Chapter 10

Cell Growth And Division

I. Cell Growth– A. Limits to Cell Growth– 2 reasons cells divide rather than

continuing to grow indefinitely:• 1) larger a cell grows,the more

demands on its _______– will not be making enough copies of

DNA as size increases---This would cause an information crisis.

• 2) difficult to move waste and nutrients across cell

– rate @ which waste products leave cell depends on _______________________ of cell=total area of cell membrane

DNA

Surface area

– rate @ which food and Oxygen are used up and waste produced depends on _____________________

– RATIO OF SURFACE AREA TO VOLUME-assuming a cube shape,surface area=l x w x 6…..volume= lx w x h…. ratio = SA /volume

Cell volume

Cell Size

Surface Area (length x width x 6)

Volume (length x width x height)

Ratio of Surface Area to Volume

Ratio of Surface Area to Volume in Cells

Section 10-1

• Volume increases faster than surface area/CAUSING RATIO TO __________________..causing serious problems for cell

decrease

B. Division of Cell

-A cell divides into 2 daughter cells =_______________________________

– This happens before a cell can get too large

– DNA ___________________before cell division,solving info crisis.

Cell division replicates

II. Cell Division

• ***simpler in prokaryotes– A. chromosomes –carries genetic info in

eukaryotes– made up of ____________ and proteins– cells of every organism have a

specific # of Chromosomes– humans have___ Chromosomes– fruit flies have 8– usually not visible except in cell

division,when they condense– ___________________before cell division

DNA

46

Replicates or copies

–each Chromosome consists of 2 identical __________________,which separate from each other in cell division

–chromatids attached @__________________,usually near middle

chromatids

centromere

B. Cell Cycle

– ________________________is in- between phase

– ______________________is the series of events that a cell goes through during growth and division….Where the cell grows,prepare for division,divides into 2 daughter cells

interphase Cell Cycle

–4 phases• M= _______________________________• S= ________________________________• G1 and G2=

________________________________________________________

Mitosis and cytokinesis Chromsomes

replicate & DNA synthesis,some proteins synthesize

G1=cell growth/G2= organelles and molecules produced

M phase

G2 phase

S phase

G1 phase

Figure 10–4 The Cell Cycle

Section 10-2

ANAPHASE

1) Prophase

– Longest phase– Chromosomes become visible– _______________________,2 tiny structures

near nuclear envelope-separate and take positions on opposite ends of nucleus

– Centrosome region helps organize __________________-microtubules that help separate chromosomes

– Chromosomes attach to __________________________

– @ end chromosomes coil tightly and nuclear envelope disappears

centrioles

spindle Spindle fibers

• 2) Metaphase-• chromosomes line up @ center• Centromeres go to 2 poles

• 3) Anaphase-• Centromeres split• Chromatids separate and become individual

_____________________• New chromosomes go to opposite poles and then

stop moving

chromosomes

• 4) Telophase-• Chromosomes disperse into tangle of

material• New nuclear envelopes• Spindle breaks apart• Nucleolus becomes visible

D. Cytokinesis-divison of cytoplasm– Usually along w/ Telophase– Cell plate forms in plants that becomes the

______________________________

CELL WALL

III.

• _____________________= disorder in which some of the body’s cells lose the ability to regulate growth

• They do not respond to signals that regulate growth• Divide uncontrollably,making

___________________(masses of cells)• _____________=protein that regulates normal cell

cycle (in eukaryotes)

cancer tumors

cyclins

Video Conten

ts

Videos

• Click a hyperlink to choose a video.• Animal Cell Mitosis• Animal Cell Cytokinesis

Video 1

• Click the image to play the video segment.

Video 1

Animal Cell Mitosis

Video 2

• Click the image to play the video segment.

Video 2

Animal Cell Cytokinesis