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.

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