chapter 10
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Chapter 10. Cell Growth And Division. I. Cell Growth. DNA. 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 _______ - PowerPoint PPT PresentationTRANSCRIPT
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
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