a cell goes through one complete cycle, it becomes two cells. When the cycle is repeated continuously, the result is a continuous production of new cells.
3 Main Stages:
Interphase
Mitosis
Cytokinesis
STAGES OF INTERPHASEDuring interphase, the cell grows, develops into a mature
functioning cell, duplicates its DNA, and prepares for division.
G1-
Cell is growing
S- SynthesisCell copies its DNA in preparation for cell division.
G2-
Cell prepares for division of nucleus (mitosis)
STAGES OF MITOSIS•Prophase
•Metaphase
•Anaphase
•Telophase
CYTOKINESISProcess of dividing the cytoplasm